Tcl Source Code

/*
 * tclIOUtil.c --
 *
 *	This file contains the implementation of Tcl's generic filesystem
 *	code, which supports a pluggable filesystem architecture allowing both
 *	platform specific filesystems and 'virtual filesystems'. All
 *	filesystem access should go through the functions defined in this
 *	file. Most of this code was contributed by Vince Darley.
 *
 *	Parts of this file are based on code contributed by Karl Lehenbauer,
 *	Mark Diekhans and Peter da Silva.
 *
 * Copyright (c) 1991-1994 The Regents of the University of California.
 * Copyright (c) 1994-1997 Sun Microsystems, Inc.
 * Copyright (c) 2001-2004 Vincent Darley.
 *
 * See the file "license.terms" for information on usage and redistribution of
 * this file, and for a DISCLAIMER OF ALL WARRANTIES.
................................................................................
#include <sys/statfs.h>
#endif
#endif

/*
 * struct FilesystemRecord --
 *
 * A filesystem record is used to keep track of each filesystem currently
 * registered with the core, in a linked list.
 */

typedef struct FilesystemRecord {
    ClientData clientData;	/* Client specific data for the new filesystem
				 * (can be NULL) */
    const Tcl_Filesystem *fsPtr;/* Pointer to filesystem dispatch table. */
    struct FilesystemRecord *nextPtr;
				/* The next filesystem registered to Tcl, or
				 * NULL if no more. */
    struct FilesystemRecord *prevPtr;
				/* The previous filesystem registered to Tcl,
				 * or NULL if no more. */
} FilesystemRecord;

/*
 * This structure holds per-thread private copy of the current directory
 * maintained by the global cwdPathPtr. This structure holds per-thread
 * private copies of some global data. This way we avoid most of the
 * synchronization calls which boosts performance, at cost of having to update
 * this information each time the corresponding epoch counter changes.
 */

typedef struct {
    int initialized;
    size_t cwdPathEpoch;


    size_t filesystemEpoch;
    Tcl_Obj *cwdPathPtr;



    ClientData cwdClientData;
    FilesystemRecord *filesystemList;
    size_t claims;
} ThreadSpecificData;

/*
 * Prototypes for functions defined later in this file.
 */

static Tcl_NRPostProc	EvalFileCallback;
static FilesystemRecord*FsGetFirstFilesystem(void);
static void		FsThrExitProc(ClientData cd);
static Tcl_Obj *	FsListMounts(Tcl_Obj *pathPtr, const char *pattern);
static void		FsAddMountsToGlobResult(Tcl_Obj *resultPtr,
................................................................................
static void		Claim(void);
static void		Disclaim(void);

static void *		DivertFindSymbol(Tcl_Interp *interp,
			    Tcl_LoadHandle loadHandle, const char *symbol);
static void		DivertUnloadFile(Tcl_LoadHandle loadHandle);

/*
 * These form part of the native filesystem support. They are needed here
 * because we have a few native filesystem functions (which are the same for
 * win/unix) in this file. There is no need to place them in tclInt.h, because
 * they are not (and should not be) used anywhere else.
 */

MODULE_SCOPE const char *const		tclpFileAttrStrings[];
MODULE_SCOPE const TclFileAttrProcs	tclpFileAttrProcs[];
 
/*
 * Declare the native filesystem support. These functions should be considered
 * private to Tcl, and should really not be called directly by any code other
 * than this file (i.e. neither by Tcl's core nor by extensions). Similarly,

 * the old string-based Tclp... native filesystem functions should not be
 * called.
 *
 * The correct API to use now is the Tcl_FS... set of functions, which ensure
 * correct and complete virtual filesystem support.
 *
 * We cannot make all of these static, since some of them are implemented in
 * the platform-specific directories.
 */

static Tcl_FSFilesystemSeparatorProc NativeFilesystemSeparator;
static Tcl_FSFreeInternalRepProc NativeFreeInternalRep;
static Tcl_FSFileAttrStringsProc NativeFileAttrStrings;
static Tcl_FSFileAttrsGetProc	NativeFileAttrsGet;
static Tcl_FSFileAttrsSetProc	NativeFileAttrsSet;

/*










 * The only reason these functions are not static is that they are either
 * called by code in the native (win/unix) directories or they are actually
 * implemented in those directories. They should simply not be called by code
 * outside Tcl's native filesystem core i.e. they should be considered


 * 'static' to Tcl's filesystem code (if we ever built the native filesystem
 * support into a separate code library, this could actually be enforced).
 */

Tcl_FSFilesystemPathTypeProc	TclpFilesystemPathType;
Tcl_FSInternalToNormalizedProc	TclpNativeToNormalized;
Tcl_FSStatProc			TclpObjStat;
Tcl_FSAccessProc		TclpObjAccess;
Tcl_FSMatchInDirectoryProc	TclpMatchInDirectory;
................................................................................
Tcl_FSCreateDirectoryProc	TclpObjCreateDirectory;
Tcl_FSCopyDirectoryProc		TclpObjCopyDirectory;
Tcl_FSRemoveDirectoryProc	TclpObjRemoveDirectory;
Tcl_FSLinkProc			TclpObjLink;
Tcl_FSListVolumesProc		TclpObjListVolumes;

/*
 * Define the native filesystem dispatch table. If necessary, it is ok to make
 * this non-static, but it should only be accessed by the functions actually
 * listed within it (or perhaps other helper functions of them). Anything
 * which is not part of this 'native filesystem implementation' should not be
 * delving inside here!
 */

const Tcl_Filesystem tclNativeFilesystem = {
    "native",
    sizeof(Tcl_Filesystem),
    TCL_FILESYSTEM_VERSION_2,
    TclNativePathInFilesystem,
................................................................................
    /* Needs casts since we're using version_2. */
    (Tcl_FSLoadFileProc *) TclpDlopen,
    (Tcl_FSGetCwdProc *) TclpGetNativeCwd,
    TclpObjChdir
};

/*
 * Define the tail of the linked list. Note that for unconventional uses of
 * Tcl without a native filesystem, we may in the future wish to modify the
 * current approach of hard-coding the native filesystem in the lookup list
 * 'filesystemList' below.
 *
 * We initialize the record so that it thinks one file uses it. This means it
 * will never be freed.
 */

static FilesystemRecord nativeFilesystemRecord = {
    NULL,
    &tclNativeFilesystem,
    NULL,
    NULL
};

/*
 * This is incremented each time we modify the linked list of filesystems. Any
 * time it changes, all cached filesystem representations are suspect and must
 * be freed. For multithreading builds, change of the filesystem epoch will
 * trigger cache cleanup in all threads.
 */

static size_t theFilesystemEpoch = 1;

/*
 * Stores the linked list of filesystems. A 1:1 copy of this list is also
 * maintained in the TSD for each thread. This is to avoid synchronization
 * issues.
 */

static FilesystemRecord *filesystemList = &nativeFilesystemRecord;
TCL_DECLARE_MUTEX(filesystemMutex)

/*
 * Used to implement Tcl_FSGetCwd in a file-system independent way.
 */

static Tcl_Obj *cwdPathPtr = NULL;
static size_t cwdPathEpoch = 0;
static ClientData cwdClientData = NULL;
TCL_DECLARE_MUTEX(cwdMutex)

static Tcl_ThreadDataKey fsDataKey;

/*
 * One of these structures is used each time we successfully load a file from
 * a file system by way of making a temporary copy of the file on the native
 * filesystem. We need to store both the actual unloadProc/clientData
 * combination which was used, and the original and modified filenames, so
 * that we can correctly undo the entire operation when we want to unload the
 * code.
 */

typedef struct {
    Tcl_LoadHandle loadHandle;
    Tcl_FSUnloadFileProc *unloadProcPtr;
    Tcl_Obj *divertedFile;
    const Tcl_Filesystem *divertedFilesystem;
    ClientData divertedFileNativeRep;
} FsDivertLoad;
 
/*
 * The following functions are obsolete string based APIs, and should be
 * removed in a future release (Tcl 9 would be a good time).
 */

/* Obsolete */
int
Tcl_Stat(
    const char *path,		/* Path of file to stat (in current CP). */
    struct stat *oldStyleBuf)	/* Filled with results of stat call. */
{
    int ret;
    Tcl_StatBuf buf;
    Tcl_Obj *pathPtr = Tcl_NewStringObj(path,-1);

    Tcl_IncrRefCount(pathPtr);
................................................................................
    }
    return ret;
}
 
/* Obsolete */
int
Tcl_Access(
    const char *path,		/* Path of file to access (in current CP). */

    int mode)			/* Permission setting. */
{
    int ret;
    Tcl_Obj *pathPtr = Tcl_NewStringObj(path,-1);

    Tcl_IncrRefCount(pathPtr);
    ret = Tcl_FSAccess(pathPtr,mode);
................................................................................

    return ret;
}
 
/* Obsolete */
Tcl_Channel
Tcl_OpenFileChannel(
    Tcl_Interp *interp,		/* Interpreter for error reporting; can be
				 * NULL. */
    const char *path,		/* Name of file to open. */
    const char *modeString,	/* A list of POSIX open modes or a string such
				 * as "rw". */
    int permissions)		/* If the open involves creating a file, with
				 * what modes to create it? */
{
    Tcl_Channel ret;
    Tcl_Obj *pathPtr = Tcl_NewStringObj(path,-1);

    Tcl_IncrRefCount(pathPtr);
    ret = Tcl_FSOpenFileChannel(interp, pathPtr, modeString, permissions);
    Tcl_DecrRefCount(pathPtr);
................................................................................
    TclDStringAppendObj(cwdPtr, cwd);
    Tcl_DecrRefCount(cwd);
    return Tcl_DStringValue(cwdPtr);
}
 
int
Tcl_EvalFile(
    Tcl_Interp *interp,		/* Interpreter in which to process file. */
    const char *fileName)	/* Name of file to process. Tilde-substitution
				 * will be performed on this name. */

{
    int ret;
    Tcl_Obj *pathPtr = Tcl_NewStringObj(fileName,-1);

    Tcl_IncrRefCount(pathPtr);
    ret = Tcl_FSEvalFile(interp, pathPtr);
    Tcl_DecrRefCount(pathPtr);
    return ret;
}
 
/*
 * Now move on to the basic filesystem implementation.
 */

static void
FsThrExitProc(
    ClientData cd)
{
    ThreadSpecificData *tsdPtr = cd;
    FilesystemRecord *fsRecPtr = NULL, *tmpFsRecPtr = NULL;

    /*
     * Trash the cwd copy.
     */

    if (tsdPtr->cwdPathPtr != NULL) {
	Tcl_DecrRefCount(tsdPtr->cwdPathPtr);
	tsdPtr->cwdPathPtr = NULL;
    }
    if (tsdPtr->cwdClientData != NULL) {
	NativeFreeInternalRep(tsdPtr->cwdClientData);
    }

    /*
     * Trash the filesystems cache.
     */

    fsRecPtr = tsdPtr->filesystemList;
    while (fsRecPtr != NULL) {
	tmpFsRecPtr = fsRecPtr->nextPtr;
	fsRecPtr->fsPtr = NULL;
	ckfree(fsRecPtr);
................................................................................
    }
}
 
/*
 *----------------------------------------------------------------------
 *
 * TclFSCwdPointerEquals --
 *
 *	Check whether the current working directory is equal to the path
 *	given.
 *
 * Results:
 *	1 (equal) or 0 (un-equal) as appropriate.

 *
 * Side effects:
 *	If the paths are equal, but are not the same object, this method will


 *	modify the given pathPtrPtr to refer to the same object. In this case
 *	the object pointed to by pathPtrPtr will have its refCount
 *	decremented, and it will be adjusted to point to the cwd (with a new
 *	refCount).
 *


 *----------------------------------------------------------------------
 */

int
TclFSCwdPointerEquals(
    Tcl_Obj **pathPtrPtr)
{
................................................................................
	int len1, len2;
	const char *str1, *str2;

	str1 = TclGetStringFromObj(tsdPtr->cwdPathPtr, &len1);
	str2 = TclGetStringFromObj(*pathPtrPtr, &len2);
	if ((len1 == len2) && !memcmp(str1, str2, len1)) {
	    /*
	     * They are equal, but different objects. Update so they will be
	     * the same object in the future.
	     */

	    Tcl_DecrRefCount(*pathPtrPtr);
	    *pathPtrPtr = tsdPtr->cwdPathPtr;
	    Tcl_IncrRefCount(*pathPtrPtr);
	    return 1;
	} else {
................................................................................
    fsRecPtr = filesystemList;
    while (fsRecPtr != NULL) {
	tmpFsRecPtr = fsRecPtr;
	fsRecPtr = fsRecPtr->nextPtr;
    }

    /*
     * Refill the cache honouring the order.
     */

    list = NULL;
    fsRecPtr = tmpFsRecPtr;
    while (fsRecPtr != NULL) {
	tmpFsRecPtr = ckalloc(sizeof(FilesystemRecord));
	*tmpFsRecPtr = *fsRecPtr;
................................................................................
	    && (tsdPtr->filesystemEpoch != theFilesystemEpoch))) {
	FsRecacheFilesystemList();
    }
    return tsdPtr->filesystemList;
}
 
/*
 * The epoch can be changed by filesystems being added or removed, by changing
 * the "system encoding" and by env(HOME) changing.
 */

int
TclFSEpochOk(
    size_t filesystemEpoch)
{
    return (filesystemEpoch == 0 || filesystemEpoch == theFilesystemEpoch);
................................................................................
{
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&fsDataKey);

    return tsdPtr->filesystemEpoch;
}
 
/*
 * If non-NULL, clientData is owned by us and must be freed later.
 */

static void
FsUpdateCwd(
    Tcl_Obj *cwdObj,
    ClientData clientData)
{
................................................................................
    }

    if (cwdObj == NULL) {
	cwdPathPtr = NULL;
	cwdClientData = NULL;
    } else {
	/*
	 * This must be stored as string obj!
	 */

	cwdPathPtr = Tcl_NewStringObj(str, len);
	Tcl_IncrRefCount(cwdPathPtr);
	cwdClientData = TclNativeDupInternalRep(clientData);
    }

................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * TclFinalizeFilesystem --
 *
 *	Clean up the filesystem. After this, calls to all Tcl_FS... functions
 *	will fail.
 *
 *	We will later call TclResetFilesystem to restore the FS to a pristine
 *	state.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Frees any memory allocated by the filesystem.
 *
 *----------------------------------------------------------------------
 */

void
TclFinalizeFilesystem(void)
{
    FilesystemRecord *fsRecPtr;

    /*
     * Assumption that only one thread is active now. Otherwise we would need
     * to put various mutexes around this code.

     */

    if (cwdPathPtr != NULL) {
	Tcl_DecrRefCount(cwdPathPtr);
	cwdPathPtr = NULL;
	cwdPathEpoch = 0;
    }
................................................................................
     */

    fsRecPtr = filesystemList;
    while (fsRecPtr != NULL) {
	FilesystemRecord *tmpFsRecPtr = fsRecPtr->nextPtr;

	/*
	 * The native filesystem is static, so we don't free it.
	 */

	if (fsRecPtr != &nativeFilesystemRecord) {
	    ckfree(fsRecPtr);
	}
	fsRecPtr = tmpFsRecPtr;
    }
    if (++theFilesystemEpoch == 0) {
	++theFilesystemEpoch;
    }
    filesystemList = NULL;

    /*
     * Now filesystemList is NULL. This means that any attempt to use the
     * filesystem is likely to fail.
     */

#ifdef _WIN32
    TclWinEncodingsCleanup();
#endif
}
 
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSRegister --
 *
 *	Insert the filesystem function table at the head of the list of
 *	functions which are used during calls to all file-system operations.
 *	The filesystem will be added even if it is already in the list. (You

 *	can use Tcl_FSData to check if it is in the list, provided the
 *	ClientData used was not NULL).
 *

 *	Note that the filesystem handling is head-to-tail of the list. Each
 *	filesystem is asked in turn whether it can handle a particular
 *	request, until one of them says 'yes'. At that point no further
 *	filesystems are asked.
 *
 *	In particular this means if you want to add a diagnostic filesystem
 *	(which simply reports all fs activity), it must be at the head of the

 *	list: i.e. it must be the last registered.
 *
 * Results:
 *	Normally TCL_OK; TCL_ERROR if memory for a new node in the list could
 *	not be allocated.
 *
 * Side effects:
 *	Memory allocated and modifies the link list for filesystems.

 *
 *----------------------------------------------------------------------
 */

int
Tcl_FSRegister(
    ClientData clientData,	/* Client specific data for this fs. */
    const Tcl_Filesystem *fsPtr)/* The filesystem record for the new fs. */
{
    FilesystemRecord *newFilesystemPtr;

    if (fsPtr == NULL) {
	return TCL_ERROR;
    }

    newFilesystemPtr = ckalloc(sizeof(FilesystemRecord));

    newFilesystemPtr->clientData = clientData;
    newFilesystemPtr->fsPtr = fsPtr;

    /*
     * Is this lock and wait strictly speaking necessary? Since any iterators
     * out there will have grabbed a copy of the head of the list and be
     * iterating away from that, if we add a new element to the head of the
     * list, it can't possibly have any effect on any of their loops. In fact
     * it could be better not to wait, since we are adjusting the filesystem
     * epoch, any cached representations calculated by existing iterators are
     * going to have to be thrown away anyway.
     *
     * However, since registering and unregistering filesystems is a very rare
     * action, this is not a very important point.
     */

    Tcl_MutexLock(&filesystemMutex);

    newFilesystemPtr->nextPtr = filesystemList;
    newFilesystemPtr->prevPtr = NULL;
    if (filesystemList) {
	filesystemList->prevPtr = newFilesystemPtr;
    }
    filesystemList = newFilesystemPtr;

    /*
     * Increment the filesystem epoch counter, since existing paths might
     * conceivably now belong to different filesystems.
     */

    if (++theFilesystemEpoch == 0) {
	++theFilesystemEpoch;
    }
    Tcl_MutexUnlock(&filesystemMutex);
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSUnregister --
 *
 *	Remove the passed filesystem from the list of filesystem function
 *	tables. It also ensures that the built-in (native) filesystem is not
 *	removable, although we may wish to change that decision in the future
 *	to allow a smaller Tcl core, in which the native filesystem is not
 *	used at all (we could, say, initialise Tcl completely over a network
 *	connection).
 *
 * Results:
 *	TCL_OK if the function pointer was successfully removed, TCL_ERROR
 *	otherwise.
 *
 * Side effects:
 *	Memory may be deallocated (or will be later, once no "path" objects
 *	refer to this filesystem), but the list of registered filesystems is
 *	updated immediately.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_FSUnregister(
    const Tcl_Filesystem *fsPtr)/* The filesystem record to remove. */
................................................................................
{
    int retVal = TCL_ERROR;
    FilesystemRecord *fsRecPtr;

    Tcl_MutexLock(&filesystemMutex);

    /*
     * Traverse the 'filesystemList' looking for the particular node whose
     * 'fsPtr' member matches 'fsPtr' and remove that one from the list.
     * Ensure that the "default" node cannot be removed.
     */

    fsRecPtr = filesystemList;
    while ((retVal == TCL_ERROR) && (fsRecPtr != &nativeFilesystemRecord)) {
	if (fsRecPtr->fsPtr == fsPtr) {
	    if (fsRecPtr->prevPtr) {
		fsRecPtr->prevPtr->nextPtr = fsRecPtr->nextPtr;
................................................................................
		filesystemList = fsRecPtr->nextPtr;
	    }
	    if (fsRecPtr->nextPtr) {
		fsRecPtr->nextPtr->prevPtr = fsRecPtr->prevPtr;
	    }

	    /*

	     * Increment the filesystem epoch counter, since existing paths
	     * might conceivably now belong to different filesystems. This
	     * should also ensure that paths which have cached the filesystem
	     * which is about to be deleted do not reference that filesystem
	     * (which would of course lead to memory exceptions).
	     */

	    if (++theFilesystemEpoch == 0) {
		++theFilesystemEpoch;
	    }

	    ckfree(fsRecPtr);
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSMatchInDirectory --
 *
 *	This routine is used by the globbing code to search a directory for
 *	all files which match a given pattern. The appropriate function for
 *	the filesystem to which pathPtr belongs will be called. If pathPtr
 *	does not belong to any filesystem and if it is NULL or the empty
 *	string, then we assume the pattern is to be matched in the current
 *	working directory. To avoid have the Tcl_FSMatchInDirectoryProc for
 *	each filesystem from having to deal with this issue, we create a
 *	pathPtr on the fly (equal to the cwd), and then remove it from the
 *	results returned. This makes filesystems easy to write, since they can
 *	assume the pathPtr passed to them is an ordinary path. In fact this
 *	means we could remove such special case handling from Tcl's native
 *	filesystems.
 *
 *	If 'pattern' is NULL, then pathPtr is assumed to be a fully specified
 *	path of a single file/directory which must be checked for existence
 *	and correct type.
 *
 * Results:
 *
 *	The return value is a standard Tcl result indicating whether an error
 *	occurred in globbing. Error messages are placed in interp, but good
 *	results are placed in the resultPtr given.

 *
 *	Recursive searches, e.g.
 *		glob -dir $dir -join * pkgIndex.tcl
 *	which must recurse through each directory matching '*' are handled
 *	internally by Tcl, by passing specific flags in a modified 'types'
 *	parameter. This means the actual filesystem only ever sees patterns
 *	which match in a single directory.
 *
 * Side effects:
 *	The interpreter may have an error message inserted into it.


 *
 *----------------------------------------------------------------------
 */

int
Tcl_FSMatchInDirectory(
    Tcl_Interp *interp,		/* Interpreter to receive error messages, but
				 * may be NULL. */
    Tcl_Obj *resultPtr,		/* List object to receive results. */
    Tcl_Obj *pathPtr,		/* Contains path to directory to search. */

    const char *pattern,	/* Pattern to match against. */



    Tcl_GlobTypeData *types)	/* Object containing list of acceptable types.
				 * May be NULL. In particular the directory
				 * flag is very important. */

{
    const Tcl_Filesystem *fsPtr;
    Tcl_Obj *cwd, *tmpResultPtr, **elemsPtr;
    int resLength, i, ret = -1;

    if (types != NULL && (types->type & TCL_GLOB_TYPE_MOUNT)) {
	/*
	 * We don't currently allow querying of mounts by external code (a
	 * valuable future step), so since we're the only function that
	 * actually knows about mounts, this means we're being called
	 * recursively by ourself. Return no matches.
	 */

	return TCL_OK;
    }

    if (pathPtr != NULL) {
	fsPtr = Tcl_FSGetFileSystemForPath(pathPtr);
    } else {
	fsPtr = NULL;
    }


    /*
     * Check if we've successfully mapped the path to a filesystem within
     * which to search.
     */

    if (fsPtr != NULL) {
	if (fsPtr->matchInDirectoryProc == NULL) {
	    Tcl_SetErrno(ENOENT);
	    return -1;
	}
	ret = fsPtr->matchInDirectoryProc(interp, resultPtr, pathPtr, pattern,
		types);
	if (ret == TCL_OK && pattern != NULL) {
	    FsAddMountsToGlobResult(resultPtr, pathPtr, pattern, types);
	}
	return ret;
    }


    /*
     * If the path isn't empty, we have no idea how to match files in a
     * directory which belongs to no known filesystem.
     */

    if (pathPtr != NULL && TclGetString(pathPtr)[0] != '\0') {
	Tcl_SetErrno(ENOENT);
	return -1;
    }

    /*
     * We have an empty or NULL path. This is defined to mean we must search
     * for files within the current 'cwd'. We therefore use that, but then
     * since the proc we call will return results which include the cwd we
     * must then trim it off the front of each path in the result. We choose
     * to deal with this here (in the generic code), since if we don't, every
     * single filesystem's implementation of Tcl_FSMatchInDirectory will have
     * to deal with it for us.
     */

    cwd = Tcl_FSGetCwd(NULL);
    if (cwd == NULL) {
	if (interp != NULL) {
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "glob couldn't determine the current working directory",
................................................................................
	Tcl_IncrRefCount(tmpResultPtr);
	ret = fsPtr->matchInDirectoryProc(interp, tmpResultPtr, cwd, pattern,
		types);
	if (ret == TCL_OK) {
	    FsAddMountsToGlobResult(tmpResultPtr, cwd, pattern, types);

	    /*
	     * Note that we know resultPtr and tmpResultPtr are distinct.
	     */

	    ret = Tcl_ListObjGetElements(interp, tmpResultPtr,
		    &resLength, &elemsPtr);
	    for (i=0 ; ret==TCL_OK && i<resLength ; i++) {
		ret = Tcl_ListObjAppendElement(interp, resultPtr,
			TclFSMakePathRelative(interp, elemsPtr[i], cwd));
................................................................................
    return ret;
}
 
/*
 *----------------------------------------------------------------------
 *
 * FsAddMountsToGlobResult --
 *
 *	This routine is used by the globbing code to take the results of a
 *	directory listing and add any mounted paths to that listing. This is
 *	required so that simple things like 'glob *' merge mounts and listings
 *	correctly.

 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Modifies the resultPtr.
 *
 *----------------------------------------------------------------------
 */

static void
FsAddMountsToGlobResult(
    Tcl_Obj *resultPtr,		/* The current list of matching paths; must
				 * not be shared! */
    Tcl_Obj *pathPtr,		/* The directory in question. */
    const char *pattern,	/* Pattern to match against. */
    Tcl_GlobTypeData *types)	/* Object containing list of acceptable types.
				 * May be NULL. In particular the directory
				 * flag is very important. */
{
    int mLength, gLength, i;
    int dir = (types == NULL || (types->type & TCL_GLOB_TYPE_DIR));
    Tcl_Obj *mounts = FsListMounts(pathPtr, pattern);

    if (mounts == NULL) {
	return;
................................................................................
	    }
	}
	if (!found && dir) {
	    Tcl_Obj *norm;
	    int len, mlen;

	    /*
	     * We know mElt is absolute normalized and lies inside pathPtr, so
	     * now we must add to the result the right representation of mElt,
	     * i.e. the representation which is relative to pathPtr.
	     */

	    norm = Tcl_FSGetNormalizedPath(NULL, pathPtr);
	    if (norm != NULL) {
		const char *path, *mount;

		mount = TclGetStringFromObj(mElt, &mlen);
................................................................................
		    /*
		     * Deal with the root of the volume.
		     */

		    len--;
		}
		len++;		/* account for '/' in the mElt [Bug 1602539] */

		mElt = TclNewFSPathObj(pathPtr, mount + len, mlen - len
		    , TclFSPathEncoding(NULL, pathPtr));
		Tcl_ListObjAppendElement(NULL, resultPtr, mElt);
	    }
	    /*
	     * No need to increment gLength, since we don't want to compare
	     * mounts against mounts.
	     */
	}
    }

  endOfMounts:
    Tcl_DecrRefCount(mounts);
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSMountsChanged --
 *
 *	Notify the filesystem that the available mounted filesystems (or
 *	within any one filesystem type, the number or location of mount
 *	points) have changed.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The global filesystem variable 'theFilesystemEpoch' is incremented.

 *	The effect of this is to make all cached path representations invalid.
 *	Clearly it should only therefore be called when it is really required!
 *	There are a few circumstances when it should be called:
 *
 *	(1) when a new filesystem is registered or unregistered. Strictly
 *	speaking this is only necessary if the new filesystem accepts file
 *	paths as is (normally the filesystem itself is really a shell which

 *	hasn't yet had any mount points established and so its
 *	'pathInFilesystem' proc will always fail). However, for safety, Tcl
 *	always calls this for you in these circumstances.


 *
 *	(2) when additional mount points are established inside any existing

 *	filesystem (except the native fs)
 *
 *	(3) when any filesystem (except the native fs) changes the list of
 *	available volumes.


 *
 *	(4) when the mapping from a string representation of a file to a full,
 *	normalized path changes. For example, if 'env(HOME)' is modified, then

 *	any path containing '~' will map to a different filesystem location.
 *	Therefore all such paths need to have their internal representation
 *	invalidated.
 *
 *	Tcl has no control over (2) and (3), so any registered filesystem must
 *	make sure it calls this function when those situations occur.

 *
 *	(Note: the reason for the exception in 2,3 for the native filesystem
 *	is that the native filesystem by default claims all unknown files even
 *	if it really doesn't understand them or if they don't exist).


 *
 *----------------------------------------------------------------------
 */

void
Tcl_FSMountsChanged(
    const Tcl_Filesystem *fsPtr)
{
    /*
     * We currently don't do anything with this parameter. We could in the
     * future only invalidate files for this filesystem or otherwise take more
     * advanced action.


     */

    (void)fsPtr;

    /*
     * Increment the filesystem epoch counter, since existing paths might now
     * belong to different filesystems.
     */

    Tcl_MutexLock(&filesystemMutex);
    if (++theFilesystemEpoch == 0) {
	++theFilesystemEpoch;
    }
    Tcl_MutexUnlock(&filesystemMutex);
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSData --
 *
 *	Retrieve the clientData field for the filesystem given, or NULL if
 *	that filesystem is not registered.
 *
 * Results:
 *	A clientData value, or NULL. Note that if the filesystem was
 *	registered with a NULL clientData field, this function will return
 *	that NULL value.

 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

ClientData
Tcl_FSData(
    const Tcl_Filesystem *fsPtr) /* The filesystem record to query. */

{
    ClientData retVal = NULL;
    FilesystemRecord *fsRecPtr = FsGetFirstFilesystem();

    /*
     * Traverse the list of filesystems look for a particular one. If found,
     * return that filesystem's clientData (originally provided when calling
     * Tcl_FSRegister).
     */

    while ((retVal == NULL) && (fsRecPtr != NULL)) {
	if (fsRecPtr->fsPtr == fsPtr) {
	    retVal = fsRecPtr->clientData;
	}
	fsRecPtr = fsRecPtr->nextPtr;
................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * TclFSNormalizeToUniquePath --
 *
 *	Takes a path specification containing no ../, ./ sequences, and
 *	converts it into a unique path for the given platform. On Unix, this
 *	means the path must be free of symbolic links/aliases, and on Windows
 *	it means we want the long form, with that long form's case-dependence
 *	(which gives us a unique, case-dependent path).
 *

 * Results:
 *	The pathPtr is modified in place. The return value is the last byte
 *	offset which was recognised in the path string.
 *
 * Side effects:
 *	None (beyond the memory allocation for the result).
 *
 * Special notes:
 *	If the filesystem-specific normalizePathProcs can re-introduce ../, ./
 *	sequences into the path, then this function will not return the
 *	correct result. This may be possible with symbolic links on unix.
 *
 *	Important assumption: if startAt is non-zero, it must point to a
 *	directory separator that we know exists and is already normalized (so
 *	it is important not to point to the char just after the separator).
 *
 *---------------------------------------------------------------------------
 */

int
TclFSNormalizeToUniquePath(
    Tcl_Interp *interp,		/* Used for error messages. */
    Tcl_Obj *pathPtr,		/* The path to normalize in place. */
    int startAt)		/* Start at this char-offset. */





{
    FilesystemRecord *fsRecPtr, *firstFsRecPtr;

    int i;
    int isVfsPath = 0;
    const char *path;

    /*
     * Paths starting with a UNC prefix whose final character is a colon
     * are reserved for VFS use.  These names can not conflict with real
     * UNC paths per https://msdn.microsoft.com/en-us/library/gg465305.aspx
     * and rfc3986's definition of reg-name.
     *
     * We check these first to avoid useless calls to the native filesystem's
     * normalizePathProc.
     */
    path = Tcl_GetStringFromObj(pathPtr, &i);

    if ( (i >= 3) && ( (path[0] == '/' && path[1] == '/')
................................................................................
	    if (path[i] == path[0]) break;
	}
	--i;
	if (path[i] == ':') isVfsPath = 1;
    }

    /*
     * Call each of the "normalise path" functions in succession.
     */
    firstFsRecPtr = FsGetFirstFilesystem();

    Claim();

    if (!isVfsPath) {

	/*
	 * If we have a native filesystem handler, we call it first.  This is
	 * because the root of Tcl's filesystem is always a native filesystem
	 * (i.e., '/' on unix is native).
	 */

	for (fsRecPtr=firstFsRecPtr; fsRecPtr!=NULL; fsRecPtr=fsRecPtr->nextPtr) {
	    if (fsRecPtr->fsPtr != &tclNativeFilesystem) {
		continue;
	    }

	    /*
	     * TODO: Assume that we always find the native file system; it should
	     * always be there...
	     */

	    if (fsRecPtr->fsPtr->normalizePathProc != NULL) {
		startAt = fsRecPtr->fsPtr->normalizePathProc(interp, pathPtr,
			startAt);
	    }
	    break;
	}
    }

    for (fsRecPtr=firstFsRecPtr; fsRecPtr!=NULL; fsRecPtr=fsRecPtr->nextPtr) {

	/*
	 * Skip the native system next time through.
	 */

	if (fsRecPtr->fsPtr == &tclNativeFilesystem) {
	    continue;
	}

	if (fsRecPtr->fsPtr->normalizePathProc != NULL) {
	    startAt = fsRecPtr->fsPtr->normalizePathProc(interp, pathPtr,
		    startAt);
	}

	/*
	 * We could add an efficiency check like this:
	 *		if (retVal == length-of(pathPtr)) {break;}
	 * but there's not much benefit.
	 */
    }
    Disclaim();

    return startAt;
................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * TclGetOpenMode --
 *
 *	This routine is an obsolete, limited version of TclGetOpenModeEx()
 *	below. It exists only to satisfy any extensions imprudently using it
 *	via Tcl's internal stubs table.
 *
 * Results:
 *	Same as TclGetOpenModeEx().
 *
 * Side effects:
 *	Same as TclGetOpenModeEx().
 *
 *---------------------------------------------------------------------------
 */

int
TclGetOpenMode(
    Tcl_Interp *interp,		/* Interpreter to use for error reporting -
				 * may be NULL. */
    const char *modeString,	/* Mode string, e.g. "r+" or "RDONLY CREAT" */
    int *seekFlagPtr)		/* Set this to 1 if the caller should seek to
				 * EOF during the opening of the file. */

{
    int binary = 0;
    return TclGetOpenModeEx(interp, modeString, seekFlagPtr, &binary);
}
 
/*
 *---------------------------------------------------------------------------
 *
 * TclGetOpenModeEx --
 *
 *	Computes a POSIX mode mask for opening a file, from a given string,
 *	and also sets flags to indicate whether the caller should seek to EOF
 *	after opening the file, and whether the caller should configure the
 *	channel for binary data.
 *
 * Results:
 *	On success, returns mode to pass to "open". If an error occurs, the
 *	return value is -1 and if interp is not NULL, sets interp's result
 *	object to an error message.
 *
 * Side effects:
 *	Sets the integer referenced by seekFlagPtr to 1 to tell the caller to
 *	seek to EOF after opening the file, or to 0 otherwise. Sets the

 *	integer referenced by binaryPtr to 1 to tell the caller to seek to
 *	configure the channel for binary data, or to 0 otherwise.
 *



 * Special note:
 *	This code is based on a prototype implementation contributed by Mark
 *	Diekhans.
 *
 *---------------------------------------------------------------------------
 */

int
TclGetOpenModeEx(
    Tcl_Interp *interp,		/* Interpreter to use for error reporting -
				 * may be NULL. */
    const char *modeString,	/* Mode string, e.g. "r+" or "RDONLY CREAT" */
    int *seekFlagPtr,		/* Set this to 1 if the caller should seek to
				 * EOF during the opening of the file. */
    int *binaryPtr)		/* Set this to 1 if the caller should
				 * configure the opened channel for binary
				 * operations. */
{
    int mode, modeArgc, c, i, gotRW;
    const char **modeArgv, *flag;
#define RW_MODES (O_RDONLY|O_WRONLY|O_RDWR)

    /*
     * Check for the simpler fopen-like access modes (e.g., "r"). They are
     * distinguished from the POSIX access modes by the presence of a
     * lower-case first letter.
     */

    *seekFlagPtr = 0;
    *binaryPtr = 0;
    mode = 0;

    /*
     * Guard against international characters before using byte oriented
     * routines.
     */

    if (!(modeString[0] & 0x80)
	    && islower(UCHAR(modeString[0]))) { /* INTL: ISO only. */
	switch (modeString[0]) {
	case 'r':
	    mode = O_RDONLY;
	    break;
	case 'w':
	    mode = O_WRONLY|O_CREAT|O_TRUNC;
	    break;
	case 'a':
	    /*
	     * Added O_APPEND for proper automatic seek-to-end-on-write by the
	     * OS. [Bug 680143]
	     */

	    mode = O_WRONLY|O_CREAT|O_APPEND;
	    *seekFlagPtr = 1;
	    break;
	default:
................................................................................
	while (i<3 && modeString[i]) {
	    if (modeString[i] == modeString[i-1]) {
		goto error;
	    }
	    switch (modeString[i++]) {
	    case '+':
		/*
		 * Must remove the O_APPEND flag so that the seek command
		 * works. [Bug 1773127]
		 */

		mode &= ~(O_RDONLY|O_WRONLY|O_APPEND);
		mode |= O_RDWR;
		break;
	    case 'b':
		*binaryPtr = 1;
................................................................................
	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		    "illegal access mode \"%s\"", modeString));
	}
	return -1;
    }

    /*
     * The access modes are specified using a list of POSIX modes such as
     * O_CREAT.
     *
     * IMPORTANT NOTE: We rely on Tcl_SplitList working correctly when a NULL
     * interpreter is passed in.

     */

    if (Tcl_SplitList(interp, modeString, &modeArgc, &modeArgv) != TCL_OK) {
	if (interp != NULL) {
	    Tcl_AddErrorInfo(interp,
		    "\n    while processing open access modes \"");
	    Tcl_AddErrorInfo(interp, modeString);
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSEvalFile, Tcl_FSEvalFileEx, TclNREvalFile --
 *
 *	Read in a file and process the entire file as one gigantic Tcl

 *	command. Tcl_FSEvalFile is Tcl_FSEvalFileEx without encoding argument.

 *	TclNREvalFile is an NRE-enabled version of Tcl_FSEvalFileEx.
 *
 * Results:
 *	A standard Tcl result, which is either the result of executing the
 *	file or an error indicating why the file couldn't be read.
 *
 * Side effects:
 *	Depends on the commands in the file. During the evaluation of the
 *	contents of the file, iPtr->scriptFile is made to point to pathPtr
 *	(the old value is cached and replaced when this function returns).
 *
 *----------------------------------------------------------------------
 */

int
Tcl_FSEvalFile(
    Tcl_Interp *interp,		/* Interpreter in which to process file. */
    Tcl_Obj *pathPtr)		/* Path of file to process. Tilde-substitution
				 * will be performed on this name. */

{
    return Tcl_FSEvalFileEx(interp, pathPtr, NULL);
}

int
Tcl_FSEvalFileEx(
    Tcl_Interp *interp,		/* Interpreter in which to process file. */
    Tcl_Obj *pathPtr,		/* Path of file to process. Tilde-substitution
				 * will be performed on this name. */

    const char *encodingName)	/* If non-NULL, then use this encoding for the
				 * file. NULL means use the system encoding. */
{
    int length, result = TCL_ERROR;
    Tcl_StatBuf statBuf;
    Tcl_Obj *oldScriptFile;
    Interp *iPtr;
    const char *string;
    Tcl_Channel chan;
................................................................................
	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		"couldn't read file \"%s\": %s",
		Tcl_GetString(pathPtr), Tcl_PosixError(interp)));
	return result;
    }

    /*
     * The eofchar is \32 (^Z). This is the usual on Windows, but we effect
     * this cross-platform to allow for scripted documents. [Bug: 2040]
     */

    Tcl_SetChannelOption(interp, chan, "-eofchar", "\32 {}");

    /*
     * If the encoding is specified, set it for the channel. Else don't touch
     * it (and use the system encoding) Report error on unknown encoding.

     */

    if (encodingName != NULL) {
	if (Tcl_SetChannelOption(interp, chan, "-encoding", encodingName)
		!= TCL_OK) {
	    Tcl_Close(interp,chan);
	    return result;
................................................................................
	}
    }

    objPtr = Tcl_NewObj();
    Tcl_IncrRefCount(objPtr);

    /*
     * Try to read first character of stream, so we can check for utf-8 BOM to
     * be handled especially.
     */

    if (Tcl_ReadChars(chan, objPtr, 1, 0) == TCL_IO_FAILURE) {
	Tcl_Close(interp, chan);
	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		"couldn't read file \"%s\": %s",
		Tcl_GetString(pathPtr), Tcl_PosixError(interp)));
	goto end;
    }
    string = Tcl_GetString(objPtr);

    /*
     * If first character is not a BOM, append the remaining characters,
     * otherwise replace them. [Bug 3466099]
     */

    if (Tcl_ReadChars(chan, objPtr, -1,
	    memcmp(string, "\xef\xbb\xbf", 3)) == TCL_IO_FAILURE) {
	Tcl_Close(interp, chan);
	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		"couldn't read file \"%s\": %s",
................................................................................
    iPtr = (Interp *) interp;
    oldScriptFile = iPtr->scriptFile;
    iPtr->scriptFile = pathPtr;
    Tcl_IncrRefCount(iPtr->scriptFile);
    string = TclGetStringFromObj(objPtr, &length);

    /*
     * TIP #280 Force the evaluator to open a frame for a sourced file.
     */

    iPtr->evalFlags |= TCL_EVAL_FILE;
    result = TclEvalEx(interp, string, length, 0, 1, NULL, string);

    /*
     * Now we have to be careful; the script may have changed the
     * iPtr->scriptFile value, so we must reset it without assuming it still
     * points to 'pathPtr'.
     */

    if (iPtr->scriptFile != NULL) {
	Tcl_DecrRefCount(iPtr->scriptFile);
    }
    iPtr->scriptFile = oldScriptFile;

    if (result == TCL_RETURN) {
	result = TclUpdateReturnInfo(iPtr);
    } else if (result == TCL_ERROR) {
	/*
	 * Record information telling where the error occurred.
	 */

	const char *pathString = TclGetStringFromObj(pathPtr, &length);
	int limit = 150;
	int overflow = (length > limit);

	Tcl_AppendObjToErrorInfo(interp, Tcl_ObjPrintf(
................................................................................
  end:
    Tcl_DecrRefCount(objPtr);
    return result;
}

int
TclNREvalFile(
    Tcl_Interp *interp,		/* Interpreter in which to process file. */
    Tcl_Obj *pathPtr,		/* Path of file to process. Tilde-substitution
				 * will be performed on this name. */

    const char *encodingName)	/* If non-NULL, then use this encoding for the
				 * file. NULL means use the system encoding. */
{
    Tcl_StatBuf statBuf;
    Tcl_Obj *oldScriptFile, *objPtr;
    Interp *iPtr;
    Tcl_Channel chan;
    const char *string;

................................................................................
		"couldn't read file \"%s\": %s",
		Tcl_GetString(pathPtr), Tcl_PosixError(interp)));
	return TCL_ERROR;
    }
    TclPkgFileSeen(interp, Tcl_GetString(pathPtr));

    /*
     * The eofchar is \32 (^Z). This is the usual on Windows, but we effect
     * this cross-platform to allow for scripted documents. [Bug: 2040]
     */

    Tcl_SetChannelOption(interp, chan, "-eofchar", "\32 {}");

    /*
     * If the encoding is specified, set it for the channel. Else don't touch
     * it (and use the system encoding) Report error on unknown encoding.

     */

    if (encodingName != NULL) {
	if (Tcl_SetChannelOption(interp, chan, "-encoding", encodingName)
		!= TCL_OK) {
	    Tcl_Close(interp,chan);
	    return TCL_ERROR;
................................................................................
	}
    }

    objPtr = Tcl_NewObj();
    Tcl_IncrRefCount(objPtr);

    /*
     * Try to read first character of stream, so we can check for utf-8 BOM to
     * be handled especially.
     */

    if (Tcl_ReadChars(chan, objPtr, 1, 0) == TCL_IO_FAILURE) {
	Tcl_Close(interp, chan);
	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		"couldn't read file \"%s\": %s",
		Tcl_GetString(pathPtr), Tcl_PosixError(interp)));
	Tcl_DecrRefCount(objPtr);
	return TCL_ERROR;
    }
    string = Tcl_GetString(objPtr);

    /*
     * If first character is not a BOM, append the remaining characters,
     * otherwise replace them. [Bug 3466099]
     */

    if (Tcl_ReadChars(chan, objPtr, -1,
	    memcmp(string, "\xef\xbb\xbf", 3)) == TCL_IO_FAILURE) {
	Tcl_Close(interp, chan);
	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		"couldn't read file \"%s\": %s",
................................................................................

    iPtr = (Interp *) interp;
    oldScriptFile = iPtr->scriptFile;
    iPtr->scriptFile = pathPtr;
    Tcl_IncrRefCount(iPtr->scriptFile);

    /*
     * TIP #280: Force the evaluator to open a frame for a sourced file.
     */

    iPtr->evalFlags |= TCL_EVAL_FILE;
    TclNRAddCallback(interp, EvalFileCallback, oldScriptFile, pathPtr, objPtr,
	    NULL);
    return TclNREvalObjEx(interp, objPtr, 0, NULL, INT_MIN);
}
................................................................................
{
    Interp *iPtr = (Interp *) interp;
    Tcl_Obj *oldScriptFile = data[0];
    Tcl_Obj *pathPtr = data[1];
    Tcl_Obj *objPtr = data[2];

    /*
     * Now we have to be careful; the script may have changed the
     * iPtr->scriptFile value, so we must reset it without assuming it still
     * points to 'pathPtr'.
     */

    if (iPtr->scriptFile != NULL) {
	Tcl_DecrRefCount(iPtr->scriptFile);
    }
    iPtr->scriptFile = oldScriptFile;

    if (result == TCL_RETURN) {
	result = TclUpdateReturnInfo(iPtr);
    } else if (result == TCL_ERROR) {
	/*
	 * Record information telling where the error occurred.
	 */

	int length;
	const char *pathString = TclGetStringFromObj(pathPtr, &length);
	const int limit = 150;
	int overflow = (length > limit);

................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_GetErrno --
 *
 *	Gets the current value of the Tcl error code variable. This is
 *	currently the global variable "errno" but could in the future change
 *	to something else.
 *
 * Results:
 *	The value of the Tcl error code variable.
 *
 * Side effects:
 *	None. Note that the value of the Tcl error code variable is UNDEFINED
 *	if a call to Tcl_SetErrno did not precede this call.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_GetErrno(void)
{
    /*
     * On some platforms, errno is really a thread local (implemented by the C
     * library).
     */

    return errno;
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_SetErrno --
 *
 *	Sets the Tcl error code variable to the supplied value. On some saner
 *	platforms this is actually a thread-local (this is implemented in the
 *	C library) but this is *really* unsafe to assume!
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Modifies the value of the Tcl error code variable.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_SetErrno(
    int err)			/* The new value. */
{
    /*
     * On some platforms, errno is really a thread local (implemented by the C
     * library).
     */

    errno = err;
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_PosixError --
 *
 *	This function is typically called after UNIX kernel calls return
 *	errors. It stores machine-readable information about the error in
 *	errorCode field of interp and returns an information string for the
 *	caller's use.
 *
 * Results:
 *	The return value is a human-readable string describing the error.
 *
 * Side effects:
 *	The errorCode field of the interp is set.

 *
 *----------------------------------------------------------------------
 */

const char *
Tcl_PosixError(
    Tcl_Interp *interp)		/* Interpreter whose errorCode field is to be
				 * set. */
{
    const char *id, *msg;

    msg = Tcl_ErrnoMsg(errno);
    id = Tcl_ErrnoId();
    if (interp) {
	Tcl_SetErrorCode(interp, "POSIX", id, msg, NULL);
................................................................................
    return msg;
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSStat --

 *
 *	This function replaces the library version of stat and lsat.

 *
 *	The appropriate function for the filesystem to which pathPtr belongs
 *	will be called.
 *
 * Results:
 *	See stat documentation.
 *
 * Side effects:
 *	See stat documentation.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_FSStat(
    Tcl_Obj *pathPtr,		/* Path of file to stat (in current CP). */

    Tcl_StatBuf *buf)		/* Filled with results of stat call. */

{
    const Tcl_Filesystem *fsPtr = Tcl_FSGetFileSystemForPath(pathPtr);

    if (fsPtr != NULL && fsPtr->statProc != NULL) {
	return fsPtr->statProc(pathPtr, buf);
    }
    Tcl_SetErrno(ENOENT);
................................................................................
    return -1;
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSLstat --

 *
 *	This function replaces the library version of lstat. The appropriate
 *	function for the filesystem to which pathPtr belongs will be called.
 *	If no 'lstat' function is listed, but a 'stat' function is, then Tcl
 *	will fall back on the stat function.
 *
 * Results:
 *	See lstat documentation.
 *
 * Side effects:
 *	See lstat documentation.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_FSLstat(
    Tcl_Obj *pathPtr,		/* Path of file to stat (in current CP). */

    Tcl_StatBuf *buf)		/* Filled with results of stat call. */
{
    const Tcl_Filesystem *fsPtr = Tcl_FSGetFileSystemForPath(pathPtr);

    if (fsPtr != NULL) {
	if (fsPtr->lstatProc != NULL) {
	    return fsPtr->lstatProc(pathPtr, buf);
	}
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSAccess --
 *
 *	This function replaces the library version of access. The appropriate
 *	function for the filesystem to which pathPtr belongs will be called.

 *
 * Results:
 *	See access documentation.
 *
 * Side effects:
 *	See access documentation.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_FSAccess(
    Tcl_Obj *pathPtr,		/* Path of file to access (in current CP). */
    int mode)			/* Permission setting. */
{
    const Tcl_Filesystem *fsPtr = Tcl_FSGetFileSystemForPath(pathPtr);

    if (fsPtr != NULL && fsPtr->accessProc != NULL) {
	return fsPtr->accessProc(pathPtr, mode);
    }
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSOpenFileChannel --
 *
 *	The appropriate function for the filesystem to which pathPtr belongs
 *	will be called.
 *
 * Results:
 *	The new channel or NULL, if the named file could not be opened.
 *
 * Side effects:
 *	May open the channel and may cause creation of a file on the file
 *	system.
 *
 *----------------------------------------------------------------------
 */

Tcl_Channel
Tcl_FSOpenFileChannel(
    Tcl_Interp *interp,		/* Interpreter for error reporting; can be
				 * NULL. */
    Tcl_Obj *pathPtr,		/* Name of file to open. */
    const char *modeString,	/* A list of POSIX open modes or a string such
				 * as "rw". */

    int permissions)		/* If the open involves creating a file, with
				 * what modes to create it? */
{
    const Tcl_Filesystem *fsPtr;
    Tcl_Channel retVal = NULL;



    /*
     * We need this just to ensure we return the correct error messages under
     * some circumstances.
     */

    if (Tcl_FSGetNormalizedPath(interp, pathPtr) == NULL) {
	return NULL;
    }

    fsPtr = Tcl_FSGetFileSystemForPath(pathPtr);
    if (fsPtr != NULL && fsPtr->openFileChannelProc != NULL) {
	int mode, seekFlag, binary;

	/*
	 * Parse the mode, picking up whether we want to seek to start with
	 * and/or set the channel automatically into binary mode.
	 */

	mode = TclGetOpenModeEx(interp, modeString, &seekFlag, &binary);
	if (mode == -1) {
	    return NULL;
	}

	/*
	 * Do the actual open() call.
	 */

	retVal = fsPtr->openFileChannelProc(interp, pathPtr, mode,
		permissions);
	if (retVal == NULL) {
	    return NULL;
	}

	/*
	 * Apply appropriate flags parsed out above.
	 */

	if (seekFlag && Tcl_Seek(retVal, (Tcl_WideInt) 0, SEEK_END)
		< (Tcl_WideInt) 0) {
	    if (interp != NULL) {
		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
			"could not seek to end of file while opening \"%s\": %s",
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSUtime --
 *



 *	This function replaces the library version of utime. The appropriate
 *	function for the filesystem to which pathPtr belongs will be called.
 *
 * Results:
 *	See utime documentation.
 *
 * Side effects:
 *	See utime documentation.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_FSUtime(
    Tcl_Obj *pathPtr,		/* File to change access/modification
				 * times. */
    struct utimbuf *tval)	/* Structure containing access/modification
				 * times to use. Should not be modified. */
{
    const Tcl_Filesystem *fsPtr = Tcl_FSGetFileSystemForPath(pathPtr);

    if (fsPtr != NULL && fsPtr->utimeProc != NULL) {
	return fsPtr->utimeProc(pathPtr, tval);
    }
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * NativeFileAttrStrings --
 *
 *	This function implements the platform dependent 'file attributes'
 *	subcommand, for the native filesystem, for listing the set of possible
 *	attribute strings. This function is part of Tcl's native filesystem
 *	support, and is placed here because it is shared by Unix and Windows
 *	code.
 *
 * Results:
 *	An array of strings
 *
 * Side effects:
 *	None.
 *
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * NativeFileAttrsGet --
 *
 *	This function implements the platform dependent 'file attributes'
 *	subcommand, for the native filesystem, for 'get' operations. This
 *	function is part of Tcl's native filesystem support, and is placed
 *	here because it is shared by Unix and Windows code.
 *
 * Results:
 *	Standard Tcl return code. The object placed in objPtrRef (if TCL_OK
 *	was returned) is likely to have a refCount of zero. Either way we must

 *	either store it somewhere (e.g. the Tcl result), or Incr/Decr its
 *	refCount to ensure it is properly freed.


 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
NativeFileAttrsGet(
    Tcl_Interp *interp,		/* The interpreter for error reporting. */
    int index,			/* index of the attribute command. */
    Tcl_Obj *pathPtr,		/* path of file we are operating on. */
    Tcl_Obj **objPtrRef)	/* for output. */
{
    return tclpFileAttrProcs[index].getProc(interp, index, pathPtr,objPtrRef);
}
 
/*
 *----------------------------------------------------------------------
 *
 * NativeFileAttrsSet --
 *
 *	This function implements the platform dependent 'file attributes'
 *	subcommand, for the native filesystem, for 'set' operations. This
 *	function is part of Tcl's native filesystem support, and is placed
 *	here because it is shared by Unix and Windows code.
 *
 * Results:
 *	Standard Tcl return code.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
NativeFileAttrsSet(
    Tcl_Interp *interp,		/* The interpreter for error reporting. */
    int index,			/* index of the attribute command. */
    Tcl_Obj *pathPtr,		/* path of file we are operating on. */
    Tcl_Obj *objPtr)		/* set to this value. */
{
    return tclpFileAttrProcs[index].setProc(interp, index, pathPtr, objPtr);
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSFileAttrStrings --
 *
 *	This function implements part of the hookable 'file attributes'
 *	subcommand. The appropriate function for the filesystem to which
 *	pathPtr belongs will be called.
 *



 * Results:
 *	The called function may either return an array of strings, or may
 *	instead return NULL and place a Tcl list into the given objPtrRef.
 *	Tcl will take that list and first increment its refCount before using
 *	it. On completion of that use, Tcl will decrement its refCount. Hence
 *	if the list should be disposed of by Tcl when done, it should have a
 *	refCount of zero, and if the list should not be disposed of, the
 *	filesystem should ensure it retains a refCount on the object.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * TclFSFileAttrIndex --
 *
 *	Helper function for converting an attribute name to an index into the
 *	attribute table.
 *
 * Results:
 *	Tcl result code, index written to *indexPtr on result==TCL_OK


 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

int
TclFSFileAttrIndex(
    Tcl_Obj *pathPtr,		/* File whose attributes are to be indexed
				 * into. */
    const char *attributeName,	/* The attribute being looked for. */
    int *indexPtr)		/* Where to write the found index. */
{
    Tcl_Obj *listObj = NULL;
    const char *const *attrTable;

    /*
     * Get the attribute table for the file.
     */
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSFileAttrsGet --
 *
 *	This function implements read access for the hookable 'file
 *	attributes' subcommand. The appropriate function for the filesystem to
 *	which pathPtr belongs will be called.
 *
 * Results:
 *	Standard Tcl return code. The object placed in objPtrRef (if TCL_OK
 *	was returned) is likely to have a refCount of zero. Either way we must
 *	either store it somewhere (e.g. the Tcl result), or Incr/Decr its
 *	refCount to ensure it is properly freed.

 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_FSFileAttrsGet(
    Tcl_Interp *interp,		/* The interpreter for error reporting. */
    int index,			/* index of the attribute command. */
    Tcl_Obj *pathPtr,		/* filename we are operating on. */
    Tcl_Obj **objPtrRef)	/* for output. */
{
    const Tcl_Filesystem *fsPtr = Tcl_FSGetFileSystemForPath(pathPtr);

    if (fsPtr != NULL && fsPtr->fileAttrsGetProc != NULL) {
	return fsPtr->fileAttrsGetProc(interp, index, pathPtr, objPtrRef);
    }
    Tcl_SetErrno(ENOENT);
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSFileAttrsSet --
 *
 *	This function implements write access for the hookable 'file
 *	attributes' subcommand. The appropriate function for the filesystem to
 *	which pathPtr belongs will be called.
 *



 * Results:
 *	Standard Tcl return code.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_FSFileAttrsSet(
    Tcl_Interp *interp,		/* The interpreter for error reporting. */
    int index,			/* index of the attribute command. */
    Tcl_Obj *pathPtr,		/* filename we are operating on. */
    Tcl_Obj *objPtr)		/* Input value. */
{
    const Tcl_Filesystem *fsPtr = Tcl_FSGetFileSystemForPath(pathPtr);

    if (fsPtr != NULL && fsPtr->fileAttrsSetProc != NULL) {
	return fsPtr->fileAttrsSetProc(interp, index, pathPtr, objPtr);
    }
    Tcl_SetErrno(ENOENT);
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSGetCwd --
 *
 *	This function replaces the library version of getcwd().
 *
 *	Most VFS's will *not* implement a 'cwdProc'. Tcl now maintains its own
 *	record (in a Tcl_Obj) of the cwd, and an attempt is made to synch this
 *	with the cwd's containing filesystem, if that filesystem provides a
 *	cwdProc (e.g. the native filesystem).
 *
 *	Note that if Tcl's cwd is not in the native filesystem, then of course
 *	Tcl's cwd and the native cwd are different: extensions should
 *	therefore ensure they only access the cwd through this function to
 *	avoid confusion.
 *
 *	If a global cwdPathPtr already exists, it is cached in the thread's
 *	private data structures and reference to the cached copy is returned,
 *	subject to a synchronisation attempt in that cwdPathPtr's fs.
 *
 *	Otherwise, the chain of functions that have been "inserted" into the
 *	filesystem will be called in succession until either a value other
 *	than NULL is returned, or the entire list is visited.
 *
 * Results:
 *	The result is a pointer to a Tcl_Obj specifying the current directory,
 *	or NULL if the current directory could not be determined. If NULL is
 *	returned, an error message is left in the interp's result.


 *
 *	The result already has its refCount incremented for the caller. When
 *	it is no longer needed, that refCount should be decremented.


 *
 * Side effects:
 *	Various objects may be freed and allocated.
 *
 *----------------------------------------------------------------------
 */

................................................................................
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&fsDataKey);

    if (TclFSCwdPointerEquals(NULL)) {
	FilesystemRecord *fsRecPtr;
	Tcl_Obj *retVal = NULL;

	/*
	 * We've never been called before, try to find a cwd. Call each of the
	 * "Tcl_GetCwd" function in succession. A non-NULL return value
	 * indicates the particular function has succeeded.

	 */

	fsRecPtr = FsGetFirstFilesystem();
	Claim();
	for (; (retVal == NULL) && (fsRecPtr != NULL);
		fsRecPtr = fsRecPtr->nextPtr) {
	    ClientData retCd;
................................................................................

	    proc2 = (TclFSGetCwdProc2 *) fsRecPtr->fsPtr->getCwdProc;
	    retCd = proc2(NULL);
	    if (retCd != NULL) {
		Tcl_Obj *norm;

		/*
		 * Looks like a new current directory.
		 */

		retVal = fsRecPtr->fsPtr->internalToNormalizedProc(retCd);
		Tcl_IncrRefCount(retVal);
		norm = TclFSNormalizeAbsolutePath(interp,retVal);
		if (norm != NULL) {
		    /*
		     * We found a cwd, which is now in our global storage. We
		     * must make a copy. Norm already has a refCount of 1.
		     *
		     * Threading issue: note that multiple threads at system
		     * startup could in principle call this function
		     * simultaneously. They will therefore each set the
		     * cwdPathPtr independently. That behaviour is a bit
		     * peculiar, but should be fine. Once we have a cwd, we'll

		     * always be in the 'else' branch below which is simpler.

		     */

		    FsUpdateCwd(norm, retCd);
		    Tcl_DecrRefCount(norm);
		} else {
		    fsRecPtr->fsPtr->freeInternalRepProc(retCd);
		}
................................................................................
		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
			"error getting working directory name: %s",
			Tcl_PosixError(interp)));
	    }
	}
	Disclaim();


	/*
	 * Now the 'cwd' may NOT be normalized, at least on some platforms.


	 * For the sake of efficiency, we want a completely normalized cwd at
	 * all times.
	 *
	 * Finally, if retVal is NULL, we do not have a cwd, which could be
	 * problematic.
	 */

	if (retVal != NULL) {
	    Tcl_Obj *norm = TclFSNormalizeAbsolutePath(interp, retVal);

	    if (norm != NULL) {
		/*
		 * We found a cwd, which is now in our global storage. We must
		 * make a copy. Norm already has a refCount of 1.

		 *
		 * Threading issue: note that multiple threads at system
		 * startup could in principle call this function
		 * simultaneously. They will therefore each set the cwdPathPtr
		 * independently. That behaviour is a bit peculiar, but should
		 * be fine. Once we have a cwd, we'll always be in the 'else'
		 * branch below which is simpler.
		 */

		ClientData cd = (ClientData) Tcl_FSGetNativePath(norm);

		FsUpdateCwd(norm, TclNativeDupInternalRep(cd));
		Tcl_DecrRefCount(norm);
	    }
	    Tcl_DecrRefCount(retVal);





	}
    } else {
	/*
	 * We already have a cwd cached, but we want to give the filesystem it
	 * is in a chance to check whether that cwd has changed, or is perhaps
	 * no longer accessible. This allows an error to be thrown if, say,
	 * the permissions on that directory have changed.

	 */

	const Tcl_Filesystem *fsPtr =
		Tcl_FSGetFileSystemForPath(tsdPtr->cwdPathPtr);
	ClientData retCd = NULL;
	Tcl_Obj *retVal, *norm;


	/*
	 * If the filesystem couldn't be found, or if no cwd function exists
	 * for this filesystem, then we simply assume the cached cwd is ok.
	 * If we do call a cwd, we must watch for errors (if the cwd returns
	 * NULL). This ensures that, say, on Unix if the permissions of the
	 * cwd change, 'pwd' does actually throw the correct error in Tcl.
	 * (This is tested for in the test suite on unix).
	 */

	if (fsPtr == NULL || fsPtr->getCwdProc == NULL) {
	    goto cdDidNotChange;
	}

	if (fsPtr->version == TCL_FILESYSTEM_VERSION_1) {
	    retVal = fsPtr->getCwdProc(interp);
	} else {
	    /*
................................................................................
	     * Looks like a new current directory.
	     */

	    retVal = fsPtr->internalToNormalizedProc(retCd);
	    Tcl_IncrRefCount(retVal);
	}


	/*
	 * Check if the 'cwd' function returned an error; if so, reset the
	 * cwd.



	 */

	if (retVal == NULL) {
	    FsUpdateCwd(NULL, NULL);
	    goto cdDidNotChange;
	}

	/*
	 * Normalize the path.
	 */

	norm = TclFSNormalizeAbsolutePath(interp, retVal);


	/*
	 * Check whether cwd has changed from the value previously stored in
	 * cwdPathPtr. Really 'norm' shouldn't be NULL, but we are careful.
	 */

	if (norm == NULL) {
	    /* Do nothing */
	    if (retCd != NULL) {
		fsPtr->freeInternalRepProc(retCd);
	    }
	} else if (norm == tsdPtr->cwdPathPtr) {
	    goto cdEqual;
	} else {
	    /*

	     * Note that both 'norm' and 'tsdPtr->cwdPathPtr' are normalized
	     * paths. Therefore we can be more efficient than calling

	     * 'Tcl_FSEqualPaths', and in addition avoid a nasty infinite loop
	     * bug when trying to normalize tsdPtr->cwdPathPtr.
	     */

	    int len1, len2;
	    const char *str1, *str2;

	    str1 = TclGetStringFromObj(tsdPtr->cwdPathPtr, &len1);
	    str2 = TclGetStringFromObj(norm, &len2);
	    if ((len1 == len2) && (strcmp(str1, str2) == 0)) {
		/*
		 * If the paths were equal, we can be more efficient and
		 * retain the old path object which will probably already be
		 * shared. In this case we can simply free the normalized path
		 * we just calculated.
		 */

	    cdEqual:
		Tcl_DecrRefCount(norm);
		if (retCd != NULL) {
		    fsPtr->freeInternalRepProc(retCd);
		}
	    } else {




		FsUpdateCwd(norm, retCd);
		Tcl_DecrRefCount(norm);
	    }
	}
	Tcl_DecrRefCount(retVal);
    }

................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSChdir --
 *
 *	This function replaces the library version of chdir().
 *
 *	The path is normalized and then passed to the filesystem which claims
 *	it.
 *
 * Results:
 *	See chdir() documentation. If successful, we keep a record of the
 *	successful path in cwdPathPtr for subsequent calls to getcwd.
 *
 * Side effects:
 *	See chdir() documentation. The global cwdPathPtr may change value.



 *
 *----------------------------------------------------------------------
 */

int
Tcl_FSChdir(
    Tcl_Obj *pathPtr)
................................................................................
	return retVal;
    }

    fsPtr = Tcl_FSGetFileSystemForPath(pathPtr);
    if (fsPtr != NULL) {
	if (fsPtr->chdirProc != NULL) {
	    /*
	     * If this fails, an appropriate errno will have been stored using
	     * 'Tcl_SetErrno()'.
	     */

	    retVal = fsPtr->chdirProc(pathPtr);
	} else {
	    /*
	     * Fallback on stat-based implementation.
	     */

	    Tcl_StatBuf buf;

	    /*
	     * If the file can be stat'ed and is a directory and is readable,
	     * then we can chdir. If any of these actions fail, then
	     * 'Tcl_SetErrno()' should automatically have been called to set
	     * an appropriate error code.
	     */

	    if ((Tcl_FSStat(pathPtr, &buf) == 0) && (S_ISDIR(buf.st_mode))
		    && (Tcl_FSAccess(pathPtr, R_OK) == 0)) {
		/*
		 * We allow the chdir.

		 */

		retVal = 0;




	    }
	}
    } else {
	Tcl_SetErrno(ENOENT);
    }

    /*
     * The cwd changed, or an error was thrown. If an error was thrown, we can
     * just continue (and that will report the error to the user). If there


     * was no error we must assume that the cwd was actually changed to the
     * normalized value we calculated above, and we must therefore cache that
     * information.
     *
     * If the filesystem in question has a getCwdProc, then the correct logic
     * which performs the part below is already part of the Tcl_FSGetCwd()
     * call, so no need to replicate it again. This will have a side effect
     * though. The private authoritative representation of the current working
     * directory stored in cwdPathPtr in static memory will be out-of-sync
     * with the real OS-maintained value. The first call to Tcl_FSGetCwd will
     * however recalculate the private copy to match the OS-value so
     * everything will work right.
     *
     * However, if there is no getCwdProc, then we _must_ update our private
     * storage of the cwd, since this is the only opportunity to do that!
     *
     * Note: We currently call this block of code irrespective of whether
     * there was a getCwdProc or not, but the code should all in principle
     * work if we only call this block if fsPtr->getCwdProc == NULL.
     */

    if (retVal == 0) {
	/*
	 * Note that this normalized path may be different to what we found
	 * above (or at least a different object), if the filesystem epoch
	 * changed recently. This can actually happen with scripted documents
	 * very easily. Therefore we ask for the normalized path again (the



	 * correct value will have been cached as a result of the
	 * Tcl_FSGetFileSystemForPath call above anyway).
	 */

	Tcl_Obj *normDirName = Tcl_FSGetNormalizedPath(NULL, pathPtr);

	if (normDirName == NULL) {
	    /* Not really true, but what else to do? */
	    Tcl_SetErrno(ENOENT);
	    return -1;
	}

	if (fsPtr == &tclNativeFilesystem) {
	    /*
	     * For the native filesystem, we keep a cache of the native
	     * representation of the cwd. But, we want to do that for the
	     * exact format that is returned by 'getcwd' (so that we can later
	     * compare the two representations for equality), which might not
	     * be exactly the same char-string as the native representation of
	     * the fully normalized path (e.g. on Windows there's a
	     * forward-slash vs backslash difference). Hence we ask for this
	     * again here. On Unix it might actually be true that we always
	     * have the correct form in the native rep in which case we could
	     * simply use:
	     *		cd = Tcl_FSGetNativePath(pathPtr);
	     * instead. This should be examined by someone on Unix.
	     */

	    ClientData cd;
	    ClientData oldcd = tsdPtr->cwdClientData;

	    /*
	     * Assumption we are using a filesystem version 2.

	     */

	    TclFSGetCwdProc2 *proc2 = (TclFSGetCwdProc2 *) fsPtr->getCwdProc;

	    cd = proc2(oldcd);
	    if (cd != oldcd) {














		FsUpdateCwd(normDirName, cd);
	    }
	} else {









	    FsUpdateCwd(normDirName, NULL);
	}


	/*
	 * If the filesystem changed between old and new cwd


	 * force filesystem refresh on path objects.
	 */
	if (oldFsPtr != NULL && fsPtr != oldFsPtr) {
	    Tcl_FSMountsChanged(NULL);
	}





    }

    return retVal;
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSLoadFile --
 *
 *	Dynamically loads a binary code file into memory and returns the
 *	addresses of two functions within that file, if they are defined. The
 *	appropriate function for the filesystem to which pathPtr belongs will
 *	be called.
 *
 *	Note that the native filesystem doesn't actually assume 'pathPtr' is a
 *	path. Rather it assumes pathPtr is either a path or just the name
 *	(tail) of a file which can be found somewhere in the environment's
 *	loadable path. This behaviour is not very compatible with virtual
 *	filesystems (and has other problems documented in the load man-page),
 *	so it is advised that full paths are always used.
 *
 * Results:
 *	A standard Tcl completion code. If an error occurs, an error message
 *	is left in the interp's result.

 *
 * Side effects:
 *	New code suddenly appears in memory. This may later be unloaded by
 *	passing the clientData to the unloadProc.


 *
 *----------------------------------------------------------------------
 */

int
Tcl_FSLoadFile(
    Tcl_Interp *interp,		/* Used for error reporting. */
    Tcl_Obj *pathPtr,		/* Name of the file containing the desired
				 * code. */
    const char *sym1, const char *sym2,
				/* Names of two functions to look up in the
				 * file's symbol table. */
    Tcl_PackageInitProc **proc1Ptr, Tcl_PackageInitProc **proc2Ptr,
				/* Where to return the addresses corresponding
				 * to sym1 and sym2. */
    Tcl_LoadHandle *handlePtr,	/* Filled with token for dynamically loaded
				 * file which will be passed back to
				 * (*unloadProcPtr)() to unload the file. */
    Tcl_FSUnloadFileProc **unloadProcPtr)
				/* Filled with address of Tcl_FSUnloadFileProc
				 * function which should be used for this
				 * file. */
{
    const char *symbols[3];
    void *procPtrs[2];
    int res;

    /*
     * Initialize the arrays.
     */

    symbols[0] = sym1;
    symbols[1] = sym2;
    symbols[2] = NULL;

    /*
     * Perform the load.
     */

    res = Tcl_LoadFile(interp, pathPtr, symbols, 0, procPtrs, handlePtr);
    if (res == TCL_OK) {
	*proc1Ptr = (Tcl_PackageInitProc *) procPtrs[0];
	*proc2Ptr = (Tcl_PackageInitProc *) procPtrs[1];
    } else {
	*proc1Ptr = *proc2Ptr = NULL;
    }
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_LoadFile --
 *
 *	Dynamically loads a binary code file into memory and returns the
 *	addresses of a number of given functions within that file, if they are
 *	defined. The appropriate function for the filesystem to which pathPtr
 *	belongs will be called.
 *

 *	Note that the native filesystem doesn't actually assume 'pathPtr' is a
 *	path. Rather it assumes pathPtr is either a path or just the name
 *	(tail) of a file which can be found somewhere in the environment's
 *	loadable path. This behaviour is not very compatible with virtual

 *	filesystems (and has other problems documented in the load man-page),
 *	so it is advised that full paths are always used.
 *
 * Results:
 *	A standard Tcl completion code. If an error occurs, an error message
 *	is left in the interp's result.
 *
 * Side effects:
 *	New code suddenly appears in memory. This may later be unloaded by
 *	calling TclFS_UnloadFile.
 *
 *----------------------------------------------------------------------
 */

/*
 * Workaround for issue with modern HPUX which do allow the unlink (no ETXTBSY
 * error) yet somehow trash some internal data structures which prevents the
 * second and further shared libraries from getting properly loaded. Only the
 * first is ok. We try to get around the issue by not unlinking, i.e.,
 * emulating the behaviour of the older HPUX which denied removal.
 *
 * Doing the unlink is also an issue within docker containers, whose AUFS
 * bungles this as well, see
 *     https://github.com/dotcloud/docker/issues/1911
 *
 * For these situations the change below makes the execution of the unlink
 * semi-controllable at runtime.
 *
 *     An AUFS filesystem (if it can be detected) will force avoidance of
 *     unlink. The env variable TCL_TEMPLOAD_NO_UNLINK allows detection of a
 *     users general request (unlink and not.
 *
 * By default the unlink is done (if not in AUFS). However if the variable is
 * present and set to true (any integer > 0) then the unlink is skipped.
 */

static int
skipUnlink(
    Tcl_Obj *shlibFile)
{
    /*
     * Order of testing:
     * 1. On hpux we generally want to skip unlink in general
     *
     * Outside of hpux then:


     * 2. For a general user request   (TCL_TEMPLOAD_NO_UNLINK present,
     *					non-empty, => int)
     * 3. For general AUFS environment (statfs, if available).
     *
     * Ad 2: This variable can disable/override the AUFS detection, i.e. for
     *	     testing if a newer AUFS does not have the bug any more.

     *
     * Ad 3: This is conditionally compiled in. Condition currently must be
     *	     set manually. This part needs proper tests in the configure(.in).
     */


#ifdef hpux
    return 1;
#else
    char *skipstr = getenv("TCL_TEMPLOAD_NO_UNLINK");

    if (skipstr && (skipstr[0] != '\0')) {
	return atoi(skipstr);
    }

#ifdef TCL_TEMPLOAD_NO_UNLINK



#ifndef NO_FSTATFS
    {
	struct statfs fs;
	/*
	 * Have fstatfs. May not have the AUFS super magic ... Indeed our build
	 * box is too old to have it directly in the headers. Define taken from
	 *     http://mooon.googlecode.com/svn/trunk/linux_include/linux/aufs_type.h
	 *     http://aufs.sourceforge.net/
	 * Better reference will be gladly taken.
	 */
#ifndef AUFS_SUPER_MAGIC



#define AUFS_SUPER_MAGIC ('a' << 24 | 'u' << 16 | 'f' << 8 | 's')
#endif /* AUFS_SUPER_MAGIC */
	if ((statfs(Tcl_GetString(shlibFile), &fs) == 0)
		&& (fs.f_type == AUFS_SUPER_MAGIC)) {
	    return 1;
	}
    }
#endif /* ... NO_FSTATFS */
#endif /* ... TCL_TEMPLOAD_NO_UNLINK */

    /*
     * Fallback: !hpux, no EV override, no AUFS (detection, nor detected):
     * Don't skip
     */
    return 0;
#endif /* hpux */
}

int
Tcl_LoadFile(
    Tcl_Interp *interp,		/* Used for error reporting. */
    Tcl_Obj *pathPtr,		/* Name of the file containing the desired
				 * code. */
    const char *const symbols[],/* Names of functions to look up in the file's
				 * symbol table. */
    int flags,			/* Flags */
    void *procVPtrs,		/* Where to return the addresses corresponding
				 * to symbols[]. */
    Tcl_LoadHandle *handlePtr)	/* Filled with token for shared library
				 * information which can be used in
				 * TclpFindSymbol. */
{
    void **procPtrs = (void **) procVPtrs;
    const Tcl_Filesystem *fsPtr = Tcl_FSGetFileSystemForPath(pathPtr);
    const Tcl_Filesystem *copyFsPtr;
    Tcl_FSUnloadFileProc *unloadProcPtr;
    Tcl_Obj *copyToPtr;
    Tcl_LoadHandle newLoadHandle = NULL;
................................................................................
	}
	if (Tcl_GetErrno() != EXDEV) {
	    return retVal;
	}
    }

    /*
     * The filesystem doesn't support 'load', so we fall back on the following
     * technique:
     *
     * First check if it is readable -- and exists!


     */

    if (Tcl_FSAccess(pathPtr, R_OK) != 0) {
	if (interp) {
	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		    "couldn't load library \"%s\": %s",
		    Tcl_GetString(pathPtr), Tcl_PosixError(interp)));
	}
	return TCL_ERROR;
    }

#ifdef TCL_LOAD_FROM_MEMORY
    /*
     * The platform supports loading code from memory, so ask for a buffer of
     * the appropriate size, read the file into it and load the code from the
     * buffer:
     */

    {
	int ret, size;
	void *buffer;
	Tcl_StatBuf statBuf;
	Tcl_Channel data;
................................................................................
	ret = Tcl_FSStat(pathPtr, &statBuf);
	if (ret < 0) {
	    goto mustCopyToTempAnyway;
	}
	size = (int) statBuf.st_size;

	/*
	 * Tcl_Read takes an int: check that file size isn't wide.
	 */

	if (size != (Tcl_WideInt) statBuf.st_size) {
	    goto mustCopyToTempAnyway;
	}
	data = Tcl_FSOpenFileChannel(interp, pathPtr, "rb", 0666);
	if (!data) {
................................................................................
  mustCopyToTempAnyway:
    if (interp) {
	Tcl_ResetResult(interp);
    }
#endif /* TCL_LOAD_FROM_MEMORY */

    /*
     * Get a temporary filename to use, first to copy the file into, and then
     * to load.
     */

    copyToPtr = TclpTempFileNameForLibrary(interp, pathPtr);
    if (copyToPtr == NULL) {
	return TCL_ERROR;
    }
    Tcl_IncrRefCount(copyToPtr);

    copyFsPtr = Tcl_FSGetFileSystemForPath(copyToPtr);
    if ((copyFsPtr == NULL) || (copyFsPtr == fsPtr)) {
	/*
	 * We already know we can't use Tcl_FSLoadFile from this filesystem,
	 * and we must avoid a possible infinite loop. Try to delete the file




	 * we probably created, and then exit.
	 */

	Tcl_FSDeleteFile(copyToPtr);
	Tcl_DecrRefCount(copyToPtr);
	if (interp) {
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "couldn't load from current filesystem", -1));
	}
	return TCL_ERROR;
    }

    if (TclCrossFilesystemCopy(interp, pathPtr, copyToPtr) != TCL_OK) {
	/*
	 * Cross-platform copy failed.
	 */

	Tcl_FSDeleteFile(copyToPtr);
	Tcl_DecrRefCount(copyToPtr);
	return TCL_ERROR;
    }

#ifndef _WIN32
    /*
     * Do we need to set appropriate permissions on the file? This may be
     * required on some systems. On Unix we could loop over the file
     * attributes, and set any that are called "-permissions" to 0700. However
     * we just do this directly, like this:
     */

    {
	int index;
	Tcl_Obj *perm;

	TclNewLiteralStringObj(perm, "0700");
................................................................................
	    Tcl_FSFileAttrsSet(NULL, index, copyToPtr, perm);
	}
	Tcl_DecrRefCount(perm);
    }
#endif

    /*
     * We need to reset the result now, because the cross-filesystem copy may
     * have stored the number of bytes in the result.
     */

    if (interp) {
	Tcl_ResetResult(interp);
    }

    retVal = Tcl_LoadFile(interp, copyToPtr, symbols, flags, procPtrs,
	    &newLoadHandle);
    if (retVal != TCL_OK) {
	/*
	 * The file didn't load successfully.
	 */

	Tcl_FSDeleteFile(copyToPtr);
	Tcl_DecrRefCount(copyToPtr);
	return retVal;
    }

    /*
     * Try to delete the file immediately - this is possible in some OSes, and
     * avoids any worries about leaving the copy laying around on exit.
     */

    if (!skipUnlink(copyToPtr) &&
	    (Tcl_FSDeleteFile(copyToPtr) == TCL_OK)) {
	Tcl_DecrRefCount(copyToPtr);

	/*
	 * We tell our caller about the real shared library which was loaded.
	 * Note that this does mean that the package list maintained by 'load'

	 * will store the original (vfs) path alongside the temporary load
	 * handle and unload proc ptr.
	 */

	*handlePtr = newLoadHandle;
	if (interp) {
	    Tcl_ResetResult(interp);
	}
	return TCL_OK;
    }

    /*
     * When we unload this file, we need to divert the unloading so we can
     * unload and cleanup the temporary file correctly.
     */

    tvdlPtr = ckalloc(sizeof(FsDivertLoad));

    /*
     * Remember three pieces of information. This allows us to cleanup the
     * diverted load completely, on platforms which allow proper unloading of
     * code.
     */

    tvdlPtr->loadHandle = newLoadHandle;
    tvdlPtr->unloadProcPtr = newUnloadProcPtr;

    if (copyFsPtr != &tclNativeFilesystem) {
	/*
	 * copyToPtr is already incremented for this reference.
	 */

	tvdlPtr->divertedFile = copyToPtr;

	/*
	 * This is the filesystem we loaded it into. Since we have a reference
	 * to 'copyToPtr', we already have a refCount on this filesystem, so
	 * we don't need to worry about it disappearing on us.
	 */

	tvdlPtr->divertedFilesystem = copyFsPtr;
	tvdlPtr->divertedFileNativeRep = NULL;
    } else {
	/*
	 * We need the native rep.
	 */

	tvdlPtr->divertedFileNativeRep = TclNativeDupInternalRep(
		Tcl_FSGetInternalRep(copyToPtr, copyFsPtr));

	/*
	 * We don't need or want references to the copied Tcl_Obj or the
	 * filesystem if it is the native one.
	 */

	tvdlPtr->divertedFile = NULL;
	tvdlPtr->divertedFilesystem = NULL;
	Tcl_DecrRefCount(copyToPtr);
    }

................................................................................
    if (interp) {
	Tcl_ResetResult(interp);
    }
    return retVal;

  resolveSymbols:
    /*
     * At this point, *handlePtr is already set up to the handle for the
     * loaded library. We now try to resolve the symbols.
     */

    if (symbols != NULL) {
	for (i=0 ; symbols[i] != NULL; i++) {
	    procPtrs[i] = Tcl_FindSymbol(interp, *handlePtr, symbols[i]);
	    if (procPtrs[i] == NULL) {
		/*
		 * At least one symbol in the list was not found.  Unload the
		 * file, and report the problem back to the caller.
		 * (Tcl_FindSymbol should already have left an appropriate
		 * error message.)
		 */

		(*handlePtr)->unloadFileProcPtr(*handlePtr);
		*handlePtr = NULL;
		return TCL_ERROR;
	    }
	}
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * DivertFindSymbol --
 *
 *	Find a symbol in a shared library loaded by copy-from-VFS.

 *
 *----------------------------------------------------------------------
 */

static void *
DivertFindSymbol(
    Tcl_Interp *interp, 	/* Tcl interpreter */
    Tcl_LoadHandle loadHandle,	/* Handle to the diverted module */
    const char *symbol)		/* Symbol to resolve */
{
    FsDivertLoad *tvdlPtr = (FsDivertLoad *) loadHandle->clientData;
    Tcl_LoadHandle originalHandle = tvdlPtr->loadHandle;

    return originalHandle->findSymbolProcPtr(interp, originalHandle, symbol);
}
 
/*
 *----------------------------------------------------------------------
 *
 * DivertUnloadFile --
 *
 *	Unloads a file that has been loaded by copying from VFS to the native
 *	filesystem.
 *
 * Parameters:
 *	loadHandle -- Handle of the file to unload
 *
 *----------------------------------------------------------------------
 */

static void
DivertUnloadFile(
    Tcl_LoadHandle loadHandle)
{
    FsDivertLoad *tvdlPtr = (FsDivertLoad *) loadHandle->clientData;
    Tcl_LoadHandle originalHandle;


    /*
     * This test should never trigger, since we give the client data in the
     * function above.
     */

    if (tvdlPtr == NULL) {
	return;
    }
    originalHandle = tvdlPtr->loadHandle;

    /*
     * Call the real 'unloadfile' proc we actually used. It is very important
     * that we call this first, so that the shared library is actually
     * unloaded by the OS. Otherwise, the following 'delete' may well fail
     * because the shared library is still in use.
     */

    originalHandle->unloadFileProcPtr(originalHandle);

    /*
     * What filesystem contains the temp copy of the library?
     */

    if (tvdlPtr->divertedFilesystem == NULL) {
	/*
	 * It was the native filesystem, and we have a special function
	 * available just for this purpose, which we know works even at this
	 * late stage.
	 */

	TclpDeleteFile(tvdlPtr->divertedFileNativeRep);
	NativeFreeInternalRep(tvdlPtr->divertedFileNativeRep);
    } else {
	/*
	 * Remove the temporary file we created. Note, we may crash here
	 * because encodings have been taken down already.
	 */

	if (tvdlPtr->divertedFilesystem->deleteFileProc(tvdlPtr->divertedFile)
		!= TCL_OK) {
	    /*
	     * The above may have failed because the filesystem, or something
	     * it depends upon (e.g. encodings) have been taken down because
	     * Tcl is exiting.
	     *
	     * We may need to work out how to delete this file more robustly
	     * (or give the filesystem the information it needs to delete the
	     * file more robustly).
	     *
	     * In particular, one problem might be that the filesystem cannot
	     * extract the information it needs from the above path object
	     * because Tcl's entire filesystem apparatus (the code in this
	     * file) has been finalized, and it refuses to pass the internal
	     * representation to the filesystem.

	     */
	}

	/*
	 * And free up the allocations. This will also of course remove a
	 * refCount from the Tcl_Filesystem to which this file belongs, which
	 * could then free up the filesystem if we are exiting.
	 */

	Tcl_DecrRefCount(tvdlPtr->divertedFile);
    }

    ckfree(tvdlPtr);
    ckfree(loadHandle);
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FindSymbol --
 *
 *	Find a symbol in a loaded library
 *
 * Results:
 *	Returns a pointer to the symbol if found. If not found, returns NULL
 *	and leaves an error message in the interpreter result.
 *
 * This function was once filesystem-specific, but has been made portable by
 * having TclpDlopen return a structure that includes procedure pointers.
 *
 *----------------------------------------------------------------------
 */

void *
Tcl_FindSymbol(
    Tcl_Interp *interp,		/* Tcl interpreter */
    Tcl_LoadHandle loadHandle,	/* Handle to the loaded library */
    const char *symbol)		/* Name of the symbol to resolve */
{
    return loadHandle->findSymbolProcPtr(interp, loadHandle, symbol);
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSUnloadFile --
 *
 *	Unloads a library given its handle. Checks first that the library
 *	supports unloading.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_FSUnloadFile(
    Tcl_Interp *interp,		/* Tcl interpreter */
    Tcl_LoadHandle handle)	/* Handle of the file to unload */
{
    if (handle->unloadFileProcPtr == NULL) {
	if (interp != NULL) {
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "cannot unload: filesystem does not support unloading",
		    -1));
	}
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * TclFSUnloadTempFile --
 *
 *	This function is called when we loaded a library of code via an
 *	intermediate temporary file. This function ensures the library is
 *	correctly unloaded and the temporary file is correctly deleted.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The effects of the 'unload' function called, and of course the
 *	temporary file will be deleted.
 *
 *----------------------------------------------------------------------
 */

void
TclFSUnloadTempFile(
    Tcl_LoadHandle loadHandle)	/* loadHandle returned by a previous call to
				 * Tcl_FSLoadFile(). The loadHandle is a token
				 * that represents the loaded file. */
{
    FsDivertLoad *tvdlPtr = (FsDivertLoad *) loadHandle;


    /*
     * This test should never trigger, since we give the client data in the
     * function above.
     */

    if (tvdlPtr == NULL) {
	return;
    }


    /*
     * Call the real 'unloadfile' proc we actually used. It is very important
     * that we call this first, so that the shared library is actually
     * unloaded by the OS. Otherwise, the following 'delete' may well fail
     * because the shared library is still in use.
     */

    if (tvdlPtr->unloadProcPtr != NULL) {
	tvdlPtr->unloadProcPtr(tvdlPtr->loadHandle);
    }

    if (tvdlPtr->divertedFilesystem == NULL) {
	/*
	 * It was the native filesystem, and we have a special function
	 * available just for this purpose, which we know works even at this
	 * late stage.
	 */

	TclpDeleteFile(tvdlPtr->divertedFileNativeRep);
	NativeFreeInternalRep(tvdlPtr->divertedFileNativeRep);
    } else {
	/*
	 * Remove the temporary file we created. Note, we may crash here
	 * because encodings have been taken down already.

	 */

	if (tvdlPtr->divertedFilesystem->deleteFileProc(tvdlPtr->divertedFile)
		!= TCL_OK) {
	    /*
	     * The above may have failed because the filesystem, or something
	     * it depends upon (e.g. encodings) have been taken down because
	     * Tcl is exiting.
	     *
	     * We may need to work out how to delete this file more robustly
	     * (or give the filesystem the information it needs to delete the
	     * file more robustly).
	     *
	     * In particular, one problem might be that the filesystem cannot
	     * extract the information it needs from the above path object
	     * because Tcl's entire filesystem apparatus (the code in this
	     * file) has been finalized, and it refuses to pass the internal
	     * representation to the filesystem.

	     */
	}

	/*
	 * And free up the allocations. This will also of course remove a
	 * refCount from the Tcl_Filesystem to which this file belongs, which
	 * could then free up the filesystem if we are exiting.
	 */

	Tcl_DecrRefCount(tvdlPtr->divertedFile);
    }

    ckfree(tvdlPtr);
}
 
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSLink --
 *

 *	This function replaces the library version of readlink() and can also
 *	be used to make links. The appropriate function for the filesystem to
 *	which pathPtr belongs will be called.
 *
 * Results:
 *	If toPtr is NULL, then the result is a Tcl_Obj specifying the contents
 *	of the symbolic link given by 'pathPtr', or NULL if the symbolic link
 *	could not be read. The result is owned by the caller, which should
 *	call Tcl_DecrRefCount when the result is no longer needed.
 *
 *	If toPtr is non-NULL, then the result is toPtr if the link action was
 *	successful, or NULL if not. In this case the result has no additional
 *	reference count, and need not be freed. The actual action to perform
 *	is given by the 'linkAction' flags, which is an or'd combination of:

 *
 *		TCL_CREATE_SYMBOLIC_LINK
 *		TCL_CREATE_HARD_LINK
 *
 *	Note that most filesystems will not support linking across to
 *	different filesystems, so this function will usually fail unless toPtr

 *	is in the same FS as pathPtr.
 *
 * Side effects:


 *	See readlink() documentation. A new filesystem link object may appear.
 *
 *---------------------------------------------------------------------------
 */

Tcl_Obj *
Tcl_FSLink(
    Tcl_Obj *pathPtr,		/* Path of file to readlink or link. */
    Tcl_Obj *toPtr,		/* NULL or path to be linked to. */


    int linkAction)		/* Action to perform. */
{
    const Tcl_Filesystem *fsPtr = Tcl_FSGetFileSystemForPath(pathPtr);

    if (fsPtr != NULL && fsPtr->linkProc != NULL) {
	return fsPtr->linkProc(pathPtr, toPtr, linkAction);
    }

    /*
     * If S_IFLNK isn't defined it means that the machine doesn't support
     * symbolic links, so the file can't possibly be a symbolic link. Generate
     * an EINVAL error, which is what happens on machines that do support
     * symbolic links when you invoke readlink on a file that isn't a symbolic
     * link.
     */

#ifndef S_IFLNK
    errno = EINVAL; /* TODO: Change to Tcl_SetErrno()? */
#else
    Tcl_SetErrno(ENOENT);
#endif /* S_IFLNK */
................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSListVolumes --
 *
 *	Lists the currently mounted volumes. The chain of functions that have
 *	been "inserted" into the filesystem will be called in succession; each
 *	may return a list of volumes, all of which are added to the result
 *	until all mounted file systems are listed.
 *
 *	Notice that we assume the lists returned by each filesystem (if non
 *	NULL) have been given a refCount for us already. However, we are NOT
 *	allowed to hang on to the list itself (it belongs to the filesystem we
 *	called). Therefore we quite naturally add its contents to the result
 *	we are building, and then decrement the refCount.
 *
 * Results:
 *	The list of volumes, in an object which has refCount 0.
 *
 * Side effects:
 *	None
 *
................................................................................
Tcl_Obj *
Tcl_FSListVolumes(void)
{
    FilesystemRecord *fsRecPtr;
    Tcl_Obj *resultPtr = Tcl_NewObj();

    /*
     * Call each of the "listVolumes" function in succession. A non-NULL
     * return value indicates the particular function has succeeded. We call
     * all the functions registered, since we want a list of all drives from
     * all filesystems.
     */

    fsRecPtr = FsGetFirstFilesystem();
    Claim();
    while (fsRecPtr != NULL) {
	if (fsRecPtr->fsPtr->listVolumesProc != NULL) {
	    Tcl_Obj *thisFsVolumes = fsRecPtr->fsPtr->listVolumesProc();

	    if (thisFsVolumes != NULL) {
		Tcl_ListObjAppendList(NULL, resultPtr, thisFsVolumes);




		Tcl_DecrRefCount(thisFsVolumes);
	    }
	}
	fsRecPtr = fsRecPtr->nextPtr;
    }
    Disclaim();

................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * FsListMounts --
 *
 *	List all mounts within the given directory, which match the given
 *	pattern.
 *
 * Results:

 *	The list of mounts, in a list object which has refCount 0, or NULL if
 *	we didn't even find any filesystems to try to list mounts.
 *
 * Side effects:
 *	None
 *
 *---------------------------------------------------------------------------
 */

static Tcl_Obj *
FsListMounts(
    Tcl_Obj *pathPtr,		/* Contains path to directory to search. */
    const char *pattern)	/* Pattern to match against. */
{
    FilesystemRecord *fsRecPtr;
    Tcl_GlobTypeData mountsOnly = { TCL_GLOB_TYPE_MOUNT, 0, NULL, NULL };
    Tcl_Obj *resultPtr = NULL;

    /*
     * Call each of the "matchInDirectory" functions in succession, with the
     * specific type information 'mountsOnly'. A non-NULL return value
     * indicates the particular function has succeeded. We call all the
     * functions registered, since we want a list from each filesystems.
     */

    fsRecPtr = FsGetFirstFilesystem();
    Claim();
    while (fsRecPtr != NULL) {
	if (fsRecPtr->fsPtr != &tclNativeFilesystem &&
		fsRecPtr->fsPtr->matchInDirectoryProc != NULL) {
................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSSplitPath --
 *
 *	This function takes the given Tcl_Obj, which should be a valid path,
 *	and returns a Tcl List object containing each segment of that path as
 *	an element.
 *
 * Results:
 *	Returns list object with refCount of zero. If the passed in lenPtr is
 *	non-NULL, we use it to return the number of elements in the returned
 *	list.
 *
 * Side effects:
 *	None.

 *
 *---------------------------------------------------------------------------
 */

Tcl_Obj *
Tcl_FSSplitPath(
    Tcl_Obj *pathPtr,		/* Path to split. */

    int *lenPtr)		/* int to store number of path elements. */
{
    Tcl_Obj *result = NULL;	/* Needed only to prevent gcc warnings. */
    const Tcl_Filesystem *fsPtr;
    char separator = '/';
    int driveNameLength;
    const char *p;

    /*
     * Perform platform specific splitting.
     */

    if (TclFSGetPathType(pathPtr, &fsPtr,
	    &driveNameLength) == TCL_PATH_ABSOLUTE) {
	if (fsPtr == &tclNativeFilesystem) {
	    return TclpNativeSplitPath(pathPtr, lenPtr);
	}
    } else {
	return TclpNativeSplitPath(pathPtr, lenPtr);
    }

    /*
     * We assume separators are single characters.
     */

    if (fsPtr->filesystemSeparatorProc != NULL) {
	Tcl_Obj *sep = fsPtr->filesystemSeparatorProc(pathPtr);

	if (sep != NULL) {
	    Tcl_IncrRefCount(sep);
	    separator = Tcl_GetString(sep)[0];
	    Tcl_DecrRefCount(sep);
	}
    }

    /*
     * Place the drive name as first element of the result list. The drive
     * name may contain strange characters, like colons and multiple forward
     * slashes (for example 'ftp://' is a valid vfs drive name)
     */

    result = Tcl_NewObj();
    p = Tcl_GetString(pathPtr);
    Tcl_ListObjAppendElement(NULL, result,
	    Tcl_NewStringObj(p, driveNameLength));
    p += driveNameLength;

    /*
     * Add the remaining path elements to the list.
     */

    for (;;) {
	const char *elementStart = p;
	int length;

	while ((*p != '\0') && (*p != separator)) {
................................................................................
	    Tcl_ListObjAppendElement(NULL, result, nextElt);
	}
	if (*p++ == '\0') {
	    break;
	}
    }

    /*
     * Compute the number of elements in the result.
     */

    if (lenPtr != NULL) {
	TclListObjLength(NULL, result, lenPtr);
    }
    return result;
}
/*
 *----------------------------------------------------------------------
 *
 * TclGetPathType --
 *
 *	Helper function used by FSGetPathType.
 *
 * Results:
 *	Returns one of TCL_PATH_ABSOLUTE, TCL_PATH_RELATIVE, or
 *	TCL_PATH_VOLUME_RELATIVE. The filesystem reference will be set if and
 *	only if it is non-NULL and the function's return value is
 *	TCL_PATH_ABSOLUTE.
 *
 * Side effects:
 *	None.

 *
 *----------------------------------------------------------------------
 */

Tcl_PathType
TclGetPathType(
    Tcl_Obj *pathPtr,		/* Path to determine type for. */
    const Tcl_Filesystem **filesystemPtrPtr,
				/* If absolute path and this is not NULL, then
				 * set to the filesystem which claims this
				 * path. */
    int *driveNameLengthPtr,	/* If the path is absolute, and this is
				 * non-NULL, then set to the length of the
				 * driveName. */
    Tcl_Obj **driveNameRef)	/* If the path is absolute, and this is

				 * non-NULL, then set to the name of the
				 * drive, network-volume which contains the
				 * path, already with a refCount for the
				 * caller. */
{
    int pathLen;
    const char *path = TclGetStringFromObj(pathPtr, &pathLen);
    Tcl_PathType type;

    type = TclFSNonnativePathType(path, pathLen, filesystemPtrPtr,
	    driveNameLengthPtr, driveNameRef);
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * TclFSNonnativePathType --
 *
 *	Helper function used by TclGetPathType. Its purpose is to check
 *	whether the given path starts with a string which corresponds to a
 *	file volume in any registered filesystem except the native one. For
 *	speed and historical reasons the native filesystem has special
 *	hard-coded checks dotted here and there in the filesystem code.
 *
 * Results:
 *	Returns one of TCL_PATH_ABSOLUTE or TCL_PATH_RELATIVE. The filesystem
 *	reference will be set if and only if it is non-NULL and the function's
 *	return value is TCL_PATH_ABSOLUTE.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

Tcl_PathType
TclFSNonnativePathType(
    const char *path,		/* Path to determine type for. */
    int pathLen,		/* Length of the path. */
    const Tcl_Filesystem **filesystemPtrPtr,
				/* If absolute path and this is not NULL, then
				 * set to the filesystem which claims this
				 * path. */
    int *driveNameLengthPtr,	/* If the path is absolute, and this is
				 * non-NULL, then set to the length of the
				 * driveName. */
    Tcl_Obj **driveNameRef)	/* If the path is absolute, and this is
				 * non-NULL, then set to the name of the
				 * drive, network-volume which contains the
				 * path, already with a refCount for the
				 * caller. */
{
    FilesystemRecord *fsRecPtr;
    Tcl_PathType type = TCL_PATH_RELATIVE;

    /*
     * Call each of the "listVolumes" function in succession, checking whether
     * the given path is an absolute path on any of the volumes returned (this
     * is done by checking whether the path's prefix matches).
     */

    fsRecPtr = FsGetFirstFilesystem();
    Claim();
    while (fsRecPtr != NULL) {
	/*
	 * We want to skip the native filesystem in this loop because
	 * otherwise we won't necessarily pass all the Tcl testsuite - this is
	 * because some of the tests artificially change the current platform
	 * (between win, unix) but the list of volumes we get by calling
	 * fsRecPtr->fsPtr->listVolumesProc will reflect the current (real)
	 * platform only and this may cause some tests to fail. In particular,
	 * on Unix '/' will match the beginning of certain absolute Windows
	 * paths starting '//' and those tests will go wrong.
	 *
	 * Besides these test-suite issues, there is one other reason to skip

	 * the native filesystem - since the tclFilename.c code has nice fast
	 * 'absolute path' checkers, we don't want to waste time repeating
	 * that effort here, and this function is actually called quite often,

	 * so if we can save the overhead of the native filesystem returning
	 * us a list of volumes all the time, it is better.

	 */

	if ((fsRecPtr->fsPtr != &tclNativeFilesystem)
		&& (fsRecPtr->fsPtr->listVolumesProc != NULL)) {
	    int numVolumes;
	    Tcl_Obj *thisFsVolumes = fsRecPtr->fsPtr->listVolumesProc();

	    if (thisFsVolumes != NULL) {
		if (Tcl_ListObjLength(NULL, thisFsVolumes, &numVolumes)
			!= TCL_OK) {
		    /*
		     * This is VERY bad; the listVolumesProc didn't return a
		     * valid list. Set numVolumes to -1 so that we skip the
		     * while loop below and just return with the current value
		     * of 'type'.
		     *
		     * It would be better if we could signal an error here
		     * (but Tcl_Panic seems a bit excessive).
		     */

		    numVolumes = -1;
		}
		while (numVolumes > 0) {
		    Tcl_Obj *vol;
		    int len;
................................................................................
			}
			break;
		    }
		}
		Tcl_DecrRefCount(thisFsVolumes);
		if (type == TCL_PATH_ABSOLUTE) {
		    /*
		     * We don't need to examine any more filesystems.
		     */

		    break;
		}
	    }
	}
	fsRecPtr = fsRecPtr->nextPtr;
................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSRenameFile --
 *
 *	If the two paths given belong to the same filesystem, we call that
 *	filesystems rename function. Otherwise we simply return the POSIX
 *	error 'EXDEV', and -1.
 *
 * Results:
 *	Standard Tcl error code if a function was called.

 *
 * Side effects:
 *	A file may be renamed.
 *
 *---------------------------------------------------------------------------
 */

int
Tcl_FSRenameFile(
    Tcl_Obj *srcPathPtr,	/* Pathname of file or dir to be renamed
				 * (UTF-8). */
    Tcl_Obj *destPathPtr)	/* New pathname of file or directory
				 * (UTF-8). */
{
    int retVal = -1;
    const Tcl_Filesystem *fsPtr, *fsPtr2;

    fsPtr = Tcl_FSGetFileSystemForPath(srcPathPtr);
    fsPtr2 = Tcl_FSGetFileSystemForPath(destPathPtr);

................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSCopyFile --
 *
 *	If the two paths given belong to the same filesystem, we call that
 *	filesystem's copy function. Otherwise we simply return the POSIX error
 *	'EXDEV', and -1.
 *
 *	Note that in the native filesystems, 'copyFileProc' is defined to copy
 *	soft links (i.e. it copies the links themselves, not the things they
 *	point to).

 *
 * Results:
 *	Standard Tcl error code if a function was called.


 *
 * Side effects:

 *	A file may be copied.
 *
 *---------------------------------------------------------------------------
 */

int
Tcl_FSCopyFile(
    Tcl_Obj *srcPathPtr,	/* Pathname of file to be copied (UTF-8). */
    Tcl_Obj *destPathPtr)	/* Pathname of file to copy to (UTF-8). */
{
    int retVal = -1;
    const Tcl_Filesystem *fsPtr, *fsPtr2;

    fsPtr = Tcl_FSGetFileSystemForPath(srcPathPtr);
    fsPtr2 = Tcl_FSGetFileSystemForPath(destPathPtr);

................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * TclCrossFilesystemCopy --
 *
 *	Helper for above function, and for Tcl_FSLoadFile, to copy files from
 *	one filesystem to another. This function will overwrite the target
 *	file if it already exists.
 *
 * Results:
 *	Standard Tcl error code.
 *
 * Side effects:
 *	A file may be created.
 *
 *---------------------------------------------------------------------------
 */

int
TclCrossFilesystemCopy(
    Tcl_Interp *interp,		/* For error messages. */
    Tcl_Obj *source,		/* Pathname of file to be copied (UTF-8). */
    Tcl_Obj *target)		/* Pathname of file to copy to (UTF-8). */
{
    int result = TCL_ERROR;
    int prot = 0666;
    Tcl_Channel in, out;
    Tcl_StatBuf sourceStatBuf;
    struct utimbuf tval;

    out = Tcl_FSOpenFileChannel(interp, target, "wb", prot);
    if (out == NULL) {
	/*
	 * It looks like we cannot copy it over. Bail out...
	 */
	goto done;
    }

    in = Tcl_FSOpenFileChannel(interp, source, "rb", prot);
    if (in == NULL) {
	/*
	 * This is very strange, caller should have checked this...
	 */

	Tcl_Close(interp, out);
	goto done;
    }

    /*
     * Copy it synchronously. We might wish to add an asynchronous option to
     * support vfs's which are slow (e.g. network sockets).
     */

    if (TclCopyChannel(interp, in, out, -1, NULL) == TCL_OK) {
	result = TCL_OK;
    }

    /*
     * If the copy failed, assume that copy channel left a good error message.
     */

    Tcl_Close(interp, in);
    Tcl_Close(interp, out);

    /*
     * Set modification date of copied file.
................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSDeleteFile --
 *
 *	The appropriate function for the filesystem to which pathPtr belongs
 *	will be called.
 *
 * Results:
 *	Standard Tcl error code.
 *
 * Side effects:
 *	A file may be deleted.
 *
 *---------------------------------------------------------------------------
 */

................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSCreateDirectory --
 *
 *	The appropriate function for the filesystem to which pathPtr belongs
 *	will be called.
 *
 * Results:
 *	Standard Tcl error code.
 *
 * Side effects:
 *	A directory may be created.

 *
 *---------------------------------------------------------------------------
 */

int
Tcl_FSCreateDirectory(
    Tcl_Obj *pathPtr)		/* Pathname of directory to create (UTF-8). */
................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSCopyDirectory --
 *
 *	If the two paths given belong to the same filesystem, we call that
 *	filesystems copy-directory function. Otherwise we simply return the
 *	POSIX error 'EXDEV', and -1.
 *
 * Results:
 *	Standard Tcl error code if a function was called.

 *
 * Side effects:
 *	A directory may be copied.

 *
 *---------------------------------------------------------------------------
 */

int
Tcl_FSCopyDirectory(
    Tcl_Obj *srcPathPtr,	/* Pathname of directory to be copied
				 * (UTF-8). */

    Tcl_Obj *destPathPtr,	/* Pathname of target directory (UTF-8). */
    Tcl_Obj **errorPtr)		/* If non-NULL, then will be set to a new
				 * object containing name of file causing
				 * error, with refCount 1. */



{
    int retVal = -1;
    const Tcl_Filesystem *fsPtr, *fsPtr2;

    fsPtr = Tcl_FSGetFileSystemForPath(srcPathPtr);
    fsPtr2 = Tcl_FSGetFileSystemForPath(destPathPtr);

................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSRemoveDirectory --
 *
 *	The appropriate function for the filesystem to which pathPtr belongs
 *	will be called.
 *
 * Results:
 *	Standard Tcl error code.
 *
 * Side effects:
 *	A directory may be deleted.

 *
 *---------------------------------------------------------------------------
 */

int
Tcl_FSRemoveDirectory(
    Tcl_Obj *pathPtr,		/* Pathname of directory to be removed
				 * (UTF-8). */
    int recursive,		/* If non-zero, removes directories that are
				 * nonempty. Otherwise, will only remove empty
				 * directories. */
    Tcl_Obj **errorPtr)		/* If non-NULL, then will be set to a new
				 * object containing name of file causing
				 * error, with refCount 1. */


{
    const Tcl_Filesystem *fsPtr = Tcl_FSGetFileSystemForPath(pathPtr);

    if (fsPtr == NULL || fsPtr->removeDirectoryProc == NULL) {
	Tcl_SetErrno(ENOENT);
	return -1;
    }

    /*
     * When working recursively, we check whether the cwd lies inside this
     * directory and move it if it does.
     */

    if (recursive) {
	Tcl_Obj *cwdPtr = Tcl_FSGetCwd(NULL);

	if (cwdPtr != NULL) {
	    const char *cwdStr, *normPathStr;
	    int cwdLen, normLen;
	    Tcl_Obj *normPath = Tcl_FSGetNormalizedPath(NULL, pathPtr);

	    if (normPath != NULL) {
		normPathStr = TclGetStringFromObj(normPath, &normLen);
		cwdStr = TclGetStringFromObj(cwdPtr, &cwdLen);
		if ((cwdLen >= normLen) && (strncmp(normPathStr, cwdStr,
			(size_t) normLen) == 0)) {
		    /*
		     * The cwd is inside the directory, so we perform a 'cd
		     * [file dirname $path]'.
		     */

		    Tcl_Obj *dirPtr = TclPathPart(NULL, pathPtr,
			    TCL_PATH_DIRNAME);

		    Tcl_FSChdir(dirPtr);
		    Tcl_DecrRefCount(dirPtr);
................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSGetFileSystemForPath --
 *
 *	This function determines which filesystem to use for a particular path
 *	object, and returns the filesystem which accepts this file. If no
 *	filesystem will accept this object as a valid file path, then NULL is
 *	returned.
 *
 * Results:
 *	NULL or a filesystem which will accept this path.

 *
 * Side effects:
 *	The object may be converted to a path type.


 *
 *---------------------------------------------------------------------------
 */

const Tcl_Filesystem *
Tcl_FSGetFileSystemForPath(
    Tcl_Obj *pathPtr)
................................................................................
    const Tcl_Filesystem *retVal = NULL;

    if (pathPtr == NULL) {
	Tcl_Panic("Tcl_FSGetFileSystemForPath called with NULL object");
	return NULL;
    }


    /*
     * If the object has a refCount of zero, we reject it. This is to avoid
     * possible segfaults or nondeterministic memory leaks (i.e. the user
     * doesn't know if they should decrement the ref count on return or not).
     */

    if (pathPtr->refCount == 0) {
	Tcl_Panic("Tcl_FSGetFileSystemForPath called with object with refCount == 0");
	return NULL;
    }

    /*
     * Check if the filesystem has changed in some way since this object's
     * internal representation was calculated. Before doing that, assure we
     * have the most up-to-date copy of the master filesystem. This is
     * accomplished by the FsGetFirstFilesystem() call.
     */

    fsRecPtr = FsGetFirstFilesystem();
    Claim();




    if (TclFSEnsureEpochOk(pathPtr, &retVal) != TCL_OK) {

	Disclaim();
	return NULL;
    } else if (retVal != NULL) {
	/* TODO: Can this happen? */


	Disclaim();
	return retVal;
    }

    /*
     * Call each of the "pathInFilesystem" functions in succession. A
     * non-return value of -1 indicates the particular function has succeeded.
     */

    for (; fsRecPtr!=NULL ; fsRecPtr=fsRecPtr->nextPtr) {
	ClientData clientData = NULL;

	if (fsRecPtr->fsPtr->pathInFilesystemProc == NULL) {
	    continue;
	}

	if (fsRecPtr->fsPtr->pathInFilesystemProc(pathPtr, &clientData)!=-1) {
	    /*
	     * We assume the type of pathPtr hasn't been changed by the above
	     * call to the pathInFilesystemProc.
	     */

	    TclFSSetPathDetails(pathPtr, fsRecPtr->fsPtr, clientData);
	    Disclaim();
	    return fsRecPtr->fsPtr;
	}
    }
    Disclaim();
................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSGetNativePath --
 *
 *	This function is for use by the Win/Unix native filesystems, so that
 *	they can easily retrieve the native (char* or WCHAR*) representation
 *	of a path. Other filesystems will probably want to implement similar
 *	functions. They basically act as a safety net around
 *	Tcl_FSGetInternalRep. Normally your file-system functions will always
 *	be called with path objects already converted to the correct
 *	filesystem, but if for some reason they are called directly (i.e. by
 *	functions not in this file), then one cannot necessarily guarantee
 *	that the path object pointer is from the correct filesystem.
 *
 *	Note: in the future it might be desirable to have separate versions
 *	of this function with different signatures, for example
 *	Tcl_FSGetNativeWinPath, Tcl_FSGetNativeUnixPath etc. Right now, since
 *	native paths are all string based, we use just one function.
 *
 * Results:
 *	NULL or a valid native path.
 *
 * Side effects:
 *	See Tcl_FSGetInternalRep.
 *
 *---------------------------------------------------------------------------
 */

const void *
Tcl_FSGetNativePath(
    Tcl_Obj *pathPtr)
................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * NativeFreeInternalRep --
 *
 *	Free a native internal representation, which will be non-NULL.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Memory is released.
 *
................................................................................
    ckfree(clientData);
}
 
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSFileSystemInfo --

 *
 *	This function returns a list of two elements. The first element is the
 *	name of the filesystem (e.g. "native" or "vfs"), and the second is the
 *	particular type of the given path within that filesystem.
 *
 * Results:


 *	A list of two elements.
 *
 * Side effects:
 *	The object may be converted to a path type.

 *
 *---------------------------------------------------------------------------
 */

Tcl_Obj *
Tcl_FSFileSystemInfo(
    Tcl_Obj *pathPtr)
................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSPathSeparator --
 *
 *	This function returns the separator to be used for a given path. The
 *	object returned should have a refCount of zero
 *
 * Results:
 *	A Tcl object, with a refCount of zero. If the caller needs to retain a
 *	reference to the object, it should call Tcl_IncrRefCount, and should
 *	otherwise free the object.

 *
 * Side effects:
 *	The path object may be converted to a path type.
 *
 *---------------------------------------------------------------------------
 */

Tcl_Obj *
Tcl_FSPathSeparator(
    Tcl_Obj *pathPtr)
................................................................................
    }

    if (fsPtr->filesystemSeparatorProc != NULL) {
	return fsPtr->filesystemSeparatorProc(pathPtr);
    }

    /*
     * Allow filesystems not to provide a filesystemSeparatorProc if they wish
     * to use the standard forward slash.
     */

    TclNewLiteralStringObj(resultObj, "/");
    return resultObj;
}
 
/*
 *---------------------------------------------------------------------------
 *
 * NativeFilesystemSeparator --
 *
 *	This function is part of the native filesystem support, and returns
 *	the separator for the given path.
 *
 * Results:
 *	String object containing the separator character.
 *
 * Side effects:
 *	None.
 *
 *---------------------------------------------------------------------------
 */

/*
 * tclIOUtil.c --
 *
 *	Provides an interface for managing filesystems in Tcl, and also for
 *	creating a filesystem interface in Tcl arbitrary facilities.  All
 *	filesystem operations are performed via this interface.  Vince Darley
 *	is the primary author.  Other signifiant contributors are Karl



 *	Lehenbauer, Mark Diekhans and Peter da Silva.
 *
 * Copyright (c) 1991-1994 The Regents of the University of California.
 * Copyright (c) 1994-1997 Sun Microsystems, Inc.
 * Copyright (c) 2001-2004 Vincent Darley.
 *
 * See the file "license.terms" for information on usage and redistribution of
 * this file, and for a DISCLAIMER OF ALL WARRANTIES.
................................................................................
#include <sys/statfs.h>
#endif
#endif

/*
 * struct FilesystemRecord --
 *
 * An item in a linked list of registered filesystems

 */

typedef struct FilesystemRecord {
    ClientData clientData;	/* Client-specific data for the filesystem
				 * (can be NULL) */
    const Tcl_Filesystem *fsPtr;/* Pointer to filesystem dispatch table. */
    struct FilesystemRecord *nextPtr;
				/* The next registered filesystem, or NULL to
				 * indicate the end of the list. */
    struct FilesystemRecord *prevPtr;
				/* The previous filesystem, or NULL to indicate
				 * the ned of the list */
} FilesystemRecord;

/*





 */

typedef struct {
    int initialized;
    size_t cwdPathEpoch;	/* Compared with the global cwdPathEpoch to
				 * determine whether cwdPathPtr is stale.
				 */
    size_t filesystemEpoch;
    Tcl_Obj *cwdPathPtr;	/* A private copy of cwdPathPtr. Updated when
				 * the value is accessed  and cwdPathEpoch has
				 * changed.
				 */
    ClientData cwdClientData;
    FilesystemRecord *filesystemList;
    size_t claims;
} ThreadSpecificData;

/*
 * Forward declarations.
 */

static Tcl_NRPostProc	EvalFileCallback;
static FilesystemRecord*FsGetFirstFilesystem(void);
static void		FsThrExitProc(ClientData cd);
static Tcl_Obj *	FsListMounts(Tcl_Obj *pathPtr, const char *pattern);
static void		FsAddMountsToGlobResult(Tcl_Obj *resultPtr,
................................................................................
static void		Claim(void);
static void		Disclaim(void);

static void *		DivertFindSymbol(Tcl_Interp *interp,
			    Tcl_LoadHandle loadHandle, const char *symbol);
static void		DivertUnloadFile(Tcl_LoadHandle loadHandle);







 



/*
 * Functions that provide native filesystem support. They are private and


 * should be used only here.  They should be called instead of calling Tclp...
 * native filesystem functions.  Others should use the Tcl_FS... functions



 * which ensure correct and complete virtual filesystem support.



 */

static Tcl_FSFilesystemSeparatorProc NativeFilesystemSeparator;
static Tcl_FSFreeInternalRepProc NativeFreeInternalRep;
static Tcl_FSFileAttrStringsProc NativeFileAttrStrings;
static Tcl_FSFileAttrsGetProc	NativeFileAttrsGet;
static Tcl_FSFileAttrsSetProc	NativeFileAttrsSet;

/*
 * Functions that support the native filesystem functions listed above.  They
 * are the same for win/unix, and not in tclInt.h because they are and should
 * be used only here.
 */

MODULE_SCOPE const char *const		tclpFileAttrStrings[];
MODULE_SCOPE const TclFileAttrProcs	tclpFileAttrProcs[];


/*
 * These these functions are not static either because routines in the native



 * (win/unix) directories call them or they are actually implemented in those
 * directories. They should be called from outside Tcl's native filesystem
 * routines. If we ever built the native filesystem support into a separate
 * code library, this could actually be enforced.
 */

Tcl_FSFilesystemPathTypeProc	TclpFilesystemPathType;
Tcl_FSInternalToNormalizedProc	TclpNativeToNormalized;
Tcl_FSStatProc			TclpObjStat;
Tcl_FSAccessProc		TclpObjAccess;
Tcl_FSMatchInDirectoryProc	TclpMatchInDirectory;
................................................................................
Tcl_FSCreateDirectoryProc	TclpObjCreateDirectory;
Tcl_FSCopyDirectoryProc		TclpObjCopyDirectory;
Tcl_FSRemoveDirectoryProc	TclpObjRemoveDirectory;
Tcl_FSLinkProc			TclpObjLink;
Tcl_FSListVolumesProc		TclpObjListVolumes;

/*
 * The native filesystem dispatch table.  This could me made public but it
 * should only be accessed by the functions it points to, or perhaps
 * subordinate helper functions.


 */

const Tcl_Filesystem tclNativeFilesystem = {
    "native",
    sizeof(Tcl_Filesystem),
    TCL_FILESYSTEM_VERSION_2,
    TclNativePathInFilesystem,
................................................................................
    /* Needs casts since we're using version_2. */
    (Tcl_FSLoadFileProc *) TclpDlopen,
    (Tcl_FSGetCwdProc *) TclpGetNativeCwd,
    TclpObjChdir
};

/*
 * An initial record in the linked list for the native filesystem.  Remains at
 * the tail of the list and is never freed.  Currently the native filesystem is
 * hard-coded.  It may make sense to modify this to accomodate unconventional
 * uses of Tcl that provide no native filesystem.



 */

static FilesystemRecord nativeFilesystemRecord = {
    NULL,
    &tclNativeFilesystem,
    NULL,
    NULL
};

/*
 * Incremented each time the linked list of filesystems is modified.  For
 * multithreaded builds, invalidates all cached filesystem internal
 * representations.

 */

static size_t theFilesystemEpoch = 1;

/*
 * The linked list of filesystems.  To minimize locking each thread maintains a
 * local copy of this list.
 *
 */

static FilesystemRecord *filesystemList = &nativeFilesystemRecord;
TCL_DECLARE_MUTEX(filesystemMutex)

/*
 * A files-system indepent sense of the current directory.
 */

static Tcl_Obj *cwdPathPtr = NULL;
static size_t cwdPathEpoch = 0;	    /* The pathname of the current directory */
static ClientData cwdClientData = NULL;
TCL_DECLARE_MUTEX(cwdMutex)

static Tcl_ThreadDataKey fsDataKey;

/*
 * When a temporary copy of a file is created on the native filesystem in order
 * to load the file, an FsDivertLoad structure is created to track both the
 * actual unloadProc/clientData combination which was used, and the original and
 * modified filenames.  This makes it possible to correctly undo the entire
 * operation in order to unload the library.

 */

typedef struct {
    Tcl_LoadHandle loadHandle;
    Tcl_FSUnloadFileProc *unloadProcPtr;
    Tcl_Obj *divertedFile;
    const Tcl_Filesystem *divertedFilesystem;
    ClientData divertedFileNativeRep;
} FsDivertLoad;
 
/*
 * Obsolete string-based APIs that should be removed in a future release,
 * perhaps in Tcl 9.
 */

/* Obsolete */
int
Tcl_Stat(
    const char *path,		/* Pathname of file to stat (in current CP). */
    struct stat *oldStyleBuf)	/* Filled with results of stat call. */
{
    int ret;
    Tcl_StatBuf buf;
    Tcl_Obj *pathPtr = Tcl_NewStringObj(path,-1);

    Tcl_IncrRefCount(pathPtr);
................................................................................
    }
    return ret;
}
 
/* Obsolete */
int
Tcl_Access(
    const char *path,		/* Pathname of file to access (in current CP).
				*/
    int mode)			/* Permission setting. */
{
    int ret;
    Tcl_Obj *pathPtr = Tcl_NewStringObj(path,-1);

    Tcl_IncrRefCount(pathPtr);
    ret = Tcl_FSAccess(pathPtr,mode);
................................................................................

    return ret;
}
 
/* Obsolete */
Tcl_Channel
Tcl_OpenFileChannel(
    Tcl_Interp *interp,		/* Interpreter for error reporting. May be
				 * NULL. */
    const char *path,		/* Pathname of file to open. */
    const char *modeString,	/* A list of POSIX open modes or a string such
				 * as "rw". */
    int permissions)		/* The modes to use if creating a new file. */

{
    Tcl_Channel ret;
    Tcl_Obj *pathPtr = Tcl_NewStringObj(path,-1);

    Tcl_IncrRefCount(pathPtr);
    ret = Tcl_FSOpenFileChannel(interp, pathPtr, modeString, permissions);
    Tcl_DecrRefCount(pathPtr);
................................................................................
    TclDStringAppendObj(cwdPtr, cwd);
    Tcl_DecrRefCount(cwd);
    return Tcl_DStringValue(cwdPtr);
}
 
int
Tcl_EvalFile(
    Tcl_Interp *interp,		/* Interpreter in which to evaluate the script. */
    const char *fileName)	/* Pathname of the file containing the script.
				 * Performs Tilde-substitution on this
				 * pathaname. */
{
    int ret;
    Tcl_Obj *pathPtr = Tcl_NewStringObj(fileName,-1);

    Tcl_IncrRefCount(pathPtr);
    ret = Tcl_FSEvalFile(interp, pathPtr);
    Tcl_DecrRefCount(pathPtr);
    return ret;
}
 
/*
 * The basic filesystem implementation.
 */

static void
FsThrExitProc(
    ClientData cd)
{
    ThreadSpecificData *tsdPtr = cd;
    FilesystemRecord *fsRecPtr = NULL, *tmpFsRecPtr = NULL;

    /*
     * Discard the cwd copy.
     */

    if (tsdPtr->cwdPathPtr != NULL) {
	Tcl_DecrRefCount(tsdPtr->cwdPathPtr);
	tsdPtr->cwdPathPtr = NULL;
    }
    if (tsdPtr->cwdClientData != NULL) {
	NativeFreeInternalRep(tsdPtr->cwdClientData);
    }

    /*
     * Discard the filesystems cache.
     */

    fsRecPtr = tsdPtr->filesystemList;
    while (fsRecPtr != NULL) {
	tmpFsRecPtr = fsRecPtr->nextPtr;
	fsRecPtr->fsPtr = NULL;
	ckfree(fsRecPtr);
................................................................................
    }
}
 
/*
 *----------------------------------------------------------------------
 *
 * TclFSCwdPointerEquals --
 *	Determine whether the given pathname is equal to the current working
 *	directory.

 *
 * Results:

 *	1 if equal, 0 otherwise.
 *
 * Side effects:

 *	Updates TSD if needed.
 *
 *	Stores a pointer to the current directory in *pathPtrPtr if it is not
 *	already there and the current directory is not NULL.


 *
 *	If *pathPtrPtr is not null its reference count is decremented
 *	before it is replaced.
 *----------------------------------------------------------------------
 */

int
TclFSCwdPointerEquals(
    Tcl_Obj **pathPtrPtr)
{
................................................................................
	int len1, len2;
	const char *str1, *str2;

	str1 = TclGetStringFromObj(tsdPtr->cwdPathPtr, &len1);
	str2 = TclGetStringFromObj(*pathPtrPtr, &len2);
	if ((len1 == len2) && !memcmp(str1, str2, len1)) {
	    /*
	     * The values are equal but the objects are different.  Cache the
	     * current structure in place of the old one.
	     */

	    Tcl_DecrRefCount(*pathPtrPtr);
	    *pathPtrPtr = tsdPtr->cwdPathPtr;
	    Tcl_IncrRefCount(*pathPtrPtr);
	    return 1;
	} else {
................................................................................
    fsRecPtr = filesystemList;
    while (fsRecPtr != NULL) {
	tmpFsRecPtr = fsRecPtr;
	fsRecPtr = fsRecPtr->nextPtr;
    }

    /*
     * Refill the cache, honouring the order.
     */

    list = NULL;
    fsRecPtr = tmpFsRecPtr;
    while (fsRecPtr != NULL) {
	tmpFsRecPtr = ckalloc(sizeof(FilesystemRecord));
	*tmpFsRecPtr = *fsRecPtr;
................................................................................
	    && (tsdPtr->filesystemEpoch != theFilesystemEpoch))) {
	FsRecacheFilesystemList();
    }
    return tsdPtr->filesystemList;
}
 
/*
 * The epoch can is changed when a filesystems is added or removed, when 
 * "system encoding" changes, and when env(HOME) changes.
 */

int
TclFSEpochOk(
    size_t filesystemEpoch)
{
    return (filesystemEpoch == 0 || filesystemEpoch == theFilesystemEpoch);
................................................................................
{
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&fsDataKey);

    return tsdPtr->filesystemEpoch;
}
 
/*
 * If non-NULL, take posession of clientData and free it later.
 */

static void
FsUpdateCwd(
    Tcl_Obj *cwdObj,
    ClientData clientData)
{
................................................................................
    }

    if (cwdObj == NULL) {
	cwdPathPtr = NULL;
	cwdClientData = NULL;
    } else {
	/*
	 * This must be stored as a string obj!
	 */

	cwdPathPtr = Tcl_NewStringObj(str, len);
	Tcl_IncrRefCount(cwdPathPtr);
	cwdClientData = TclNativeDupInternalRep(clientData);
    }

................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * TclFinalizeFilesystem --
 *
 *	Clean up the filesystem.  After this, any call to a Tcl_FS... function
 *	fails.
 *
 *	If TclResetFilesystem is called later, it restores the filesystem to a
 *	pristine state.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Frees memory allocated for the filesystem.
 *
 *----------------------------------------------------------------------
 */

void
TclFinalizeFilesystem(void)
{
    FilesystemRecord *fsRecPtr;

    /*
     * Assume that only one thread is active. Otherwise mutexes would be needed
     * around this code.
     * TO DO:  This assumption is false, isn't it?
     */

    if (cwdPathPtr != NULL) {
	Tcl_DecrRefCount(cwdPathPtr);
	cwdPathPtr = NULL;
	cwdPathEpoch = 0;
    }
................................................................................
     */

    fsRecPtr = filesystemList;
    while (fsRecPtr != NULL) {
	FilesystemRecord *tmpFsRecPtr = fsRecPtr->nextPtr;

	/*
	 * The native filesystem is static, so don't free it.
	 */

	if (fsRecPtr != &nativeFilesystemRecord) {
	    ckfree(fsRecPtr);
	}
	fsRecPtr = tmpFsRecPtr;
    }
    if (++theFilesystemEpoch == 0) {
	++theFilesystemEpoch;
    }
    filesystemList = NULL;

    /*
     * filesystemList is now NULL. Any attempt to use the filesystem is likely
     * to fail.
     */

#ifdef _WIN32
    TclWinEncodingsCleanup();
#endif
}
 
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSRegister --
 *
 *	Prepends to the list of registered fileystems a new FilesystemRecord

 *	for the given Tcl_Filesystem, which is added even if it is already in
 *	the list.  To determine whether the filesystem is already in the list,
 *	use Tcl_FSData().

 *
 *	Functions that use the list generally process it from head to tail and
 *	use the first filesystem that is suitable.  Therefore, when adding a





 *	diagnostic filsystem (one which simply reports all fs activity), it
 *	must be at the head of the list.  I.e. it must be the last one
 *	registered.
 *
 * Results:
 *	TCL_OK, or TCL_ERROR if memory for a new node in the list could
 *	not be allocated.
 *
 * Side effects:
 *	Allocates memory for a filesystem record and modifies the list of
 *	registered filesystems.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_FSRegister(
    ClientData clientData,	/* Client-specific data for this filesystem. */
    const Tcl_Filesystem *fsPtr)/* The filesystem record for the new fs. */
{
    FilesystemRecord *newFilesystemPtr;

    if (fsPtr == NULL) {
	return TCL_ERROR;
    }

    newFilesystemPtr = ckalloc(sizeof(FilesystemRecord));

    newFilesystemPtr->clientData = clientData;
    newFilesystemPtr->fsPtr = fsPtr;














    Tcl_MutexLock(&filesystemMutex);

    newFilesystemPtr->nextPtr = filesystemList;
    newFilesystemPtr->prevPtr = NULL;
    if (filesystemList) {
	filesystemList->prevPtr = newFilesystemPtr;
    }
    filesystemList = newFilesystemPtr;

    /*
     * Increment the filesystem epoch counter since existing pathnames might
     * conceivably now belong to different filesystems.
     */

    if (++theFilesystemEpoch == 0) {
	++theFilesystemEpoch;
    }
    Tcl_MutexUnlock(&filesystemMutex);
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSUnregister --
 *
 *	Removes the record for given filesystem from the list of registered
 *	filesystems. Refuses to remove the built-in (native) filesystem.  This
 *	might be changed in the future to allow a smaller Tcl core in which the
 *	native filesystem is not used at all, e.g. initializing Tcl over a

 *	network connection.
 *
 * Results:
 *	TCL_OK if the function pointer was successfully removed, or TCL_ERROR
 *	otherwise.
 *
 * Side effects:
 *	The list of registered filesystems is updated.  Memory for the
 *	corresponding FilesystemRecord is eventually freed.

 *
 *----------------------------------------------------------------------
 */

int
Tcl_FSUnregister(
    const Tcl_Filesystem *fsPtr)/* The filesystem record to remove. */
................................................................................
{
    int retVal = TCL_ERROR;
    FilesystemRecord *fsRecPtr;

    Tcl_MutexLock(&filesystemMutex);

    /*
     * Traverse filesystemList in search of the record whose
     * 'fsPtr' member matches 'fsPtr' and remove that record from the list.
     * Do not revmoe the record for the native filesystem.
     */

    fsRecPtr = filesystemList;
    while ((retVal == TCL_ERROR) && (fsRecPtr != &nativeFilesystemRecord)) {
	if (fsRecPtr->fsPtr == fsPtr) {
	    if (fsRecPtr->prevPtr) {
		fsRecPtr->prevPtr->nextPtr = fsRecPtr->nextPtr;
................................................................................
		filesystemList = fsRecPtr->nextPtr;
	    }
	    if (fsRecPtr->nextPtr) {
		fsRecPtr->nextPtr->prevPtr = fsRecPtr->prevPtr;
	    }

	    /*
	     * Each cached pathname could now belong to a different filesystem,
	     * so increment the filesystem epoch counter to ensure that cached

	     * information about the removed filesystem is not used.


	     */

	    if (++theFilesystemEpoch == 0) {
		++theFilesystemEpoch;
	    }

	    ckfree(fsRecPtr);
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSMatchInDirectory --
 *
 *	Search in the given pathname for files matching the given pattern.
 *	Used by [glob].  Processes just one pattern for one directory.  Callers
 *	such as TclGlob and DoGlob implement manage the searching of multiple
 *	directories in cases such as  
 *		glob -dir $dir -join * pkgIndex.tcl







 *




 * Results:
 *



 *	TCL_OK, or TCL_ERROR
 *







 * Side effects:

 *	resultPtr is populated, or in the case of an TCL_ERROR, an error message is
 *	set in the interpreter.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_FSMatchInDirectory(
    Tcl_Interp *interp,		/* Interpreter to receive error messages, or
				 * NULL */
    Tcl_Obj *resultPtr,		/* List that results are added to. */
    Tcl_Obj *pathPtr,		/* Pathname of directory to search. If NULL,
				 * the current working directory is used. */
    const char *pattern,	/* Pattern to match.  If NULL, pathPtr must be
				 * a fully-specified pathname of a single
				 * file/directory which already exists and is
				 * of the correct type. */
    Tcl_GlobTypeData *types)	/* Specifies acceptable types.
				 * May be NULL. The directory flag is

				 * particularly significant. */
{
    const Tcl_Filesystem *fsPtr;
    Tcl_Obj *cwd, *tmpResultPtr, **elemsPtr;
    int resLength, i, ret = -1;

    if (types != NULL && (types->type & TCL_GLOB_TYPE_MOUNT)) {
	/*
	 * Currently external callers may not query mounts, which would be a
	 * valuable future step. This is the only routine that knows about
	 * mounts, so we're being called recursively by ourself. Return no
	 * matches.
	 */

	return TCL_OK;
    }

    if (pathPtr != NULL) {
	fsPtr = Tcl_FSGetFileSystemForPath(pathPtr);
    } else {
	fsPtr = NULL;
    }

    if (fsPtr != NULL) {
	/*

	 * A corresponding filesystem was found. Search within it.
	 */


	if (fsPtr->matchInDirectoryProc == NULL) {
	    Tcl_SetErrno(ENOENT);
	    return -1;
	}
	ret = fsPtr->matchInDirectoryProc(interp, resultPtr, pathPtr, pattern,
		types);
	if (ret == TCL_OK && pattern != NULL) {
	    FsAddMountsToGlobResult(resultPtr, pathPtr, pattern, types);
	}
	return ret;
    }

    if (pathPtr != NULL && TclGetString(pathPtr)[0] != '\0') {
	/*

	 * There is a pathname but it belongs to no known filesystem. Mayday!
	 */


	Tcl_SetErrno(ENOENT);
	return -1;
    }

    /*
     * The pathname is empty or NULL so search in the current working
     * directory.  matchInDirectoryProc prefixes each result with this
     * directory, so trim it from each result.  Deal with this here in the
     * generic code because otherwise every filesystem implementation of

     * Tcl_FSMatchInDirectory has to do it.

     */

    cwd = Tcl_FSGetCwd(NULL);
    if (cwd == NULL) {
	if (interp != NULL) {
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "glob couldn't determine the current working directory",
................................................................................
	Tcl_IncrRefCount(tmpResultPtr);
	ret = fsPtr->matchInDirectoryProc(interp, tmpResultPtr, cwd, pattern,
		types);
	if (ret == TCL_OK) {
	    FsAddMountsToGlobResult(tmpResultPtr, cwd, pattern, types);

	    /*
	     * resultPtr and tmpResultPtr are guaranteed to be distinct.
	     */

	    ret = Tcl_ListObjGetElements(interp, tmpResultPtr,
		    &resLength, &elemsPtr);
	    for (i=0 ; ret==TCL_OK && i<resLength ; i++) {
		ret = Tcl_ListObjAppendElement(interp, resultPtr,
			TclFSMakePathRelative(interp, elemsPtr[i], cwd));
................................................................................
    return ret;
}
 
/*
 *----------------------------------------------------------------------
 *
 * FsAddMountsToGlobResult --
 *	Adds any mounted pathnames to a set of results so that simple things


 *	like 'glob *' merge mounts and listings correctly.  Used by the

 *	Tcl_FSMatchInDirectory.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Stores a result in resultPtr.
 *
 *----------------------------------------------------------------------
 */

static void
FsAddMountsToGlobResult(
    Tcl_Obj *resultPtr,		/* The current list of matching pathnames. Must
				 * not be shared. */
    Tcl_Obj *pathPtr,		/* The directory that was searched. */
    const char *pattern,	/* Pattern to match mounts against. */
    Tcl_GlobTypeData *types)	/* Acceptable types.  May be NULL. The
				 * directory flag is particularly significant.
				 */
{
    int mLength, gLength, i;
    int dir = (types == NULL || (types->type & TCL_GLOB_TYPE_DIR));
    Tcl_Obj *mounts = FsListMounts(pathPtr, pattern);

    if (mounts == NULL) {
	return;
................................................................................
	    }
	}
	if (!found && dir) {
	    Tcl_Obj *norm;
	    int len, mlen;

	    /*
	     * mElt is normalized and lies inside pathPtr so
	     * add to the result the right representation of mElt,
	     * i.e. the representation relative to pathPtr.
	     */

	    norm = Tcl_FSGetNormalizedPath(NULL, pathPtr);
	    if (norm != NULL) {
		const char *path, *mount;

		mount = TclGetStringFromObj(mElt, &mlen);
................................................................................
		    /*
		     * Deal with the root of the volume.
		     */

		    len--;
		}
		len++;		/* account for '/' in the mElt [Bug 1602539] */

		mElt = TclNewFSPathObj(pathPtr, mount + len, mlen - len);

		Tcl_ListObjAppendElement(NULL, resultPtr, mElt);
	    }
	    /*
	     * Not comparing mounts to mounts, so no need to increment gLength

	     */
	}
    }

  endOfMounts:
    Tcl_DecrRefCount(mounts);
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSMountsChanged --
 *
 *	Announecs that mount points have changed or that the system encoding

 *	has changed.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The shared 'theFilesystemEpoch' is incremented, invalidating every
 *	exising cached internal representation of a pathname.  Avoid calling
 *	Tcl_FSMountsChanged whenever possible.  It must be called when:


 *
 *	(1) A filesystem is registered or unregistered. This is only necessary
 *	if the new filesystem accepts file pathnames as-is.  Normally the

 *	filesystem is really a shell which doesn't yet have any mount points
 *	established and so its 'pathInFilesystem' routine always fails.


 *	However, for safety, Tcl calls 'Tcl_FSMountsChanged' each time a
 *	filesystem is registered or unregistered.
 *

 *	(2) An additional mount point is established inside an existing
 *	filesystem (except for the native file system; see note below).
 *


 *	(3) A filesystem changes the list of available volumes (except for the
 *	native file system; see note below).
 *
 *	(4) The mapping from a string representation of a file to a full,
 *	normalized pathname changes. For example, if 'env(HOME)' is modified,
 *	then any pathname containing '~' maps to a different item, possibly in
 *	a different filesystem.


 *
 *	Tcl has no control over (2) and (3), so each registered filesystem must

 *	call Tcl_FSMountsChnaged in each of those circumstances.
 *
 *	The reason for the exception in 2,3 for the native filesystem is that


 *	the native filesystem claims every file without determining whether
 *	whether the file exists, or even whether the pathname makes sense. 
 *
 *----------------------------------------------------------------------
 */

void
Tcl_FSMountsChanged(
    const Tcl_Filesystem *fsPtr)
{
    /*



     * fsPtr is currently unused.  In the future it might invalidate files for
     * a particular filesystem, or take some other more advanced action.
     */

    (void)fsPtr;

    /*
     * Increment the filesystem epoch to invalidate every existing cached
     * internal representation. 
     */

    Tcl_MutexLock(&filesystemMutex);
    if (++theFilesystemEpoch == 0) {
	++theFilesystemEpoch;
    }
    Tcl_MutexUnlock(&filesystemMutex);
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSData --
 *
 *	Retrieves the clientData member of the given filesystem.

 *
 * Results:
 *	A clientData value, or NULL if the given filesystem is not registered.


 *	The clientData value itself may also be NULL.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

ClientData
Tcl_FSData(
    const Tcl_Filesystem *fsPtr) /* The filesystem to find in the list of
				  *  registered filesystems. */
{
    ClientData retVal = NULL;
    FilesystemRecord *fsRecPtr = FsGetFirstFilesystem();

    /*
     * Find the filesystem in and retrieve its clientData.


     */

    while ((retVal == NULL) && (fsRecPtr != NULL)) {
	if (fsRecPtr->fsPtr == fsPtr) {
	    retVal = fsRecPtr->clientData;
	}
	fsRecPtr = fsRecPtr->nextPtr;
................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * TclFSNormalizeToUniquePath --
 *
 *	Converts the given pathname, containing no ../, ./ components, into a
 *	unique pathname for the given platform. On Unix the resulting pathname
 *	is free of symbolic links/aliases, and on Windows it is the long
 *	case-preserving form.

 *
 *
 * Results:
 *	Stores the resulting pathname in pathPtr and returns the offset of the
 *	last byte processed in pathPtr.
 *
 * Side effects:
 *	None (beyond the memory allocation for the result).
 *
 * Special notes:
 *	If the filesystem-specific normalizePathProcs can re-introduce ../, ./
 *	components into the pathname, this function does not return the correct
 *	result. This may be possible with symbolic links on unix.
 *



 *
 *---------------------------------------------------------------------------
 */

int
TclFSNormalizeToUniquePath(
    Tcl_Interp *interp,		/* Used for error messages. */
    Tcl_Obj *pathPtr,		/* An Pathname to normalize in-place.  Must be
				 * unshared. */
    int startAt)		/* Offset the string of pathPtr to start at.
				 * Must either be 0 or offset of a directory
				 * separator at the end of a pathname part that
				 * is already normalized, I.e. not the index of
				 * the byte just after the separator.  */
{
    FilesystemRecord *fsRecPtr, *firstFsRecPtr;

    int i;
    int isVfsPath = 0;
    const char *path;

    /*
     * Pathnames starting with a UNC prefix and ending with a colon character
     * are reserved for VFS use.  These names can not conflict with real UNC
     * pathnames per https://msdn.microsoft.com/en-us/library/gg465305.aspx and
     * rfc3986's definition of reg-name.
     *
     * We check these first to avoid useless calls to the native filesystem's
     * normalizePathProc.
     */
    path = Tcl_GetStringFromObj(pathPtr, &i);

    if ( (i >= 3) && ( (path[0] == '/' && path[1] == '/')
................................................................................
	    if (path[i] == path[0]) break;
	}
	--i;
	if (path[i] == ':') isVfsPath = 1;
    }

    /*
     * Call the the normalizePathProc routine of each registered filesystem.
     */
    firstFsRecPtr = FsGetFirstFilesystem();

    Claim();

    if (!isVfsPath) {

	/*
	 * Find and call the native filesystem handler first if there is one
	 * because the root of Tcl's filesystem is always a native filesystem
	 * (i.e., '/' on unix is native).
	 */

	for (fsRecPtr=firstFsRecPtr; fsRecPtr!=NULL; fsRecPtr=fsRecPtr->nextPtr) {
	    if (fsRecPtr->fsPtr != &tclNativeFilesystem) {
		continue;
	    }

	    /*
	     * TODO: Always call the normalizePathProc here because it should
	     * always exist.
	     */

	    if (fsRecPtr->fsPtr->normalizePathProc != NULL) {
		startAt = fsRecPtr->fsPtr->normalizePathProc(interp, pathPtr,
			startAt);
	    }
	    break;
	}
    }

    for (fsRecPtr=firstFsRecPtr; fsRecPtr!=NULL; fsRecPtr=fsRecPtr->nextPtr) {
	if (fsRecPtr->fsPtr == &tclNativeFilesystem) {
	    /*
	     * Skip the native system this time through.
	     */


	    continue;
	}

	if (fsRecPtr->fsPtr->normalizePathProc != NULL) {
	    startAt = fsRecPtr->fsPtr->normalizePathProc(interp, pathPtr,
		    startAt);
	}

	/*
	 * This efficiency check could be added:
	 *		if (retVal == length-of(pathPtr)) {break;}
	 * but there's not much benefit.
	 */
    }
    Disclaim();

    return startAt;
................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * TclGetOpenMode --
 *
 *	Obsolete.  A limited version of TclGetOpenModeEx() which exists only to
 *	satisfy any extensions imprudently using it via Tcl's internal stubs
 *	table.
 *
 * Results:
 *	See TclGetOpenModeEx().
 *
 * Side effects:
 *	See TclGetOpenModeEx().
 *
 *---------------------------------------------------------------------------
 */

int
TclGetOpenMode(
    Tcl_Interp *interp,		/* Interpreter to use for error reporting.  May
				 *  be NULL. */
    const char *modeString,	/* e.g. "r+" or "RDONLY CREAT". */
    int *seekFlagPtr)		/* Sets this to 1 to tell the caller to seek to
				   EOF after opening the file, and
				 * 0 otherwise. */
{
    int binary = 0;
    return TclGetOpenModeEx(interp, modeString, seekFlagPtr, &binary);
}
 
/*
 *---------------------------------------------------------------------------
 *
 * TclGetOpenModeEx --
 *
 *	Computes a POSIX mode mask for opening a file.



 *
 * Results:
 *	The mode to pass to "open", or -1 if an error occurs.


 *
 * Side effects:
 *	Sets *seekFlagPtr to 1 to tell the caller to
 *	seek to EOF after opening the file, or to 0 otherwise.
 *
 *	Sets *binaryPtr to 1 to tell the caller to configure the channel as a
 *	binary channel, or to 0 otherwise.
 *
 *	If there is an error and interp is not NULL, sets interpreter result to
 *	an error message.
 *
 * Special note:
 *	Based on a prototype implementation contributed by Mark Diekhans.

 *
 *---------------------------------------------------------------------------
 */

int
TclGetOpenModeEx(
    Tcl_Interp *interp,		/* Interpreter, possibly NULL, to use for
				 * error reporting. */
    const char *modeString,	/* Mode string, e.g. "r+" or "RDONLY CREAT" */
    int *seekFlagPtr,		/* Sets this to 1 to tell the the caller to seek to
				 * EOF after opening the file, and 0 otherwise. */
    int *binaryPtr)		/* Sets this to 1 to tell the caller to 
				 * configure the channel for binary
				 * operations after opening the file. */
{
    int mode, modeArgc, c, i, gotRW;
    const char **modeArgv, *flag;
#define RW_MODES (O_RDONLY|O_WRONLY|O_RDWR)

    /*
     * Check for the simpler fopen-like access modes like "r" which are
     * distinguished from the POSIX access modes by the presence of a
     * lower-case first letter.
     */

    *seekFlagPtr = 0;
    *binaryPtr = 0;
    mode = 0;

    /*
     * Guard against wide characters before using byte-oriented routines.

     */

    if (!(modeString[0] & 0x80)
	    && islower(UCHAR(modeString[0]))) { /* INTL: ISO only. */
	switch (modeString[0]) {
	case 'r':
	    mode = O_RDONLY;
	    break;
	case 'w':
	    mode = O_WRONLY|O_CREAT|O_TRUNC;
	    break;
	case 'a':
	    /*
	     * Add O_APPEND for proper automatic seek-to-end-on-write by the
	     * OS. [Bug 680143]
	     */

	    mode = O_WRONLY|O_CREAT|O_APPEND;
	    *seekFlagPtr = 1;
	    break;
	default:
................................................................................
	while (i<3 && modeString[i]) {
	    if (modeString[i] == modeString[i-1]) {
		goto error;
	    }
	    switch (modeString[i++]) {
	    case '+':
		/*
		 * Remove O_APPEND so that the seek command works. [Bug
		 * 1773127]
		 */

		mode &= ~(O_RDONLY|O_WRONLY|O_APPEND);
		mode |= O_RDWR;
		break;
	    case 'b':
		*binaryPtr = 1;
................................................................................
	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		    "illegal access mode \"%s\"", modeString));
	}
	return -1;
    }

    /*
     * The access modes are specified as a list of POSIX modes like O_CREAT.

     *


     * Tcl_SplitList must work correctly when interp is NULL.
     */

    if (Tcl_SplitList(interp, modeString, &modeArgc, &modeArgv) != TCL_OK) {
	if (interp != NULL) {
	    Tcl_AddErrorInfo(interp,
		    "\n    while processing open access modes \"");
	    Tcl_AddErrorInfo(interp, modeString);
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSEvalFile, Tcl_FSEvalFileEx, TclNREvalFile --
 *
 *	Reads a file and evaluates it as a script.
 *
 *	Tcl_FSEvalFile is Tcl_FSEvalFileEx without the encoding argument.
 *
 *	TclNREvalFile is an NRE-enabled version of Tcl_FSEvalFileEx.
 *
 * Results:
 *	A standard Tcl result, which is either the result of executing the
 *	file or an error indicating why the file couldn't be read.
 *
 * Side effects:
 *	Arbitrary, depending on the contents of the script.  While the script
 *	is evaluated iPtr->scriptFile is a reference to pathPtr, and after the
 *	evaluation completes, has its original value restored again.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_FSEvalFile(
    Tcl_Interp *interp,		/* Interpreter that evaluates the script. */
    Tcl_Obj *pathPtr)		/* Pathname of file containing the script.
				 * Tilde-substitution is performed on this
				 * pathname. */
{
    return Tcl_FSEvalFileEx(interp, pathPtr, NULL);
}

int
Tcl_FSEvalFileEx(
    Tcl_Interp *interp,		/* Interpreter that evaluates the script. */
    Tcl_Obj *pathPtr,		/* Pathname of the file to process.
				 * Tilde-substitution is performed on this
				 * pathname. */
    const char *encodingName)	/* Either the name of an encoding or NULL to
				   use the system encoding. */
{
    int length, result = TCL_ERROR;
    Tcl_StatBuf statBuf;
    Tcl_Obj *oldScriptFile;
    Interp *iPtr;
    const char *string;
    Tcl_Channel chan;
................................................................................
	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		"couldn't read file \"%s\": %s",
		Tcl_GetString(pathPtr), Tcl_PosixError(interp)));
	return result;
    }

    /*
     * The eof character is \32 (^Z). This is standard on Windows, and Tcl 
     * uses it on every platform to allow for scripted documents. [Bug: 2040]
     */

    Tcl_SetChannelOption(interp, chan, "-eofchar", "\32 {}");

    /*
     * If the encoding is specified, set the channel to that encoding.
     * Otherwise don't touch it, leaving things up to the system encoding.  If
     * the encoding is unknown report an error.
     */

    if (encodingName != NULL) {
	if (Tcl_SetChannelOption(interp, chan, "-encoding", encodingName)
		!= TCL_OK) {
	    Tcl_Close(interp,chan);
	    return result;
................................................................................
	}
    }

    objPtr = Tcl_NewObj();
    Tcl_IncrRefCount(objPtr);

    /*
     * Read first character of stream to check for utf-8 BOM

     */

    if (Tcl_ReadChars(chan, objPtr, 1, 0) == TCL_IO_FAILURE) {
	Tcl_Close(interp, chan);
	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		"couldn't read file \"%s\": %s",
		Tcl_GetString(pathPtr), Tcl_PosixError(interp)));
	goto end;
    }
    string = Tcl_GetString(objPtr);

    /*
     * If first character is not a BOM, append the remaining characters.
     * Otherwise, replace them. [Bug 3466099]
     */

    if (Tcl_ReadChars(chan, objPtr, -1,
	    memcmp(string, "\xef\xbb\xbf", 3)) == TCL_IO_FAILURE) {
	Tcl_Close(interp, chan);
	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		"couldn't read file \"%s\": %s",
................................................................................
    iPtr = (Interp *) interp;
    oldScriptFile = iPtr->scriptFile;
    iPtr->scriptFile = pathPtr;
    Tcl_IncrRefCount(iPtr->scriptFile);
    string = TclGetStringFromObj(objPtr, &length);

    /*
     * TIP #280:  Open a frame for the evaluated script.
     */

    iPtr->evalFlags |= TCL_EVAL_FILE;
    result = TclEvalEx(interp, string, length, 0, 1, NULL, string);

    /*
     * Restore the original iPtr->scriptFile value, but because the value may
     * have hanged during evaluation, don't assume it currently points to
     * pathPtr.
     */

    if (iPtr->scriptFile != NULL) {
	Tcl_DecrRefCount(iPtr->scriptFile);
    }
    iPtr->scriptFile = oldScriptFile;

    if (result == TCL_RETURN) {
	result = TclUpdateReturnInfo(iPtr);
    } else if (result == TCL_ERROR) {
	/*
	 * Record information about where the error occurred.
	 */

	const char *pathString = TclGetStringFromObj(pathPtr, &length);
	int limit = 150;
	int overflow = (length > limit);

	Tcl_AppendObjToErrorInfo(interp, Tcl_ObjPrintf(
................................................................................
  end:
    Tcl_DecrRefCount(objPtr);
    return result;
}

int
TclNREvalFile(
    Tcl_Interp *interp,		/* Interpreter in which to evaluate the script. */
    Tcl_Obj *pathPtr,		/* Pathname of a file containing the script to
				 * evaluate. Tilde-substitution is performed on
				 * this pathname. */
    const char *encodingName)	/* The name of an encoding to use, or NULL to
				 *  use the system encoding. */
{
    Tcl_StatBuf statBuf;
    Tcl_Obj *oldScriptFile, *objPtr;
    Interp *iPtr;
    Tcl_Channel chan;
    const char *string;

................................................................................
		"couldn't read file \"%s\": %s",
		Tcl_GetString(pathPtr), Tcl_PosixError(interp)));
	return TCL_ERROR;
    }
    TclPkgFileSeen(interp, Tcl_GetString(pathPtr));

    /*
     * The eof character is \32 (^Z). This is standard on Windows, and Tcl 
     * uses it on every platform to allow for scripted documents. [Bug: 2040]
     */

    Tcl_SetChannelOption(interp, chan, "-eofchar", "\32 {}");

    /*
     * If the encoding is specified, set the channel to that encoding.
     * Otherwise don't touch it, leaving things up to the system encoding.  If
     * the encoding is unknown report an error.
     */

    if (encodingName != NULL) {
	if (Tcl_SetChannelOption(interp, chan, "-encoding", encodingName)
		!= TCL_OK) {
	    Tcl_Close(interp,chan);
	    return TCL_ERROR;
................................................................................
	}
    }

    objPtr = Tcl_NewObj();
    Tcl_IncrRefCount(objPtr);

    /*
     * Read first character of stream to check for utf-8 BOM

     */

    if (Tcl_ReadChars(chan, objPtr, 1, 0) == TCL_IO_FAILURE) {
	Tcl_Close(interp, chan);
	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		"couldn't read file \"%s\": %s",
		Tcl_GetString(pathPtr), Tcl_PosixError(interp)));
	Tcl_DecrRefCount(objPtr);
	return TCL_ERROR;
    }
    string = Tcl_GetString(objPtr);

    /*
     * If first character is not a BOM, append the remaining characters.
     * Otherwise, replace them. [Bug 3466099]
     */

    if (Tcl_ReadChars(chan, objPtr, -1,
	    memcmp(string, "\xef\xbb\xbf", 3)) == TCL_IO_FAILURE) {
	Tcl_Close(interp, chan);
	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		"couldn't read file \"%s\": %s",
................................................................................

    iPtr = (Interp *) interp;
    oldScriptFile = iPtr->scriptFile;
    iPtr->scriptFile = pathPtr;
    Tcl_IncrRefCount(iPtr->scriptFile);

    /*
     * TIP #280:  Open a frame for the evaluated script.
     */

    iPtr->evalFlags |= TCL_EVAL_FILE;
    TclNRAddCallback(interp, EvalFileCallback, oldScriptFile, pathPtr, objPtr,
	    NULL);
    return TclNREvalObjEx(interp, objPtr, 0, NULL, INT_MIN);
}
................................................................................
{
    Interp *iPtr = (Interp *) interp;
    Tcl_Obj *oldScriptFile = data[0];
    Tcl_Obj *pathPtr = data[1];
    Tcl_Obj *objPtr = data[2];

    /*
     * Restore the original iPtr->scriptFile value, but because the value may
     * have hanged during evaluation, don't assume it currently points to
     * pathPtr.
     */

    if (iPtr->scriptFile != NULL) {
	Tcl_DecrRefCount(iPtr->scriptFile);
    }
    iPtr->scriptFile = oldScriptFile;

    if (result == TCL_RETURN) {
	result = TclUpdateReturnInfo(iPtr);
    } else if (result == TCL_ERROR) {
	/*
	 * Record information about where the error occurred.
	 */

	int length;
	const char *pathString = TclGetStringFromObj(pathPtr, &length);
	const int limit = 150;
	int overflow = (length > limit);

................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_GetErrno --
 *

 *	Currently the global variable "errno", but could in the future change
 *	to something else.
 *
 * Results:
 *	The current Tcl error number.
 *
 * Side effects:
 *	None. The value of the Tcl error code variable is only defined if it
 *	was set by a previous call to Tcl_SetErrno.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_GetErrno(void)
{
    /*
     * On some platforms errno is thread-local, as implemented by the C
     * library.
     */

    return errno;
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_SetErrno --
 *
 *	Sets the Tcl error code to the given value. On some saner platforms
 *	this is implemented in the C library as a thread-local value , but this
 *	is *really* unsafe to assume!
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Modifies the the Tcl error code value.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_SetErrno(
    int err)			/* The new value. */
{
    /*
     * On some platforms, errno is implemented by the C library as a thread
     * local value
     */

    errno = err;
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_PosixError --
 *
 *	Typically called after a UNIX kernel call returns an error.  Sets the
 *	interpreter errorCode to machine-parsable information about the error.


 *
 * Results:
 *	A human-readable sring describing the error.
 *
 * Side effects:

 *	Sets the errorCode value of the interpreter.
 *
 *----------------------------------------------------------------------
 */

const char *
Tcl_PosixError(
    Tcl_Interp *interp)		/* Interpreter to set the errorCode of */

{
    const char *id, *msg;

    msg = Tcl_ErrnoMsg(errno);
    id = Tcl_ErrnoId();
    if (interp) {
	Tcl_SetErrorCode(interp, "POSIX", id, msg, NULL);
................................................................................
    return msg;
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSStat --
 *	Calls 'statProc' of the filesystem corresponding to pathPtr. 
 *

 *	Replaces the standard library routines stat.
 *


 *
 * Results:
 *	See stat documentation.
 *
 * Side effects:
 *	See stat documentation.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_FSStat(
    Tcl_Obj *pathPtr,		/* Pathname of the file to call stat on (in
				 *  current CP). */
    Tcl_StatBuf *buf)		/* A buffer to hold the results of the call to
				 *  stat. */
{
    const Tcl_Filesystem *fsPtr = Tcl_FSGetFileSystemForPath(pathPtr);

    if (fsPtr != NULL && fsPtr->statProc != NULL) {
	return fsPtr->statProc(pathPtr, buf);
    }
    Tcl_SetErrno(ENOENT);
................................................................................
    return -1;
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSLstat --
 *	Calls the 'lstatProc' of the filesystem corresponding to pathPtr. 
 *
 *	Replaces the library version of lstat.  If the filesystem doesn't

 *	provide lstatProc but does provide statProc, Tcl falls back to
 *	statProc.
 *
 * Results:
 *	See lstat documentation.
 *
 * Side effects:
 *	See lstat documentation.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_FSLstat(
    Tcl_Obj *pathPtr,		/* Pathname of the file to call stat on (in
				   current CP). */
    Tcl_StatBuf *buf)		/* Filled with results of that call to stat. */
{
    const Tcl_Filesystem *fsPtr = Tcl_FSGetFileSystemForPath(pathPtr);

    if (fsPtr != NULL) {
	if (fsPtr->lstatProc != NULL) {
	    return fsPtr->lstatProc(pathPtr, buf);
	}
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSAccess --
 *
 *	Calls 'accessProc' of the filesystem corresponding to pathPtr.
 *
 *	Replaces the library version of access.
 *
 * Results:
 *	See access documentation.
 *
 * Side effects:
 *	See access documentation.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_FSAccess(
    Tcl_Obj *pathPtr,		/* Pathname of file to access (in current CP). */
    int mode)			/* Permission setting. */
{
    const Tcl_Filesystem *fsPtr = Tcl_FSGetFileSystemForPath(pathPtr);

    if (fsPtr != NULL && fsPtr->accessProc != NULL) {
	return fsPtr->accessProc(pathPtr, mode);
    }
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSOpenFileChannel --
 *
 *	Calls 'openfileChannelProc' of the filesystem corresponding to
 *	pathPtr.
 *
 * Results:
 *	The new channel, or NULL if the named file could not be opened.
 *
 * Side effects:
 *	Opens a channel, possibly creating the corresponding the file on the
 *	filesystem.
 *
 *----------------------------------------------------------------------
 */

Tcl_Channel
Tcl_FSOpenFileChannel(
    Tcl_Interp *interp,		/* Interpreter for error reporting, or NULL */

    Tcl_Obj *pathPtr,		/* Pathname of file to open. */
    const char *modeString,	/* A list of POSIX open modes or a string such
				 * as "rw". */
    int permissions)		/* What modes to use if opening the file
				   involves creating it. */

{
    const Tcl_Filesystem *fsPtr;
    Tcl_Channel retVal = NULL;


    if (Tcl_FSGetNormalizedPath(interp, pathPtr) == NULL) {
	/*
	 * Return the correct error message. 

	 */


	return NULL;
    }

    fsPtr = Tcl_FSGetFileSystemForPath(pathPtr);
    if (fsPtr != NULL && fsPtr->openFileChannelProc != NULL) {
	int mode, seekFlag, binary;

	/*
	 * Parse the mode to determine whether to seek at the outset
	 * and/or set the channel into binary mode.
	 */

	mode = TclGetOpenModeEx(interp, modeString, &seekFlag, &binary);
	if (mode == -1) {
	    return NULL;
	}

	/*
	 * Open the file.
	 */

	retVal = fsPtr->openFileChannelProc(interp, pathPtr, mode,
		permissions);
	if (retVal == NULL) {
	    return NULL;
	}

	/*
	 * Seek and/or set binary mode as determined above.
	 */

	if (seekFlag && Tcl_Seek(retVal, (Tcl_WideInt) 0, SEEK_END)
		< (Tcl_WideInt) 0) {
	    if (interp != NULL) {
		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
			"could not seek to end of file while opening \"%s\": %s",
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSUtime --
 *
 *	Calls 'uTimeProc' of the filesystem corresponding to the given
 *	pathname.
 *
 *	Replaces the library version of utime.

 *
 * Results:
 *	See utime documentation.
 *
 * Side effects:
 *	See utime documentation.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_FSUtime(
    Tcl_Obj *pathPtr,		/* Pathaname of file to call uTimeProc on */

    struct utimbuf *tval)	/* Specifies the access/modification
				 * times to use. Should not be modified. */
{
    const Tcl_Filesystem *fsPtr = Tcl_FSGetFileSystemForPath(pathPtr);

    if (fsPtr != NULL && fsPtr->utimeProc != NULL) {
	return fsPtr->utimeProc(pathPtr, tval);
    }
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * NativeFileAttrStrings --
 *
 *	Implements the platform-dependent 'file attributes' subcommand for the
 *	native filesystem, for listing the set of possible attribute strings.
 *	Part of Tcl's native filesystem support. Placed here because it is used
 *	under both Unix and Windows.

 *
 * Results:
 *	An array of strings
 *
 * Side effects:
 *	None.
 *
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * NativeFileAttrsGet --
 *
 *	Implements the platform-dependent 'file attributes' subcommand for the
 *	native filesystem for 'get' operations.  Part of Tcl's native
 *	filesystem support.  Defined here because it is used under both Unix
 *	and Windows.
 *
 * Results:
 *	Standard Tcl return code.

 *
 *	If there was no error, stores in objPtrRef a pointer to a new object
 *	having a refCount of zero and  holding the result.  The caller should
 *	store it somewhere, e.g. as the Tcl result, or decrement its refCount
 *	to free it.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
NativeFileAttrsGet(
    Tcl_Interp *interp,		/* The interpreter for error reporting. */
    int index,			/* index of the attribute command. */
    Tcl_Obj *pathPtr,		/* Pathname of the file */
    Tcl_Obj **objPtrRef)	/* Where to store the a pointer to the result. */
{
    return tclpFileAttrProcs[index].getProc(interp, index, pathPtr,objPtrRef);
}
 
/*
 *----------------------------------------------------------------------
 *
 * NativeFileAttrsSet --
 *
 *	Implements the platform-dependent 'file attributes' subcommand for the
 *	native filesystem for 'set' operations.  A part of Tcl's native
 *	filesystem support, it is defined here because it is used under both
 *	Unix and Windows.
 *
 * Results:
 *	A standard Tcl return code.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
NativeFileAttrsSet(
    Tcl_Interp *interp,		/* The interpreter for error reporting. */
    int index,			/* index of the attribute command. */
    Tcl_Obj *pathPtr,		/* Pathname of the file */
    Tcl_Obj *objPtr)		/* The value to set. */
{
    return tclpFileAttrProcs[index].setProc(interp, index, pathPtr, objPtr);
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSFileAttrStrings --
 *
 *	Implements part of the hookable 'file attributes'
 *	subcommand.

 *
 *	Calls 'fileAttrStringsProc' of the filesystem corresponding to the
 *	given pathname.
 *
 * Results:
 *	Returns an array of strings, or returns NULL and stores in objPtrRef


 *	a pointer to a new Tcl list having a refCount of zero, and containing
 *	the file attribute strings.


 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * TclFSFileAttrIndex --
 *
 *	Given an attribute name, determines the index of the attribute in the
 *	attribute table.
 *
 * Results:
 *	A standard Tcl result code.
 *
 *	If there is no error, stores the index in *indexPtr.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

int
TclFSFileAttrIndex(
    Tcl_Obj *pathPtr,		/* Pathname of the file. */

    const char *attributeName,	/* The name of the attribute. */
    int *indexPtr)		/* A place to store the result. */
{
    Tcl_Obj *listObj = NULL;
    const char *const *attrTable;

    /*
     * Get the attribute table for the file.
     */
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSFileAttrsGet --
 *
 *	Implements read access for the hookable 'file attributes' subcommand.
 *
 *	Calls 'fileAttrsGetProc' of the filesystem corresponding to the given
 *	pathname.
 *
 * Results:
 *	A standard Tcl return code.
 *
 *	On success, stores in objPtrRef a pointer to a new Tcl_Obj having a
 *	refCount of zero, and containing the result.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_FSFileAttrsGet(
    Tcl_Interp *interp,		/* The interpreter for error reporting. */
    int index,			/* The index of the attribute command. */
    Tcl_Obj *pathPtr,		/* The pathname of the file. */
    Tcl_Obj **objPtrRef)	/* A place to store the result. */
{
    const Tcl_Filesystem *fsPtr = Tcl_FSGetFileSystemForPath(pathPtr);

    if (fsPtr != NULL && fsPtr->fileAttrsGetProc != NULL) {
	return fsPtr->fileAttrsGetProc(interp, index, pathPtr, objPtrRef);
    }
    Tcl_SetErrno(ENOENT);
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSFileAttrsSet --
 *
 *	Implements write access for the hookable 'file
 *	attributes' subcommand.

 *
 *	Calls 'fileAttrsSetProc' for the filesystem corresponding to the given
 *	pathname.
 *
 * Results:
 *	A standard Tcl return code.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_FSFileAttrsSet(
    Tcl_Interp *interp,		/* The interpreter for error reporting. */
    int index,			/* The index of the attribute command. */
    Tcl_Obj *pathPtr,		/* The pathname of the file. */
    Tcl_Obj *objPtr)		/* A place to store the result. */
{
    const Tcl_Filesystem *fsPtr = Tcl_FSGetFileSystemForPath(pathPtr);

    if (fsPtr != NULL && fsPtr->fileAttrsSetProc != NULL) {
	return fsPtr->fileAttrsSetProc(interp, index, pathPtr, objPtr);
    }
    Tcl_SetErrno(ENOENT);
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSGetCwd --
 *
 *	Replaces the library version of getcwd().
 *
 *	Most virtual filesystems do not implement cwdProc. Tcl maintains its
 *	own record of the current directory which it keeps synchronized with
 *	the filesystem corresponding to the pathname of the current directory
 *	if the filesystem provides a cwdProc (the native filesystem does).
 *
 *	If Tcl's current directory is not in the native filesystem, Tcl's
 *	current directory and the current directory of the process are
 *	different.  To avoid confusion, extensions should call Tcl_FSGetCwd to
 *	obtain the current directory from Tcl rather than from the operating
 *	system.



 *




 * Results:



 *	Returns a pointer to a Tcl_Obj having a refCount of 1 and containing
 *	the current thread's local copy of the global cwdPathPtr value.
 *


 *	Returns NULL if the current directory could not be determined, and
 *	leaves an error message in the interpreter's result.
 *
 * Side effects:
 *	Various objects may be freed and allocated.
 *
 *----------------------------------------------------------------------
 */

................................................................................
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&fsDataKey);

    if (TclFSCwdPointerEquals(NULL)) {
	FilesystemRecord *fsRecPtr;
	Tcl_Obj *retVal = NULL;

	/*
	 * This is the first time this routine has been called. Call
	 * 'getCwdProc' for each registered filsystems until one returns
	 * something other than NULL, which is a pointer to the pathname of the
	 * current directory.
	 */

	fsRecPtr = FsGetFirstFilesystem();
	Claim();
	for (; (retVal == NULL) && (fsRecPtr != NULL);
		fsRecPtr = fsRecPtr->nextPtr) {
	    ClientData retCd;
................................................................................

	    proc2 = (TclFSGetCwdProc2 *) fsRecPtr->fsPtr->getCwdProc;
	    retCd = proc2(NULL);
	    if (retCd != NULL) {
		Tcl_Obj *norm;

		/*
		 * Found the pathname of the current directory.
		 */

		retVal = fsRecPtr->fsPtr->internalToNormalizedProc(retCd);
		Tcl_IncrRefCount(retVal);
		norm = TclFSNormalizeAbsolutePath(interp,retVal);
		if (norm != NULL) {
		    /*
		     * Assign to global storage the pathname of the current directory 
		     * and copy it into thread-local storage as well.
		     *
		     * At system startup multiple threads could in principle
		     * call this function simultaneously, which is a little


		     * peculiar, but should be fine given the mutex locks in
		     * FSUPdateCWD.  Once some value is assigned to the global
		     * variable the 'else' branch below is always taken, which
		     * is simpler.
		     */

		    FsUpdateCwd(norm, retCd);
		    Tcl_DecrRefCount(norm);
		} else {
		    fsRecPtr->fsPtr->freeInternalRepProc(retCd);
		}
................................................................................
		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
			"error getting working directory name: %s",
			Tcl_PosixError(interp)));
	    }
	}
	Disclaim();

	if (retVal != NULL) {
	    /*

	     * On some platforms the pathname of the current directory might
	     * not be normalized.  For efficiency, ensure that it is
	     * normalized.  For the sake of efficiency, we want a completely


	     * normalized current working directory at all times.

	     */


	    Tcl_Obj *norm = TclFSNormalizeAbsolutePath(interp, retVal);

	    if (norm != NULL) {
		/*
		 * We found a current working directory, which is now in our
		 * global storage. We must make a copy. Norm already has a
		 * refCount of 1.
		 *
		 * Threading issue: Multiple threads at system startup could in
		 * principle call this function simultaneously. They will
		 * therefore each set the cwdPathPtr independently, which is a

		 * bit peculiar, but should be fine. Once we have a cwd, we'll
		 * always be in the 'else' branch below which is simpler.
		 */

		ClientData cd = (ClientData) Tcl_FSGetNativePath(norm);

		FsUpdateCwd(norm, TclNativeDupInternalRep(cd));
		Tcl_DecrRefCount(norm);
	    }
	    Tcl_DecrRefCount(retVal);
	} else {
	    /*
	     * retVal is NULL.  There is no current directory, which could be
	     * problematic.
	    */
	}
    } else {
	/*
	 * There is a thread-local value for the pathname of the current
	 * directory.  Give corresponding filesystem a chance update the value
	 * if it is out-of-date. This allows an error to be thrown if, for
	 * example, the permissions on the current working directory have
	 * changed.
	 */

	const Tcl_Filesystem *fsPtr =
		Tcl_FSGetFileSystemForPath(tsdPtr->cwdPathPtr);
	ClientData retCd = NULL;
	Tcl_Obj *retVal, *norm;

	if (fsPtr == NULL || fsPtr->getCwdProc == NULL) {
	    /*

	     * There is no corresponding filesystem or the filesystem does not
	     * have a getCwd routine. Just assume current local value is ok.



	     */


	    goto cdDidNotChange;
	}

	if (fsPtr->version == TCL_FILESYSTEM_VERSION_1) {
	    retVal = fsPtr->getCwdProc(interp);
	} else {
	    /*
................................................................................
	     * Looks like a new current directory.
	     */

	    retVal = fsPtr->internalToNormalizedProc(retCd);
	    Tcl_IncrRefCount(retVal);
	}

	if (retVal == NULL) {
	    /*

	     * The current directory could not not determined.  Reset the
	     * current direcory to ensure, for example, that 'pwd' does actually
	     * throw the correct error in Tcl.  This is tested for in the test
	     * suite on unix.
	     */


	    FsUpdateCwd(NULL, NULL);
	    goto cdDidNotChange;
	}





	norm = TclFSNormalizeAbsolutePath(interp, retVal);

	if (norm == NULL) {
	     /*

	     * 'norm' shouldn't ever be NULL, but we are careful.
	     */


	    /* Do nothing */
	    if (retCd != NULL) {
		fsPtr->freeInternalRepProc(retCd);
	    }
	} else if (norm == tsdPtr->cwdPathPtr) {
	    goto cdEqual;
	} else {
	     /*
	     * Determine whether the filesystem's answer is the same as the
	     * cached local value.  Since both 'norm' and 'tsdPtr->cwdPathPtr'

	     * are normalized pathnames, do something more efficient than
	     * calling 'Tcl_FSEqualPaths', and in addition avoid a nasty
	     * infinite loop bug when trying to normalize tsdPtr->cwdPathPtr.
	     */

	    int len1, len2;
	    const char *str1, *str2;

	    str1 = TclGetStringFromObj(tsdPtr->cwdPathPtr, &len1);
	    str2 = TclGetStringFromObj(norm, &len2);
	    if ((len1 == len2) && (strcmp(str1, str2) == 0)) {
		/*
		 * The pathname values are equal so retain the old pathname
		 * object which is probably already shared and free the
		 * normalized pathname that was just produced.

		 */

	    cdEqual:
		Tcl_DecrRefCount(norm);
		if (retCd != NULL) {
		    fsPtr->freeInternalRepProc(retCd);
		}
	    } else {
		/*
		 * The pathname of the current directory is not the same as
		 * this thread's local cached value.  Replace the local value.
		 */
		FsUpdateCwd(norm, retCd);
		Tcl_DecrRefCount(norm);
	    }
	}
	Tcl_DecrRefCount(retVal);
    }

................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSChdir --
 *
 *	Replaces the library version of chdir().
 *
 *	Calls 'chdirProc' of the filesystem that corresponds to the given
 *	pathname.
 *
 * Results:
 *	See chdir() documentation.

 *
 * Side effects:
 *	See chdir() documentation.
 *
 *	On success stores in cwdPathPtr the pathname of the new current
 *	directory.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_FSChdir(
    Tcl_Obj *pathPtr)
................................................................................
	return retVal;
    }

    fsPtr = Tcl_FSGetFileSystemForPath(pathPtr);
    if (fsPtr != NULL) {
	if (fsPtr->chdirProc != NULL) {
	    /*

	     * If this fails Tcl_SetErrno() has already been called.
	     */

	    retVal = fsPtr->chdirProc(pathPtr);
	} else {
	    /*
	     * Fallback to stat-based implementation.
	     */

	    Tcl_StatBuf buf;








	    if ((Tcl_FSStat(pathPtr, &buf) == 0) && (S_ISDIR(buf.st_mode))
		    && (Tcl_FSAccess(pathPtr, R_OK) == 0)) {
		/*
		 * stat was successful, and the file is a directory and is
		 * readable.  Can proceed to change the current directory.
		 */

		retVal = 0;
	    } else {
		 /*
		 * 'Tcl_SetErrno()' has already been called.
		 */
	    }
	}
    } else {
	Tcl_SetErrno(ENOENT);
    }




    if (retVal == 0) {

	 /* Assume that the cwd was actually changed to the normalized value

	  * just calculated, and cache that information.  */



















	/*




	 * If the filesystem epoch changed recently, the normalized pathname or
	 * its internal handle may be different from what was found above.
	 * This can easily be the case with scripted documents . Therefore get
	 * the normalized pathname again. The correct value will have been
	 * cached as a result of the Tcl_FSGetFileSystemForPath call, above.
	 */

	Tcl_Obj *normDirName = Tcl_FSGetNormalizedPath(NULL, pathPtr);

	if (normDirName == NULL) {
	    /* Not really true, but what else to do? */
	    Tcl_SetErrno(ENOENT);
	    return -1;
	}

	if (fsPtr == &tclNativeFilesystem) {















	    ClientData cd;
	    ClientData oldcd = tsdPtr->cwdClientData;

	    /*
	     * Assume that the native filesystem has a getCwdProc and that it
	     * is at version 2.
	     */

	    TclFSGetCwdProc2 *proc2 = (TclFSGetCwdProc2 *) fsPtr->getCwdProc;

	    cd = proc2(oldcd);
	    if (cd != oldcd) {
		/*
		 * Call getCwdProc() and store the resulting internal handle to
		 * compare things with it later.  This might might not be
		 * exactly the same string as that of the fully normalized
		 * pathname.  For example, for the Windows internal handle the
		 * separator is the backslash character.  On Unix it might well
		 * be true that the internal handle is the fully normalized
		 * pathname and one could simply use:
		 *	cd = Tcl_FSGetNativePath(pathPtr);
		 * but this can't be guaranteed in the general case.  In fact,
		 * the internal handle could be any value the filesystem
		 * decides to use to identify a node.
		 */

		FsUpdateCwd(normDirName, cd);
	    } 
	} else {
	    /*
	     * Tcl_FSGetCwd() synchronizes the file-global cwdPathPtr if
	     * needed.  However, if there is no 'getCwdProc', cwdPathPtr must be
	     * updated right now because there won't be another chance.  This
	     * block of code is currently executed whether or not the
	     * filesystem provides a getCwdProc, but it should in principle
	     * work to only call this block if fsPtr->getCwdProc == NULL.
	     */

	    FsUpdateCwd(normDirName, NULL);
	}

	if (oldFsPtr != NULL && fsPtr != oldFsPtr) {
	    /*

	     * The filesystem of the current directory is not the same as the
	     * filesystem of the previous current directory.  Invalidate All
	     * FsPath objects.
	     */

	    Tcl_FSMountsChanged(NULL);
	}
    } else {
	/*
	 * The current directory is now changed or an error occurred and an
	 * error message is now set. Just continue.
	 */
    }

    return retVal;
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSLoadFile --
 *
 *	Loads a dynamic shared object by passing the given pathname unmodified
 *	to Tcl_LoadFile, and provides pointers to the functions named by 'sym1'
 *	and 'sym2', and another pointer to a function that unloads the object.

 *







 * Results:
 *	A standard Tcl completion code. If an error occurs, sets the

 *	interpreter's result to an error message.
 *
 * Side effects:


 *	A dynamic shared object is loaded into memory.  This may later be
 *	unloaded by passing the handlePtr to *unloadProcPtr.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_FSLoadFile(
    Tcl_Interp *interp,		/* Used for error reporting. */
    Tcl_Obj *pathPtr,		/* Pathname of the file containing the dynamic shared object.
				 */
    const char *sym1, const char *sym2,
				/* Names of two functions to find in the
				 * dynamic shared object. */
    Tcl_PackageInitProc **proc1Ptr, Tcl_PackageInitProc **proc2Ptr,
				/* Places to store pointers to the functions
				 * named by sym1 and sym2. */
    Tcl_LoadHandle *handlePtr,	/* A place to store the token for the loaded
				 * object.  Can be passed to 
				 * (*unloadProcPtr)() to unload the file. */
    Tcl_FSUnloadFileProc **unloadProcPtr)
				/* A place to store a pointer to the function
				 * that unloads the object. */

{
    const char *symbols[3];
    void *procPtrs[2];
    int res;





    symbols[0] = sym1;
    symbols[1] = sym2;
    symbols[2] = NULL;





    res = Tcl_LoadFile(interp, pathPtr, symbols, 0, procPtrs, handlePtr);
    if (res == TCL_OK) {
	*proc1Ptr = (Tcl_PackageInitProc *) procPtrs[0];
	*proc2Ptr = (Tcl_PackageInitProc *) procPtrs[1];
    } else {
	*proc1Ptr = *proc2Ptr = NULL;
    }
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_LoadFile --
 *
 *	Load a dynamic shared object by calling 'loadFileProc' of the
 *	filesystem corresponding to the given pathname, and then finds within
 *	the loaded object the functions named in symbols[].  

 *
 *	The given pathname is passed unmodified to `loadFileProc`, which
 *	decides how to resolve it.  On POSIX systems the native filesystem
 *	passes the given pathname to dlopen(), which resolves the filename

 *	according to its own set of rules.  This behaviour is not very
 *	compatible with virtual filesystems, and has other problems as
 *	documented for [load], so it is recommended to use an absolute
 *	pathname.
 *
 * Results:
 *	A standard Tcl completion code. If an error occurs, sets the
 *	interpreter result to an error message.
 *
 * Side effects:
 *	Memory is allocated for the new object. May be freed by calling
 *	TclFS_UnloadFile.
 *
 *----------------------------------------------------------------------
 */

/*
 * Modern HPUX allows the unlink (no ETXTBSY error) yet somehow trashes some
 * internal data structures, preventing any additional dynamic shared objects
 * from getting properly loaded. Only the first is ok.  Work around the issue
 * by not unlinking, i.e., emulating the behaviour of the older HPUX which
 * denied removal.
 *
 * Doing the unlink is also an issue within docker containers, whose AUFS
 * bungles this as well, see
 *     https://github.com/dotcloud/docker/issues/1911
 *









 */

static int
skipUnlink(
    Tcl_Obj *shlibFile)
{
    /*
     * Unlinking is not performed in the following cases:

     *

     * 1. The operating system is HPUX.
     *
     * 2.   If the environment variable TCL_TEMPLOAD_NO_UNLINK is present and
     * set to true (an integer > 0)

     *


     * 3. TCL_TEMPLOAD_NO_UNLINK is not true (an integer > 0) and AUFS filesystem can be detected (using statfs, if available).
     *


     */


#ifdef hpux
    return 1;
#else
    char *skipstr = getenv("TCL_TEMPLOAD_NO_UNLINK");

    if (skipstr && (skipstr[0] != '\0')) {
	return atoi(skipstr);
    }

#ifdef TCL_TEMPLOAD_NO_UNLINK
/* At built time TCL_TEMPLOAD_NO_UNLINK can be set manually to control whether
 * this automatic overriding of unlink is included.
 */
#ifndef NO_FSTATFS
    {
	struct statfs fs;
	/*
	 * Have fstatfs. May not have the AUFS super magic ... Indeed our build
	 * box is too old to have it directly in the headers. Define taken from
	 *     http://mooon.googlecode.com/svn/trunk/linux_include/linux/aufs_type.h
	 *     http://aufs.sourceforge.net/
	 * Better reference will be gladly accepted.
	 */
#ifndef AUFS_SUPER_MAGIC
/* AUFS_SUPER_MAGIC can disable/override the AUFS detection, i.e. for
 * testing if a newer AUFS does not have the bug any more.
*/
#define AUFS_SUPER_MAGIC ('a' << 24 | 'u' << 16 | 'f' << 8 | 's')
#endif /* AUFS_SUPER_MAGIC */
	if ((statfs(Tcl_GetString(shlibFile), &fs) == 0)
		&& (fs.f_type == AUFS_SUPER_MAGIC)) {
	    return 1;
	}
    }
#endif /* ... NO_FSTATFS */
#endif /* ... TCL_TEMPLOAD_NO_UNLINK */

    /*
     * No HPUX, environment variable override, or AUFS detected.  Perform
     * unlink.
     */
    return 0;
#endif /* hpux */
}

int
Tcl_LoadFile(
    Tcl_Interp *interp,		/* Used for error reporting. */
    Tcl_Obj *pathPtr,		/* Pathname of the file containing the dynamic
				 * shared object. */
    const char *const symbols[],/* A null-terminated array of names of
				 * functions to find in the loaded object. */
    int flags,			/* Flags */
    void *procVPtrs,		/* A place to store pointers to the functions
				 *  named by symbols[]. */
    Tcl_LoadHandle *handlePtr)	/* A place to hold a token for the loaded object.

				 * Can be used by TclpFindSymbol. */
{
    void **procPtrs = (void **) procVPtrs;
    const Tcl_Filesystem *fsPtr = Tcl_FSGetFileSystemForPath(pathPtr);
    const Tcl_Filesystem *copyFsPtr;
    Tcl_FSUnloadFileProc *unloadProcPtr;
    Tcl_Obj *copyToPtr;
    Tcl_LoadHandle newLoadHandle = NULL;
................................................................................
	}
	if (Tcl_GetErrno() != EXDEV) {
	    return retVal;
	}
    }

    /*
     * The filesystem doesn't support 'load'. Fall to the following: 
     */


    /*
     * Make sure the file is accessible.
     */

    if (Tcl_FSAccess(pathPtr, R_OK) != 0) {
	if (interp) {
	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		    "couldn't load library \"%s\": %s",
		    Tcl_GetString(pathPtr), Tcl_PosixError(interp)));
	}
	return TCL_ERROR;
    }

#ifdef TCL_LOAD_FROM_MEMORY
    /*
     * The platform supports loading a dynamic shared object from memory.
     * Create a sufficiently large buffer, read the file into it, and then load
     * the dynamic shared object from the buffer:
     */

    {
	int ret, size;
	void *buffer;
	Tcl_StatBuf statBuf;
	Tcl_Channel data;
................................................................................
	ret = Tcl_FSStat(pathPtr, &statBuf);
	if (ret < 0) {
	    goto mustCopyToTempAnyway;
	}
	size = (int) statBuf.st_size;

	/*
	 * Tcl_Read takes an int:  Determine whether the file size is wide.
	 */

	if (size != (Tcl_WideInt) statBuf.st_size) {
	    goto mustCopyToTempAnyway;
	}
	data = Tcl_FSOpenFileChannel(interp, pathPtr, "rb", 0666);
	if (!data) {
................................................................................
  mustCopyToTempAnyway:
    if (interp) {
	Tcl_ResetResult(interp);
    }
#endif /* TCL_LOAD_FROM_MEMORY */

    /*
     * Get a temporary filename, first to copy the file into, and then to load.

     */

    copyToPtr = TclpTempFileNameForLibrary(interp, pathPtr);
    if (copyToPtr == NULL) {
	return TCL_ERROR;
    }
    Tcl_IncrRefCount(copyToPtr);

    copyFsPtr = Tcl_FSGetFileSystemForPath(copyToPtr);
    if ((copyFsPtr == NULL) || (copyFsPtr == fsPtr)) {
	/*
	 * Tcl_FSLoadFile isn't available for the filesystem of the temporary
	 * file.  In order to avoid a possible infinite loop, do not attempt to
	 * load further.
	 */

	 /*
	  * Try to delete the file we probably created and then exit.
	  */

	Tcl_FSDeleteFile(copyToPtr);
	Tcl_DecrRefCount(copyToPtr);
	if (interp) {
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "couldn't load from current filesystem", -1));
	}
	return TCL_ERROR;
    }

    if (TclCrossFilesystemCopy(interp, pathPtr, copyToPtr) != TCL_OK) {




	Tcl_FSDeleteFile(copyToPtr);
	Tcl_DecrRefCount(copyToPtr);
	return TCL_ERROR;
    }

#ifndef _WIN32
    /*
     * It might be necessary on some systems to set the appropriate permissions
     * on the file.  On Unix we could loop over the file attributes and set any
     * that are called "-permissions" to 0700, but just do it directly instead:

     */

    {
	int index;
	Tcl_Obj *perm;

	TclNewLiteralStringObj(perm, "0700");
................................................................................
	    Tcl_FSFileAttrsSet(NULL, index, copyToPtr, perm);
	}
	Tcl_DecrRefCount(perm);
    }
#endif

    /*
     * The cross-filesystem copy may have stored the number of bytes in the
     * result, so reset the result now.
     */

    if (interp) {
	Tcl_ResetResult(interp);
    }

    retVal = Tcl_LoadFile(interp, copyToPtr, symbols, flags, procPtrs,
	    &newLoadHandle);
    if (retVal != TCL_OK) {




	Tcl_FSDeleteFile(copyToPtr);
	Tcl_DecrRefCount(copyToPtr);
	return retVal;
    }

    /*
     * Try to delete the file immediately.  Some operatings systems allow this,
     * and it avoids leaving the copy laying around after exit.
     */

    if (!skipUnlink(copyToPtr) &&
	    (Tcl_FSDeleteFile(copyToPtr) == TCL_OK)) {
	Tcl_DecrRefCount(copyToPtr);

	/*

	 * Tell the caller all the details:  The package list maintained by
	 * 'load' stores the original (vfs) pathname, the handle of object
	 * loaded from the temporary file, and the unloadProcPtr.

	 */

	*handlePtr = newLoadHandle;
	if (interp) {
	    Tcl_ResetResult(interp);
	}
	return TCL_OK;
    }

    /*

     * Divert the unloading in order to unload and cleanup the temporary file.
     */

    tvdlPtr = ckalloc(sizeof(FsDivertLoad));

    /*
     * Remember three pieces of information in order to clean up the diverted
     * load completely on platforms which allow proper unloading of code.

     */

    tvdlPtr->loadHandle = newLoadHandle;
    tvdlPtr->unloadProcPtr = newUnloadProcPtr;

    if (copyFsPtr != &tclNativeFilesystem) {

	/* refCount of copyToPtr is already incremented.  */


	tvdlPtr->divertedFile = copyToPtr;

	/*
	 * This is the filesystem for the temporary file the object was loaded
	 * from.  A reference to copyToPtr is already stored in
	 * tvdlPtr->divertedFile, so need need to increment the refCount again. 
	 */

	tvdlPtr->divertedFilesystem = copyFsPtr;
	tvdlPtr->divertedFileNativeRep = NULL;
    } else {
	/*
	 * Grab the native representation.
	 */

	tvdlPtr->divertedFileNativeRep = TclNativeDupInternalRep(
		Tcl_FSGetInternalRep(copyToPtr, copyFsPtr));

	/*
	 * Don't keeep a reference to the Tcl_Obj or the native filesystem.

	 */

	tvdlPtr->divertedFile = NULL;
	tvdlPtr->divertedFilesystem = NULL;
	Tcl_DecrRefCount(copyToPtr);
    }

................................................................................
    if (interp) {
	Tcl_ResetResult(interp);
    }
    return retVal;

  resolveSymbols:
    /*
     * handlePtr now contains a token for the loaded object.
     * Resolve the symbols.
     */

    if (symbols != NULL) {
	for (i=0 ; symbols[i] != NULL; i++) {
	    procPtrs[i] = Tcl_FindSymbol(interp, *handlePtr, symbols[i]);
	    if (procPtrs[i] == NULL) {
		/*
		 * At least one symbol in the list was not found.  Unload the
		 * file and return an error code.  Tcl_FindSymbol should have
		 * already left an appropriate error message.

		 */

		(*handlePtr)->unloadFileProcPtr(*handlePtr);
		*handlePtr = NULL;
		return TCL_ERROR;
	    }
	}
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * DivertFindSymbol --
 *
 *	Find a symbol in a shared library loaded by making a copying a file
 *	from the virtual filesystem to a native filesystem.
 *
 *----------------------------------------------------------------------
 */

static void *
DivertFindSymbol(
    Tcl_Interp *interp, 	/* The relevant interpreter. */
    Tcl_LoadHandle loadHandle,	/* A handle to the diverted module. */
    const char *symbol)		/* The name of symbol to resolve. */
{
    FsDivertLoad *tvdlPtr = (FsDivertLoad *) loadHandle->clientData;
    Tcl_LoadHandle originalHandle = tvdlPtr->loadHandle;

    return originalHandle->findSymbolProcPtr(interp, originalHandle, symbol);
}
 
/*
 *----------------------------------------------------------------------
 *
 * DivertUnloadFile --
 *
 *	Unloads an object that was loaded from a temporary file copied from the
 *	virtual filesystem the native filesystem.



 *
 *----------------------------------------------------------------------
 */

static void
DivertUnloadFile(
    Tcl_LoadHandle loadHandle)	/* A handle for the loaded object. */
{
    FsDivertLoad *tvdlPtr = (FsDivertLoad *) loadHandle->clientData;
    Tcl_LoadHandle originalHandle;

    if (tvdlPtr == NULL) {
	/*

	 * tvdlPtr was provided by Tcl_LoadFile so it should not be NULL here.
	 */


	return;
    }
    originalHandle = tvdlPtr->loadHandle;

    /*
     * Call the real 'unloadfile' proc.  This must be called first so that the

     * shared library is actually unloaded by the OS. Otherwise, the following
     * 'delete' may fail because the shared library is still in use.
     */

    originalHandle->unloadFileProcPtr(originalHandle);

    /*
     * Determine which filesystem contains the temporary copy of the file.
     */

    if (tvdlPtr->divertedFilesystem == NULL) {
	/*
	 * Use the function for the native filsystem, which works works even at

	 * this late stage.
	 */

	TclpDeleteFile(tvdlPtr->divertedFileNativeRep);
	NativeFreeInternalRep(tvdlPtr->divertedFileNativeRep);
    } else {
	/*
	 * Remove the temporary file.  If encodings have been cleaned up
	 * already, this may crash.
	 */

	if (tvdlPtr->divertedFilesystem->deleteFileProc(tvdlPtr->divertedFile)
		!= TCL_OK) {
	    /*
	     * This may have happened because Tcl is exiting, and encodings may
	     * have already been deleted or something else the filesystem
	     * depends on may be gone.
	     *
	     * TO DO:  Figure out how to delete this file more robustly, or
	     * give the filesystem the information it needs to delete the file


	     * more robustly.  One problem might be that the filesystem cannot
	     * extract the information it needs from the above pathname object
	     * because Tcl's entire filesystem apparatus (the code in this
	     * file) has been finalized and there is no way to get the native

	     * handle of the file.
	     */
	}

	/*
	 * This also decrements the refCount of the Tcl_Filesystem
	 * corresponding to this file. which might cause the filesystem to be
	 * deallocated if Tcl is exiting.
	 */

	Tcl_DecrRefCount(tvdlPtr->divertedFile);
    }

    ckfree(tvdlPtr);
    ckfree(loadHandle);
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FindSymbol --
 *
 *	Find a symbol in a loaded object.
 *
 *	Previously filesystem-specific, but has been made portable by having
 *	TclpDlopen return a structure that includes procedure pointers.
 *
 * Results:
 *	Returns a pointer to the symbol if found.  Otherwise, sets
 *	an error message in the interpreter result and returns NULL.
 *
 *----------------------------------------------------------------------
 */

void *
Tcl_FindSymbol(
    Tcl_Interp *interp,		/* The relevant interpreter. */
    Tcl_LoadHandle loadHandle,	/* A handle for the loaded object. */
    const char *symbol)		/* The name name of the symbol to resolve. */
{
    return loadHandle->findSymbolProcPtr(interp, loadHandle, symbol);
}
 
/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSUnloadFile --
 *
 *	Unloads a loaded  object if unloading is supported for the object.

 *
 *----------------------------------------------------------------------
 */

int
Tcl_FSUnloadFile(
    Tcl_Interp *interp,		/* The relevant interpreter. */
    Tcl_LoadHandle handle)	/* A handle for the object to unload. */
{
    if (handle->unloadFileProcPtr == NULL) {
	if (interp != NULL) {
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "cannot unload: filesystem does not support unloading",
		    -1));
	}
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * TclFSUnloadTempFile --
 *
 *	Unloads an object loaded via temporary file from a virtual filesystem
 *	to a native filesystem.

 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Frees resources for the loaded object and deletes the temporary file.

 *
 *----------------------------------------------------------------------
 */

void
TclFSUnloadTempFile(
    Tcl_LoadHandle loadHandle)	/* A handle for the object, as provided by a
				 *  previous call to Tcl_FSLoadFile(). */

{
    FsDivertLoad *tvdlPtr = (FsDivertLoad *) loadHandle;

    if (tvdlPtr == NULL) {
	/*

	 * tvdlPtr was provided by Tcl_LoadFile so it should not be NULL here.
	 */


	return;
    }

    if (tvdlPtr->unloadProcPtr != NULL) {
	/*

	 * 'unloadProcPtr' must be called first so that the shared library is
	 * actually unloaded by the OS. Otherwise, the following 'delete' may
	 * well fail because the shared library is still in use.
	 */


	tvdlPtr->unloadProcPtr(tvdlPtr->loadHandle);
    }

    if (tvdlPtr->divertedFilesystem == NULL) {
	/*
	 * Call the function for the native fileystem, which works even at this

	 * late stage.
	 */

	TclpDeleteFile(tvdlPtr->divertedFileNativeRep);
	NativeFreeInternalRep(tvdlPtr->divertedFileNativeRep);
    } else {
	/*
	 * Remove the temporary file that was created.  If encodings have
	 * already been freed because the interpreter is exiting this may
	 * crash.
	 */

	if (tvdlPtr->divertedFilesystem->deleteFileProc(tvdlPtr->divertedFile)
		!= TCL_OK) {
	    /*
	     * This may have happened because Tcl is exiting and encodings may
	     * have already been deleted, or something else the filesystem
	     * depends on may be gone.
	     *
	     * TO DO:  Figure out how to delete this file more robustly, or
	     * give the filesystem the information it needs to delete the file


	     * more robustly.  One problem might be that the filesystem cannot
	     * extract the information it needs from the above pathname object
	     * because Tcl's entire filesystem apparatus (the code in this
	     * file) has been finalized and there is no way to get the native

	     * handle of the file.
	     */
	}

	/*
	 * This also decrements the refCount of the Tcl_Filesystem
	 * corresponding to this file. which might case filesystem to be freed
	 * if Tcl is exiting.
	 */

	Tcl_DecrRefCount(tvdlPtr->divertedFile);
    }

    ckfree(tvdlPtr);
}
 
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSLink --
 *
 *	Creates or inspects a link by calling 'linkProc' of the filesystem
 *	corresponding to the given pathname.  Replaces the library version of

 *	readlink().
 *
 * Results:
 *	If toPtr is NULL, a Tcl_Obj containing the value the symbolic link for
 *	'pathPtr', or NULL if a symbolic link was not accessible.  The caller
 *	should Tcl_DecrRefCount on the result to release it.  Otherwise NULL.

 *

 *	In this case the result has no additional reference count and need not
 *	be freed. The actual action to perform is given by the 'linkAction'

 *	flags, which is a combination of:
 *
 *		TCL_CREATE_SYMBOLIC_LINK
 *		TCL_CREATE_HARD_LINK
 *
 *	Most filesystems do not support linking across to different
 *	filesystems, so this function usually fails if the filesystem
 *	corresponding to toPtr is not the same as the filesystem corresponding
 *	to pathPtr.
 *
 * Side effects:
 *	Creates or sets a link if toPtr is not NULL.
 *
 *	See readlink().
 *
 *---------------------------------------------------------------------------
 */

Tcl_Obj *
Tcl_FSLink(
    Tcl_Obj *pathPtr,		/* Pathaname of file. */
    Tcl_Obj *toPtr,		/* 
				 * NULL or the pathname of a file to link to.
				 */
    int linkAction)		/* Action to perform. */
{
    const Tcl_Filesystem *fsPtr = Tcl_FSGetFileSystemForPath(pathPtr);

    if (fsPtr != NULL && fsPtr->linkProc != NULL) {
	return fsPtr->linkProc(pathPtr, toPtr, linkAction);
    }

    /*
     * If S_IFLNK isn't defined the machine doesn't support symbolic links, so
     * the file can't possibly be a symbolic link. Generate an EINVAL error,
     * which is what happens on machines that do support symbolic links when
     * readlink is called for a file that isn't a symbolic link.

     */

#ifndef S_IFLNK
    errno = EINVAL; /* TODO: Change to Tcl_SetErrno()? */
#else
    Tcl_SetErrno(ENOENT);
#endif /* S_IFLNK */
................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSListVolumes --
 *
 *	Lists the currently mounted volumes by calling `listVolumesProc` of
 *	each registered filesystem, and combining the results to form a list of
 *	volumes.







 *
 * Results:
 *	The list of volumes, in an object which has refCount 0.
 *
 * Side effects:
 *	None
 *
................................................................................
Tcl_Obj *
Tcl_FSListVolumes(void)
{
    FilesystemRecord *fsRecPtr;
    Tcl_Obj *resultPtr = Tcl_NewObj();

    /*
     * Call each "listVolumes" function of each registered filesystem in
     * succession. A non-NULL return value indicates the particular function
     * has succeeded.

     */

    fsRecPtr = FsGetFirstFilesystem();
    Claim();
    while (fsRecPtr != NULL) {
	if (fsRecPtr->fsPtr->listVolumesProc != NULL) {
	    Tcl_Obj *thisFsVolumes = fsRecPtr->fsPtr->listVolumesProc();

	    if (thisFsVolumes != NULL) {
		Tcl_ListObjAppendList(NULL, resultPtr, thisFsVolumes);
		/* The refCount of each list returned by a `listVolumesProc` is
		 * already incremented.  Do not hang onto the list, though.  It
		 * belongs to the filesystem.  Add its contents to * the result
		 * we are building, and then decrement the refCount.  */
		Tcl_DecrRefCount(thisFsVolumes);
	    }
	}
	fsRecPtr = fsRecPtr->nextPtr;
    }
    Disclaim();

................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * FsListMounts --
 *
 *	Lists the mounts mathing the given pattern in the given directory. 

 *
 * Results:
 *	A list, having a refCount of 0, of the matching mounts, or NULL if no
 *	search was performed because no filesystem provided a search routine.

 *
 * Side effects:
 *	None.
 *
 *---------------------------------------------------------------------------
 */

static Tcl_Obj *
FsListMounts(
    Tcl_Obj *pathPtr,		/* Pathname of directory to search. */
    const char *pattern)	/* Pattern to match against. */
{
    FilesystemRecord *fsRecPtr;
    Tcl_GlobTypeData mountsOnly = { TCL_GLOB_TYPE_MOUNT, 0, NULL, NULL };
    Tcl_Obj *resultPtr = NULL;

    /*
     * Call the matchInDirectory function of each registered filesystem,
     * passing it 'mountsOnly'.  Results accumulate in resultPtr.


     */

    fsRecPtr = FsGetFirstFilesystem();
    Claim();
    while (fsRecPtr != NULL) {
	if (fsRecPtr->fsPtr != &tclNativeFilesystem &&
		fsRecPtr->fsPtr->matchInDirectoryProc != NULL) {
................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSSplitPath --
 *
 *	Splits a pathname into its components.


 *
 * Results:
 *	A list with refCount of zero.


 *
 * Side effects:

 *	If lenPtr is not null, sets it to the number of elements in the result.
 *
 *---------------------------------------------------------------------------
 */

Tcl_Obj *
Tcl_FSSplitPath(
    Tcl_Obj *pathPtr,		/* The pathname to split. */
    int *lenPtr)		/* A place to hold the number of pathname
				 * elements. */
{
    Tcl_Obj *result = NULL;	/* Just to squelch gcc warnings. */
    const Tcl_Filesystem *fsPtr;
    char separator = '/';
    int driveNameLength;
    const char *p;

    /*
     * Perform platform-specific splitting.
     */

    if (TclFSGetPathType(pathPtr, &fsPtr,
	    &driveNameLength) == TCL_PATH_ABSOLUTE) {
	if (fsPtr == &tclNativeFilesystem) {
	    return TclpNativeSplitPath(pathPtr, lenPtr);
	}
    } else {
	return TclpNativeSplitPath(pathPtr, lenPtr);
    }

    /* Assume each separator is a single character. */



    if (fsPtr->filesystemSeparatorProc != NULL) {
	Tcl_Obj *sep = fsPtr->filesystemSeparatorProc(pathPtr);

	if (sep != NULL) {
	    Tcl_IncrRefCount(sep);
	    separator = Tcl_GetString(sep)[0];
	    Tcl_DecrRefCount(sep);
	}
    }

    /*
     * Add the drive name as first element of the result. The drive name may
     * contain strange characters like colons and sequences of forward slashes
     * For example, 'ftp://' is a valid drive name.
     */

    result = Tcl_NewObj();
    p = Tcl_GetString(pathPtr);
    Tcl_ListObjAppendElement(NULL, result,
	    Tcl_NewStringObj(p, driveNameLength));
    p += driveNameLength;

    /*
     * Add the remaining pathname elements to the list.
     */

    for (;;) {
	const char *elementStart = p;
	int length;

	while ((*p != '\0') && (*p != separator)) {
................................................................................
	    Tcl_ListObjAppendElement(NULL, result, nextElt);
	}
	if (*p++ == '\0') {
	    break;
	}
    }





    if (lenPtr != NULL) {
	TclListObjLength(NULL, result, lenPtr);
    }
    return result;
}
/*
 *----------------------------------------------------------------------
 *
 * TclGetPathType --
 *
 *	Helper function used by TclFSGetPathType and TclJoinPath.
 *
 * Results:
 *	One of TCL_PATH_ABSOLUTE, TCL_PATH_RELATIVE, or
 *	TCL_PATH_VOLUME_RELATIVE.


 *
 * Side effects:

 *	See **filesystemPtrptr, *driveNameLengthPtr and **driveNameRef,
 *
 *----------------------------------------------------------------------
 */

Tcl_PathType
TclGetPathType(
    Tcl_Obj *pathPtr,		/* Pathname to determine type of. */
    const Tcl_Filesystem **filesystemPtrPtr,
				/* If not NULL, a place in which to store a
				 * pointer to the filesystem for this pathname
				 * if it is absolute. */
    int *driveNameLengthPtr,	/* If not NULL, a place in which to store the
				 * length of the volume name. */

    Tcl_Obj **driveNameRef)	/* If not NULL, for an absolute pathname, a
				 * place to store a pointer to an object with a
				 * refCount of 1, and whose value is the name
				 * of the volume. */


{
    int pathLen;
    const char *path = TclGetStringFromObj(pathPtr, &pathLen);
    Tcl_PathType type;

    type = TclFSNonnativePathType(path, pathLen, filesystemPtrPtr,
	    driveNameLengthPtr, driveNameRef);
................................................................................
}
 
/*
 *----------------------------------------------------------------------
 *
 * TclFSNonnativePathType --
 *
 *	Helper function used by TclGetPathType. Checks whether the given
 *	pathname starts with a string which corresponds to a file volume in
 *	some registered filesystem other than the native one.  For speed and
 *	historical reasons the native filesystem has special hard-coded checks
 *	dotted here and there in the filesystem code.
 *
 * Results:
 *	One of TCL_PATH_ABSOLUTE or TCL_PATH_RELATIVE.  The filesystem
 *	reference will be set if and only if it is non-NULL and the function's
 *	return value is TCL_PATH_ABSOLUTE.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

Tcl_PathType
TclFSNonnativePathType(
    const char *path,		/* Pathname to determine the type of. */
    int pathLen,		/* Length of the pathname. */
    const Tcl_Filesystem **filesystemPtrPtr,
				/* If not NULL, a  place to store a pointer to
				 * the filesystem for this pathname when it is
				 * an absolute pathname. */
    int *driveNameLengthPtr,	/* If not NULL, a place to store the length of
				 * the volume name if the pathname is absolute.
				 */
    Tcl_Obj **driveNameRef)	/* If not NULL, a place to store a pointer to
				 * an object having its its refCount already
				 * incremented, and contining the name of the
				 * volume if the pathname is absolute. */

{
    FilesystemRecord *fsRecPtr;
    Tcl_PathType type = TCL_PATH_RELATIVE;

    /*
     * Determine whether the given pathname is an absolute pathname on some
     * filesystem other than the native filesystem.

     */

    fsRecPtr = FsGetFirstFilesystem();
    Claim();
    while (fsRecPtr != NULL) {
	/*
	 * Skip the the native filesystem because otherwise some of the tests
	 * in the Tcl testsuite might fail because some of the tests
	 * artificially change the current platform (between win, unix) but the
	 * list of volumes obtained by calling fsRecPtr->fsPtr->listVolumesProc
	 * reflects the current (real) platform only. In particular, on Unix

	 * '/' matchs the beginning of certain absolute Windows pathnames
	 * starting '//' and those tests go wrong.
	 *

	 * There is another reason to skip the native filesystem:  Since the
	 * tclFilename.c code has nice fast 'absolute path' checkers, there is


	 * no reason to waste time doing that in this frequently-called
	 * function.  It is better to save the overhead of the native

	 * filesystem continuously returning a list of volumes.
	 */

	if ((fsRecPtr->fsPtr != &tclNativeFilesystem)
		&& (fsRecPtr->fsPtr->listVolumesProc != NULL)) {
	    int numVolumes;
	    Tcl_Obj *thisFsVolumes = fsRecPtr->fsPtr->listVolumesProc();

	    if (thisFsVolumes != NULL) {
		if (Tcl_ListObjLength(NULL, thisFsVolumes, &numVolumes)
			!= TCL_OK) {
		    /*
		     * This is VERY bad; the listVolumesProc didn't return a
		     * valid list. Set numVolumes to -1 to skip the loop below
		     * and just return with the current value of 'type'.

		     *
		     * It would be better to signal an error here, but
		     * Tcl_Panic seems a bit excessive.
		     */

		    numVolumes = -1;
		}
		while (numVolumes > 0) {
		    Tcl_Obj *vol;
		    int len;
................................................................................
			}
			break;
		    }
		}
		Tcl_DecrRefCount(thisFsVolumes);
		if (type == TCL_PATH_ABSOLUTE) {
		    /*
		     * No need to to examine additional filesystems.
		     */

		    break;
		}
	    }
	}
	fsRecPtr = fsRecPtr->nextPtr;
................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSRenameFile --
 *
 *	If the two pathnames correspond to the same filesystem, call
 *	'renameFileProc' of that filesystem.  Otherwise return the POSIX error
 *	'EXDEV', and -1.
 *
 * Results:
 *	A standard Tcl error code if a rename function was called, or -1
 *	otherwise.
 *
 * Side effects:
 *	A file may be renamed.
 *
 *---------------------------------------------------------------------------
 */

int
Tcl_FSRenameFile(
    Tcl_Obj *srcPathPtr,	/* The pathname of a file or directory to be
				   renamed. */
    Tcl_Obj *destPathPtr)	/* The new pathname for the file. */

{
    int retVal = -1;
    const Tcl_Filesystem *fsPtr, *fsPtr2;

    fsPtr = Tcl_FSGetFileSystemForPath(srcPathPtr);
    fsPtr2 = Tcl_FSGetFileSystemForPath(destPathPtr);

................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSCopyFile --
 *
 *	If both pathnames correspond to the same filesystem, calls
 *	'copyFileProc' of that filesystem.

 *
 *	In the native filesystems, 'copyFileProc' copies a link itself, not the


 *	thing the link points to.
 *
 * Results:

 *	A standard Tcl return code if a copyFileProc was called, or -1
 *	otherwise.
 *
 * Side effects:
 *	A file might be copied.  The POSIX error 'EXDEV' is set if a copy
 *	function was not called.
 *
 *---------------------------------------------------------------------------
 */

int
Tcl_FSCopyFile(
    Tcl_Obj *srcPathPtr,	/* The pathname of file to be copied. */
    Tcl_Obj *destPathPtr)	/* The new pathname to copy the file to. */
{
    int retVal = -1;
    const Tcl_Filesystem *fsPtr, *fsPtr2;

    fsPtr = Tcl_FSGetFileSystemForPath(srcPathPtr);
    fsPtr2 = Tcl_FSGetFileSystemForPath(destPathPtr);

................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * TclCrossFilesystemCopy --
 *
 *	Helper for Tcl_FSCopyFile and Tcl_FSLoadFile.  Copies a file from one
 *	filesystem to another, overwiting any file that already exists. 

 *
 * Results:
 *	A standard Tcl return code.
 *
 * Side effects:
 *	A file may be copied.
 *
 *---------------------------------------------------------------------------
 */

int
TclCrossFilesystemCopy(
    Tcl_Interp *interp,		/* For error messages. */
    Tcl_Obj *source,		/* Pathname of file to be copied. */
    Tcl_Obj *target)		/* Pathname to copy the file to. */
{
    int result = TCL_ERROR;
    int prot = 0666;
    Tcl_Channel in, out;
    Tcl_StatBuf sourceStatBuf;
    struct utimbuf tval;

    out = Tcl_FSOpenFileChannel(interp, target, "wb", prot);
    if (out == NULL) {
	/*
	 * Failed to open an output channel.  Bail out.
	 */
	goto done;
    }

    in = Tcl_FSOpenFileChannel(interp, source, "rb", prot);
    if (in == NULL) {
	/*
	 * Could not open an input channel.  Why didn't the caller check this?
	 */

	Tcl_Close(interp, out);
	goto done;
    }

    /*
     * Copy the file synchronously.  TO DO:  Maybe add an asynchronous option
     * to support virtual filesystems that are slow (e.g. network sockets).
     */

    if (TclCopyChannel(interp, in, out, -1, NULL) == TCL_OK) {
	result = TCL_OK;
    }

    /*
     * If the copy failed, assume that copy channel left an error message.
     */

    Tcl_Close(interp, in);
    Tcl_Close(interp, out);

    /*
     * Set modification date of copied file.
................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSDeleteFile --
 *
 *	Calls 'deleteFileProc' of the filesystem corresponding to the given
 *	pathname.
 *
 * Results:
 *	A standard Tcl return code.
 *
 * Side effects:
 *	A file may be deleted.
 *
 *---------------------------------------------------------------------------
 */

................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSCreateDirectory --
 *
 *	Calls 'createDirectoryProc' of the filesystem corresponding to the
 *	given pathname.
 *
 * Results:
 *	A standard Tcl return code, or -1 if no createDirectoryProc is found.
 *
 * Side effects:
 *	A directory may be created.  POSIX error 'ENOENT' is set if no
 *	createDirectoryProc is found.
 *
 *---------------------------------------------------------------------------
 */

int
Tcl_FSCreateDirectory(
    Tcl_Obj *pathPtr)		/* Pathname of directory to create (UTF-8). */
................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSCopyDirectory --
 *
 *	If both pathnames correspond to the the same filesystem, calls
 *	'copyDirectoryProc' of that filesystem.

 *
 * Results:

 *	A standard Tcl return code, or -1 if no 'copyDirectoryProc' is found.
 *
 * Side effects:
 *	A directory may be copied. POSIX error 'EXDEV' is set if no
 *	copyDirectoryProc is found.
 *
 *---------------------------------------------------------------------------
 */

int
Tcl_FSCopyDirectory(
    Tcl_Obj *srcPathPtr,	/*
				 * The pathname of the directory to be copied.
				 */
    Tcl_Obj *destPathPtr,	/* The pathname of the target directory. */
    Tcl_Obj **errorPtr)		/* If not NULL, and there is an error, a place

				 *  to store a pointer to a new object, with
				 *  its refCount already incremented, and
				 *  containing the pathname name of file
				 *  causing the error. */
{
    int retVal = -1;
    const Tcl_Filesystem *fsPtr, *fsPtr2;

    fsPtr = Tcl_FSGetFileSystemForPath(srcPathPtr);
    fsPtr2 = Tcl_FSGetFileSystemForPath(destPathPtr);

................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSRemoveDirectory --
 *
 *	Calls 'removeDirectoryProc' of the filesystem corresponding to remove
 *	pathPtr.
 *
 * Results:
 *	A standard Tcl return code, or -1 if no removeDirectoryProc is found.
 *
 * Side effects:
 *	A directory may be removed.  POSIX error 'ENOENT' is set if no
 *	removeDirectoryProc is found.
 *
 *---------------------------------------------------------------------------
 */

int
Tcl_FSRemoveDirectory(
    Tcl_Obj *pathPtr,		/* The pathname of the directory to be removed.
                                 */
    int recursive,		/* If zero, removes only an empty directory.
				 * Otherwise, removes the directory and all its
				 * contents.  */
    Tcl_Obj **errorPtr)		/* If not NULL and an error occurs, stores a
				 * place to store a a pointer to a new
				 * object having a refCount of 1 and containing
				 * the name of the file that produced an error.
				 * */
{
    const Tcl_Filesystem *fsPtr = Tcl_FSGetFileSystemForPath(pathPtr);

    if (fsPtr == NULL || fsPtr->removeDirectoryProc == NULL) {
	Tcl_SetErrno(ENOENT);
	return -1;
    }






    if (recursive) {
	Tcl_Obj *cwdPtr = Tcl_FSGetCwd(NULL);

	if (cwdPtr != NULL) {
	    const char *cwdStr, *normPathStr;
	    int cwdLen, normLen;
	    Tcl_Obj *normPath = Tcl_FSGetNormalizedPath(NULL, pathPtr);

	    if (normPath != NULL) {
		normPathStr = TclGetStringFromObj(normPath, &normLen);
		cwdStr = TclGetStringFromObj(cwdPtr, &cwdLen);
		if ((cwdLen >= normLen) && (strncmp(normPathStr, cwdStr,
			(size_t) normLen) == 0)) {
		    /*
		     * The cwd is inside the directory to be removed.  Change
		     * the cwd to [file dirname $path].
		     */

		    Tcl_Obj *dirPtr = TclPathPart(NULL, pathPtr,
			    TCL_PATH_DIRNAME);

		    Tcl_FSChdir(dirPtr);
		    Tcl_DecrRefCount(dirPtr);
................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSGetFileSystemForPath --
 *
 *	Produces the filesystem that corresponds to the given pathname.



 *
 * Results:

 *	The corresponding Tcl_Filesystem, or NULL if the pathname is invalid.
 *
 * Side effects:

 *	The internal representation of fsPtrPtr is converted to fsPathType if
 *	needed, and that internal representation is updated as needed.
 *
 *---------------------------------------------------------------------------
 */

const Tcl_Filesystem *
Tcl_FSGetFileSystemForPath(
    Tcl_Obj *pathPtr)
................................................................................
    const Tcl_Filesystem *retVal = NULL;

    if (pathPtr == NULL) {
	Tcl_Panic("Tcl_FSGetFileSystemForPath called with NULL object");
	return NULL;
    }

    if (pathPtr->refCount == 0) {
	/*

	 * Avoid possible segfaults or nondeterministic memory leaks where the
	 * reference count has been incorreclty managed.
	 */


	Tcl_Panic("Tcl_FSGetFileSystemForPath called with object with refCount == 0");
	return NULL;
    }




    /* Start with an up-to-date copy of the master filesystem. */



    fsRecPtr = FsGetFirstFilesystem();
    Claim();

    /*
     * Ensure that pathPtr is a valid pathname.
     */
    if (TclFSEnsureEpochOk(pathPtr, &retVal) != TCL_OK) {
	/* not a valid pathname */
	Disclaim();
	return NULL;
    } else if (retVal != NULL) {
	/*
	 * Found the filesystem in the internal representation of pathPtr.
	*/
	Disclaim();
	return retVal;
    }

    /*
     * Call each of the "pathInFilesystem" functions in succession until the
     * corresponding filesystem is found.
     */ 

    for (; fsRecPtr!=NULL ; fsRecPtr=fsRecPtr->nextPtr) {
	ClientData clientData = NULL;

	if (fsRecPtr->fsPtr->pathInFilesystemProc == NULL) {
	    continue;
	}

	if (fsRecPtr->fsPtr->pathInFilesystemProc(pathPtr, &clientData)!=-1) {
	    /* This is the filesystem for pathPtr.  Assume the type of pathPtr
	     * hasn't been changed by the above call to the
	     * pathInFilesystemProc, and cache this result in the internal
	     * representation of pathPtr.  */

	    TclFSSetPathDetails(pathPtr, fsRecPtr->fsPtr, clientData);
	    Disclaim();
	    return fsRecPtr->fsPtr;
	}
    }
    Disclaim();
................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSGetNativePath --
 *



















 *  See Tcl_FSGetInternalRep.
 *
 *---------------------------------------------------------------------------
 */

const void *
Tcl_FSGetNativePath(
    Tcl_Obj *pathPtr)
................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * NativeFreeInternalRep --
 *
 *	Free a native internal representation.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Memory is released.
 *
................................................................................
    ckfree(clientData);
}
 
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSFileSystemInfo --
 *	Produce the type of a pathname and the type of its filesystem.
 *



 *
 * Results:
 *	A list where the first item is the name of the filesystem (e.g.
 *	"native" or "vfs"), and the second item is the type of the given
 *	pathname within that filesystem.
 *
 * Side effects:
 *	The internal representation of pathPtr may be converted to a
 *	fsPathType.
 *
 *---------------------------------------------------------------------------
 */

Tcl_Obj *
Tcl_FSFileSystemInfo(
    Tcl_Obj *pathPtr)
................................................................................
}
 
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSPathSeparator --
 *
 *	Produces the separator for given pathname.

 *
 * Results:



 *	A Tcl object having a refCount of zero.
 *
 * Side effects:
 *	The internal representation of pathPtr may be converted to a fsPathType
 *
 *---------------------------------------------------------------------------
 */

Tcl_Obj *
Tcl_FSPathSeparator(
    Tcl_Obj *pathPtr)
................................................................................
    }

    if (fsPtr->filesystemSeparatorProc != NULL) {
	return fsPtr->filesystemSeparatorProc(pathPtr);
    }

    /*
     * Use the standard forward slash character if filesystem does not to
     * provide a filesystemSeparatorProc.
     */

    TclNewLiteralStringObj(resultObj, "/");
    return resultObj;
}
 
/*
 *---------------------------------------------------------------------------
 *
 * NativeFilesystemSeparator --
 *
 *	This function, part of the native filesystem support, returns the
 *	separator for the given pathname.
 *
 * Results:
 *	The separator character.
 *
 * Side effects:
 *	None.
 *
 *---------------------------------------------------------------------------
 */

   mp_digit d2;
   mp_err result = TclBN_s_mp_div_d(a, b, c, (d ? &d2 : NULL));
   if (d) {
      *d = d2;
   }
   return result;
}
mp_err TclBN_mp_div_3(const mp_int *a, mp_int *c, unsigned int *d) {
   mp_digit d2;
   mp_err result = TclBN_s_mp_div_3(a, c, &d2);
   if (d) {
      *d = d2;
   }
   return result;
}
mp_err TclBN_mp_init_set(mp_int *a, unsigned int b) {
	return TclBN_s_mp_init_set(a, b);
}
mp_err	TclBN_mp_mul_d(const mp_int *a, unsigned int b, mp_int *c) {
	return TclBN_s_mp_mul_d(a, b, c);
}
void TclBN_mp_set(mp_int *a, unsigned int b) {
................................................................................


#if defined(TCL_NO_DEPRECATED) || TCL_MAJOR_VERSION > 8
#   define TclBN_mp_expt_d_ex 0
#   define TclBN_mp_to_unsigned_bin 0
#   define TclBN_mp_to_unsigned_bin_n 0
#   define TclBN_mp_toradix_n 0


#   define TclSetStartupScriptPath 0
#   define TclGetStartupScriptPath 0
#   define TclSetStartupScriptFileName 0
#   define TclGetStartupScriptFileName 0
#   define TclPrecTraceProc 0
#   define TclpInetNtoa 0
#   define TclWinGetServByName 0
................................................................................
#   define Tcl_SetIntObj 0
#   define Tcl_SetLongObj 0
#   define Tcl_NewIntObj 0
#   define Tcl_NewLongObj 0
#   define Tcl_DbNewLongObj 0
#   define Tcl_BackgroundError 0
#else










int TclBN_mp_expt_d_ex(const mp_int *a, unsigned int b, mp_int *c, int fast)
{
	return mp_expt_u32(a, b, c);
}

mp_err mp_to_unsigned_bin(const mp_int *a, unsigned char *b)

   mp_digit d2;
   mp_err result = TclBN_s_mp_div_d(a, b, c, (d ? &d2 : NULL));
   if (d) {
      *d = d2;
   }
   return result;
}








mp_err TclBN_mp_init_set(mp_int *a, unsigned int b) {
	return TclBN_s_mp_init_set(a, b);
}
mp_err	TclBN_mp_mul_d(const mp_int *a, unsigned int b, mp_int *c) {
	return TclBN_s_mp_mul_d(a, b, c);
}
void TclBN_mp_set(mp_int *a, unsigned int b) {
................................................................................


#if defined(TCL_NO_DEPRECATED) || TCL_MAJOR_VERSION > 8
#   define TclBN_mp_expt_d_ex 0
#   define TclBN_mp_to_unsigned_bin 0
#   define TclBN_mp_to_unsigned_bin_n 0
#   define TclBN_mp_toradix_n 0
#   define TclBN_mp_sqr 0
#   define TclBN_mp_div_3 0
#   define TclSetStartupScriptPath 0
#   define TclGetStartupScriptPath 0
#   define TclSetStartupScriptFileName 0
#   define TclGetStartupScriptFileName 0
#   define TclPrecTraceProc 0
#   define TclpInetNtoa 0
#   define TclWinGetServByName 0
................................................................................
#   define Tcl_SetIntObj 0
#   define Tcl_SetLongObj 0
#   define Tcl_NewIntObj 0
#   define Tcl_NewLongObj 0
#   define Tcl_DbNewLongObj 0
#   define Tcl_BackgroundError 0
#else

mp_err TclBN_mp_div_3(const mp_int *a, mp_int *c, unsigned int *d) {
   mp_digit d2;
   mp_err result = TclBN_s_mp_div_3(a, c, &d2);
   if (d) {
      *d = d2;
   }
   return result;
}

int TclBN_mp_expt_d_ex(const mp_int *a, unsigned int b, mp_int *c, int fast)
{
	return mp_expt_u32(a, b, c);
}

mp_err mp_to_unsigned_bin(const mp_int *a, unsigned char *b)

}
declare 15 {
    mp_err MP_WUR TclBN_mp_div_2(const mp_int *a, mp_int *q)
}
declare 16 {
    mp_err MP_WUR TclBN_mp_div_2d(const mp_int *a, int b, mp_int *q, mp_int *r)
}
declare 17 {
    mp_err MP_WUR TclBN_mp_div_3(const mp_int *a, mp_int *q, unsigned int *r)
}
declare 18 {
    void TclBN_mp_exch(mp_int *a, mp_int *b)
}
declare 19 {
    mp_err MP_WUR TclBN_mp_expt_u32(const mp_int *a, unsigned int b, mp_int *c)
................................................................................
}
declare 38 {
    mp_err MP_WUR TclBN_mp_shrink(mp_int *a)
}
declare 39 {
    void TclBN_mp_set(mp_int *a, unsigned int b)
}
declare 40 {
    mp_err MP_WUR TclBN_mp_sqr(const mp_int *a, mp_int *b)
}
declare 41 {
    mp_err MP_WUR TclBN_mp_sqrt(const mp_int *a, mp_int *b)
}
declare 42 {
    mp_err MP_WUR TclBN_mp_sub(const mp_int *a, const mp_int *b, mp_int *c)

}
declare 15 {
    mp_err MP_WUR TclBN_mp_div_2(const mp_int *a, mp_int *q)
}
declare 16 {
    mp_err MP_WUR TclBN_mp_div_2d(const mp_int *a, int b, mp_int *q, mp_int *r)
}
declare 17 {deprecated {is private function in libtommath}} {
    mp_err MP_WUR TclBN_mp_div_3(const mp_int *a, mp_int *q, unsigned int *r)
}
declare 18 {
    void TclBN_mp_exch(mp_int *a, mp_int *b)
}
declare 19 {
    mp_err MP_WUR TclBN_mp_expt_u32(const mp_int *a, unsigned int b, mp_int *c)
................................................................................
}
declare 38 {
    mp_err MP_WUR TclBN_mp_shrink(mp_int *a)
}
declare 39 {
    void TclBN_mp_set(mp_int *a, unsigned int b)
}
declare 40 {nostub {is private function in libtommath}} {
    mp_err MP_WUR TclBN_mp_sqr(const mp_int *a, mp_int *b)
}
declare 41 {
    mp_err MP_WUR TclBN_mp_sqrt(const mp_int *a, mp_int *b)
}
declare 42 {
    mp_err MP_WUR TclBN_mp_sub(const mp_int *a, const mp_int *b, mp_int *c)

#define mp_rshd TclBN_mp_rshd
#define mp_set_int(a,b) (MP_DEPRECATED_PRAGMA("replaced by mp_set_ul") (TclBN_mp_set_ul((a),((unsigned int)(b))),MP_OKAY))
#define mp_set_long(a,b) (MP_DEPRECATED_PRAGMA("replaced by mp_set_ul") (TclBN_mp_set_ul((a),(b)),MP_OKAY))
#define mp_set_long_long(a,b) (MP_DEPRECATED_PRAGMA("replaced by mp_set_ull") (TclBN_mp_set_ull((a),(b)),MP_OKAY))
#define mp_set_ul TclBN_mp_set_ul
#define mp_set_ull TclBN_mp_set_ull
#define mp_shrink TclBN_mp_shrink
#define mp_sqr TclBN_mp_sqr
#define mp_sqrt TclBN_mp_sqrt
#define mp_sub TclBN_mp_sub
#define mp_signed_rsh TclBN_mp_signed_rsh
#define mp_tc_and TclBN_mp_and
#define mp_tc_div_2d TclBN_mp_signed_rsh
#define mp_tc_or TclBN_mp_or
#define mp_tc_xor TclBN_mp_xor
................................................................................
				mp_int *q, unsigned int *r) MP_WUR;
/* 15 */
EXTERN mp_err		TclBN_mp_div_2(const mp_int *a, mp_int *q) MP_WUR;
/* 16 */
EXTERN mp_err		TclBN_mp_div_2d(const mp_int *a, int b, mp_int *q,
				mp_int *r) MP_WUR;
/* 17 */

EXTERN mp_err		TclBN_mp_div_3(const mp_int *a, mp_int *q,
				unsigned int *r) MP_WUR;
/* 18 */
EXTERN void		TclBN_mp_exch(mp_int *a, mp_int *b);
/* 19 */
EXTERN mp_err		TclBN_mp_expt_u32(const mp_int *a, unsigned int b,
				mp_int *c) MP_WUR;
/* 20 */
................................................................................
    mp_ord (*tclBN_mp_cmp_mag) (const mp_int *a, const mp_int *b) MP_WUR; /* 10 */
    mp_err (*tclBN_mp_copy) (const mp_int *a, mp_int *b) MP_WUR; /* 11 */
    int (*tclBN_mp_count_bits) (const mp_int *a) MP_WUR; /* 12 */
    mp_err (*tclBN_mp_div) (const mp_int *a, const mp_int *b, mp_int *q, mp_int *r) MP_WUR; /* 13 */
    mp_err (*tclBN_mp_div_d) (const mp_int *a, unsigned int b, mp_int *q, unsigned int *r) MP_WUR; /* 14 */
    mp_err (*tclBN_mp_div_2) (const mp_int *a, mp_int *q) MP_WUR; /* 15 */
    mp_err (*tclBN_mp_div_2d) (const mp_int *a, int b, mp_int *q, mp_int *r) MP_WUR; /* 16 */
    mp_err (*tclBN_mp_div_3) (const mp_int *a, mp_int *q, unsigned int *r) MP_WUR; /* 17 */
    void (*tclBN_mp_exch) (mp_int *a, mp_int *b); /* 18 */
    mp_err (*tclBN_mp_expt_u32) (const mp_int *a, unsigned int b, mp_int *c) MP_WUR; /* 19 */
    mp_err (*tclBN_mp_grow) (mp_int *a, int size) MP_WUR; /* 20 */
    mp_err (*tclBN_mp_init) (mp_int *a) MP_WUR; /* 21 */
    mp_err (*tclBN_mp_init_copy) (mp_int *a, const mp_int *b) MP_WUR; /* 22 */
    mp_err (*tclBN_mp_init_multi) (mp_int *a, ...) MP_WUR; /* 23 */
    mp_err (*tclBN_mp_init_set) (mp_int *a, unsigned int b) MP_WUR; /* 24 */
................................................................................
    mp_err (*tclBN_mp_neg) (const mp_int *a, mp_int *b) MP_WUR; /* 33 */
    mp_err (*tclBN_mp_or) (const mp_int *a, const mp_int *b, mp_int *c) MP_WUR; /* 34 */
    mp_err (*tclBN_mp_radix_size) (const mp_int *a, int radix, int *size) MP_WUR; /* 35 */
    mp_err (*tclBN_mp_read_radix) (mp_int *a, const char *str, int radix) MP_WUR; /* 36 */
    void (*tclBN_mp_rshd) (mp_int *a, int shift); /* 37 */
    mp_err (*tclBN_mp_shrink) (mp_int *a) MP_WUR; /* 38 */
    void (*tclBN_mp_set) (mp_int *a, unsigned int b); /* 39 */
    mp_err (*tclBN_mp_sqr) (const mp_int *a, mp_int *b) MP_WUR; /* 40 */
    mp_err (*tclBN_mp_sqrt) (const mp_int *a, mp_int *b) MP_WUR; /* 41 */
    mp_err (*tclBN_mp_sub) (const mp_int *a, const mp_int *b, mp_int *c) MP_WUR; /* 42 */
    mp_err (*tclBN_mp_sub_d) (const mp_int *a, unsigned int b, mp_int *c) MP_WUR; /* 43 */
    TCL_DEPRECATED_API("Use mp_to_ubin") mp_err (*tclBN_mp_to_unsigned_bin) (const mp_int *a, unsigned char *b); /* 44 */
    TCL_DEPRECATED_API("Use mp_to_ubin") mp_err (*tclBN_mp_to_unsigned_bin_n) (const mp_int *a, unsigned char *b, unsigned long *outlen); /* 45 */
    TCL_DEPRECATED_API("Use mp_to_radix") mp_err (*tclBN_mp_toradix_n) (const mp_int *a, char *str, int radix, int maxlen); /* 46 */
    size_t (*tclBN_mp_ubin_size) (const mp_int *a); /* 47 */
................................................................................
#define mp_mul_d TclBN_s_mp_mul_d
#define mp_set TclBN_s_mp_set
#define mp_expt_u32 TclBN_s_mp_expt_u32
#endif /* !BUILD_tcl */

#undef TCL_STORAGE_CLASS
#define TCL_STORAGE_CLASS DLLIMPORT







#endif /* _TCLINTDECLS */

#define mp_rshd TclBN_mp_rshd
#define mp_set_int(a,b) (MP_DEPRECATED_PRAGMA("replaced by mp_set_ul") (TclBN_mp_set_ul((a),((unsigned int)(b))),MP_OKAY))
#define mp_set_long(a,b) (MP_DEPRECATED_PRAGMA("replaced by mp_set_ul") (TclBN_mp_set_ul((a),(b)),MP_OKAY))
#define mp_set_long_long(a,b) (MP_DEPRECATED_PRAGMA("replaced by mp_set_ull") (TclBN_mp_set_ull((a),(b)),MP_OKAY))
#define mp_set_ul TclBN_mp_set_ul
#define mp_set_ull TclBN_mp_set_ull
#define mp_shrink TclBN_mp_shrink

#define mp_sqrt TclBN_mp_sqrt
#define mp_sub TclBN_mp_sub
#define mp_signed_rsh TclBN_mp_signed_rsh
#define mp_tc_and TclBN_mp_and
#define mp_tc_div_2d TclBN_mp_signed_rsh
#define mp_tc_or TclBN_mp_or
#define mp_tc_xor TclBN_mp_xor
................................................................................
				mp_int *q, unsigned int *r) MP_WUR;
/* 15 */
EXTERN mp_err		TclBN_mp_div_2(const mp_int *a, mp_int *q) MP_WUR;
/* 16 */
EXTERN mp_err		TclBN_mp_div_2d(const mp_int *a, int b, mp_int *q,
				mp_int *r) MP_WUR;
/* 17 */
TCL_DEPRECATED("is private function in libtommath")
mp_err MP_WUR		TclBN_mp_div_3(const mp_int *a, mp_int *q,
				unsigned int *r) MP_WUR;
/* 18 */
EXTERN void		TclBN_mp_exch(mp_int *a, mp_int *b);
/* 19 */
EXTERN mp_err		TclBN_mp_expt_u32(const mp_int *a, unsigned int b,
				mp_int *c) MP_WUR;
/* 20 */
................................................................................
    mp_ord (*tclBN_mp_cmp_mag) (const mp_int *a, const mp_int *b) MP_WUR; /* 10 */
    mp_err (*tclBN_mp_copy) (const mp_int *a, mp_int *b) MP_WUR; /* 11 */
    int (*tclBN_mp_count_bits) (const mp_int *a) MP_WUR; /* 12 */
    mp_err (*tclBN_mp_div) (const mp_int *a, const mp_int *b, mp_int *q, mp_int *r) MP_WUR; /* 13 */
    mp_err (*tclBN_mp_div_d) (const mp_int *a, unsigned int b, mp_int *q, unsigned int *r) MP_WUR; /* 14 */
    mp_err (*tclBN_mp_div_2) (const mp_int *a, mp_int *q) MP_WUR; /* 15 */
    mp_err (*tclBN_mp_div_2d) (const mp_int *a, int b, mp_int *q, mp_int *r) MP_WUR; /* 16 */
    TCL_DEPRECATED_API("is private function in libtommath") mp_err (*tclBN_mp_div_3) (const mp_int *a, mp_int *q, unsigned int *r) MP_WUR; /* 17 */
    void (*tclBN_mp_exch) (mp_int *a, mp_int *b); /* 18 */
    mp_err (*tclBN_mp_expt_u32) (const mp_int *a, unsigned int b, mp_int *c) MP_WUR; /* 19 */
    mp_err (*tclBN_mp_grow) (mp_int *a, int size) MP_WUR; /* 20 */
    mp_err (*tclBN_mp_init) (mp_int *a) MP_WUR; /* 21 */
    mp_err (*tclBN_mp_init_copy) (mp_int *a, const mp_int *b) MP_WUR; /* 22 */
    mp_err (*tclBN_mp_init_multi) (mp_int *a, ...) MP_WUR; /* 23 */
    mp_err (*tclBN_mp_init_set) (mp_int *a, unsigned int b) MP_WUR; /* 24 */
................................................................................
    mp_err (*tclBN_mp_neg) (const mp_int *a, mp_int *b) MP_WUR; /* 33 */
    mp_err (*tclBN_mp_or) (const mp_int *a, const mp_int *b, mp_int *c) MP_WUR; /* 34 */
    mp_err (*tclBN_mp_radix_size) (const mp_int *a, int radix, int *size) MP_WUR; /* 35 */
    mp_err (*tclBN_mp_read_radix) (mp_int *a, const char *str, int radix) MP_WUR; /* 36 */
    void (*tclBN_mp_rshd) (mp_int *a, int shift); /* 37 */
    mp_err (*tclBN_mp_shrink) (mp_int *a) MP_WUR; /* 38 */
    void (*tclBN_mp_set) (mp_int *a, unsigned int b); /* 39 */
    TCL_DEPRECATED_API("is private function in libtommath") mp_err (*tclBN_mp_sqr) (const mp_int *a, mp_int *b) MP_WUR; /* 40 */
    mp_err (*tclBN_mp_sqrt) (const mp_int *a, mp_int *b) MP_WUR; /* 41 */
    mp_err (*tclBN_mp_sub) (const mp_int *a, const mp_int *b, mp_int *c) MP_WUR; /* 42 */
    mp_err (*tclBN_mp_sub_d) (const mp_int *a, unsigned int b, mp_int *c) MP_WUR; /* 43 */
    TCL_DEPRECATED_API("Use mp_to_ubin") mp_err (*tclBN_mp_to_unsigned_bin) (const mp_int *a, unsigned char *b); /* 44 */
    TCL_DEPRECATED_API("Use mp_to_ubin") mp_err (*tclBN_mp_to_unsigned_bin_n) (const mp_int *a, unsigned char *b, unsigned long *outlen); /* 45 */
    TCL_DEPRECATED_API("Use mp_to_radix") mp_err (*tclBN_mp_toradix_n) (const mp_int *a, char *str, int radix, int maxlen); /* 46 */
    size_t (*tclBN_mp_ubin_size) (const mp_int *a); /* 47 */
................................................................................
#define mp_mul_d TclBN_s_mp_mul_d
#define mp_set TclBN_s_mp_set
#define mp_expt_u32 TclBN_s_mp_expt_u32
#endif /* !BUILD_tcl */

#undef TCL_STORAGE_CLASS
#define TCL_STORAGE_CLASS DLLIMPORT

#if defined(USE_TCL_STUBS)
#   define mp_sqr(a,b) mp_mul(a,a,b)
#else
#   define mp_sqr TclBN_mp_sqr
#endif

#endif /* _TCLINTDECLS */

{
   mp_err err;
   int min_len = MP_MIN(a->used, b->used),
       max_len = MP_MAX(a->used, b->used),
       digs = a->used + b->used + 1;
   mp_sign neg = (a->sign == b->sign) ? MP_ZPOS : MP_NEG;



   if (MP_HAS(S_MP_BALANCE_MUL) &&
       /* Check sizes. The smaller one needs to be larger than the Karatsuba cut-off.
        * The bigger one needs to be at least about one MP_KARATSUBA_MUL_CUTOFF bigger
        * to make some sense, but it depends on architecture, OS, position of the
        * stars... so YMMV.
        * Using it to cut the input into slices small enough for s_mp_mul_digs_fast
        * was actually slower on the author's machine, but YMMV.
        */

{
   mp_err err;
   int min_len = MP_MIN(a->used, b->used),
       max_len = MP_MAX(a->used, b->used),
       digs = a->used + b->used + 1;
   mp_sign neg = (a->sign == b->sign) ? MP_ZPOS : MP_NEG;

   if (a == b) {
       return mp_sqr(a,c);
   } else if (MP_HAS(S_MP_BALANCE_MUL) &&
       /* Check sizes. The smaller one needs to be larger than the Karatsuba cut-off.
        * The bigger one needs to be at least about one MP_KARATSUBA_MUL_CUTOFF bigger
        * to make some sense, but it depends on architecture, OS, position of the
        * stars... so YMMV.
        * Using it to cut the input into slices small enough for s_mp_mul_digs_fast
        * was actually slower on the author's machine, but YMMV.
        */

    namespace import ::tcltest::customMatch
    namespace import ::tcltest::makeFile
    namespace import ::tcltest::removeFile
    namespace import ::tcltest::temporaryDirectory
    namespace import ::tcltest::testConstraint
    namespace import ::tcltest::test

    testConstraint knownMsvcBug [expr {![info exists ::env(TRAVIS_OS_NAME)] || ![string match windows $::env(TRAVIS_OS_NAME)]}]

    proc ListGlobMatch {expected actual} {
	if {[llength $expected] != [llength $actual]} {
	    return 0
	}
	foreach e $expected a $actual {
	    if {![string match $e $a]} {
		return 0
................................................................................
# The tests for Tcl_SwitchObjCmd are in switch.test

# todo: rewrite this if monotonic clock is provided resp. command "after"
# gets microsecond accuracy (RFE [fdfbd5e10] gets merged):
proc _nrt_sleep {msec} {
    set usec [expr {$msec * 1000}]
    set stime [clock microseconds]
    while {abs([clock microseconds] - $stime) < $usec} {after 0}


}



test cmdMZ-5.1 {Tcl_TimeObjCmd: basic format of command} -body {
    time
} -returnCodes error -result {wrong # args: should be "time command ?count?"}
test cmdMZ-5.2 {Tcl_TimeObjCmd: basic format of command} -body {
    time a b c
} -returnCodes error -result {wrong # args: should be "time command ?count?"}
................................................................................
} -returnCodes error -result {expected integer but got "b"}
test cmdMZ-5.4 {Tcl_TimeObjCmd: nothing happens with negative iteration counts} {
    time bogusCmd -12456
} {0 microseconds per iteration}
test cmdMZ-5.5 {Tcl_TimeObjCmd: result format} -body {
    time {format 1}
} -match regexp -result {^\d+ microseconds per iteration}
test cmdMZ-5.6 {Tcl_TimeObjCmd: slower commands take longer} knownMsvcBug {
    expr {[lindex [time {_nrt_sleep 1}] 0] < [lindex [time {_nrt_sleep 20}] 0]}
} 1
test cmdMZ-5.7 {Tcl_TimeObjCmd: errors generate right trace} {
    list [catch {time {error foo}} msg] $msg $::errorInfo
} {1 foo {foo
    while executing
"error foo"
    invoked from within
................................................................................
} {1 {missing close-brace}}
test cmdMZ-6.5a {Tcl_TimeRateObjCmd: result format and one iteration} {
    regexp {^\d+(?:\.\d+)? \ws/# 1 # \d+(?:\.\d+)? #/sec \d+(?:\.\d+)? net-ms$} [timerate {} 0]
} 1
test cmdMZ-6.5b {Tcl_TimeRateObjCmd: result format without iterations} {
    regexp {^0 \ws/# 0 # 0 #/sec 0 net-ms$} [timerate {} 0 0]
} 1
test cmdMZ-6.6 {Tcl_TimeRateObjCmd: slower commands take longer, but it remains almost the same time of measument} knownMsvcBug {
    set m1 [timerate {_nrt_sleep 0} 20]

    set m2 [timerate {_nrt_sleep 0.2} 20]
    list \
	[expr {[lindex $m1 0] < [lindex $m2 0]}] \
	[expr {[lindex $m1 0] < 100}] \
	[expr {[lindex $m2 0] > 100}] \
	[expr {[lindex $m1 2] > 1000}] \
	[expr {[lindex $m2 2] < 1000}] \
	[expr {[lindex $m1 4] > 50000}] \
	[expr {[lindex $m2 4] < 50000}] \
	[expr {[lindex $m1 6] > 10 && [lindex $m1 6] < 100}] \
	[expr {[lindex $m2 6] > 10 && [lindex $m2 6] < 100}]
} [lrepeat 9 1]
test cmdMZ-6.7 {Tcl_TimeRateObjCmd: errors generate right trace} {
    list [catch {timerate {error foo} 1} msg] $msg $::errorInfo
} {1 foo {foo
    while executing
"error foo"
    invoked from within

    namespace import ::tcltest::customMatch
    namespace import ::tcltest::makeFile
    namespace import ::tcltest::removeFile
    namespace import ::tcltest::temporaryDirectory
    namespace import ::tcltest::testConstraint
    namespace import ::tcltest::test



    proc ListGlobMatch {expected actual} {
	if {[llength $expected] != [llength $actual]} {
	    return 0
	}
	foreach e $expected a $actual {
	    if {![string match $e $a]} {
		return 0
................................................................................
# The tests for Tcl_SwitchObjCmd are in switch.test

# todo: rewrite this if monotonic clock is provided resp. command "after"
# gets microsecond accuracy (RFE [fdfbd5e10] gets merged):
proc _nrt_sleep {msec} {
    set usec [expr {$msec * 1000}]
    set stime [clock microseconds]
    while {abs([clock microseconds] - $stime) < $usec} {
      # don't use after 0 unless it's NRT-capable, so yes - busy-wait (but it's more precise):
      # after 0
    }
}
_nrt_sleep 0; # warm up (clock, compile, etc)

test cmdMZ-5.1 {Tcl_TimeObjCmd: basic format of command} -body {
    time
} -returnCodes error -result {wrong # args: should be "time command ?count?"}
test cmdMZ-5.2 {Tcl_TimeObjCmd: basic format of command} -body {
    time a b c
} -returnCodes error -result {wrong # args: should be "time command ?count?"}
................................................................................
} -returnCodes error -result {expected integer but got "b"}
test cmdMZ-5.4 {Tcl_TimeObjCmd: nothing happens with negative iteration counts} {
    time bogusCmd -12456
} {0 microseconds per iteration}
test cmdMZ-5.5 {Tcl_TimeObjCmd: result format} -body {
    time {format 1}
} -match regexp -result {^\d+ microseconds per iteration}
test cmdMZ-5.6 {Tcl_TimeObjCmd: slower commands take longer} {
    expr {[lindex [time {_nrt_sleep 0.01}] 0] < [lindex [time {_nrt_sleep 10.0}] 0]}
} 1
test cmdMZ-5.7 {Tcl_TimeObjCmd: errors generate right trace} {
    list [catch {time {error foo}} msg] $msg $::errorInfo
} {1 foo {foo
    while executing
"error foo"
    invoked from within
................................................................................
} {1 {missing close-brace}}
test cmdMZ-6.5a {Tcl_TimeRateObjCmd: result format and one iteration} {
    regexp {^\d+(?:\.\d+)? \ws/# 1 # \d+(?:\.\d+)? #/sec \d+(?:\.\d+)? net-ms$} [timerate {} 0]
} 1
test cmdMZ-6.5b {Tcl_TimeRateObjCmd: result format without iterations} {
    regexp {^0 \ws/# 0 # 0 #/sec 0 net-ms$} [timerate {} 0 0]
} 1
test cmdMZ-6.6 {Tcl_TimeRateObjCmd: slower commands take longer, but it remains almost the same time of measument} {
    lassign [timerate {_nrt_sleep 0} 50] ovh
    set m1 [timerate -overhead $ovh {_nrt_sleep 0.01} 50]
    set m2 [timerate -overhead $ovh {_nrt_sleep 1.00} 50]
    list \
	[expr {[lindex $m1 0] < [lindex $m2 0]}] \
	[expr {[lindex $m1 0] < 100}] \
	[expr {[lindex $m2 0] > 100}] \
	[expr {[lindex $m1 2] > 500}] \
	[expr {[lindex $m2 2] < 500}] \
	[expr {[lindex $m1 4] > 10000}] \
	[expr {[lindex $m2 4] < 10000}] \
	[expr {[lindex $m1 6] > 5 && [lindex $m1 6] < 100}] \
	[expr {[lindex $m2 6] > 5 && [lindex $m2 6] < 100}]
} [lrepeat 9 1]
test cmdMZ-6.7 {Tcl_TimeRateObjCmd: errors generate right trace} {
    list [catch {timerate {error foo} 1} msg] $msg $::errorInfo
} {1 foo {foo
    while executing
"error foo"
    invoked from within