** This routines RepoFILE - that zFilename is always a file under management.
**
** On Windows, always return False.
*/
int file_islink(const char *zFilename){
  return file_perm(zFilename, RepoFILE)==PERM_LNK;
}

/*
** Check every sub-directory of zRoot along the path to zFile.
** If any sub-directory is really an ordinary file or a symbolic link,
** return an integer which is the length of the prefix of zFile which
** is the name of that object.  Return 0 if all no non-directory
** objects are found along the path.
**
** Example:  Given inputs
**
**     zRoot = /home/alice/project1
**     zFile = /home/alice/project1/main/src/js/fileA.js
**
** Look for objects in the following order:
**
**      /home/alice/project/main
**      /home/alice/project/main/src
**      /home/alice/project/main/src/js
**
** If any of those objects exist and are something other than a directory
** then return the length of the name of the first non-directory object
** seen.
*/
int file_nondir_objects_on_path(const char *zRoot, const char *zFile){
  int i = (int)strlen(zRoot);
  char *z = fossil_strdup(zFile);
  assert( fossil_strnicmp(zRoot, z, i)==0 );
  if( i && zRoot[i-1]=='/' ) i--;
  while( z[i]=='/' ){
    int j, rc;
    for(j=i+1; z[j] && z[j]!='/'; j++){}
    if( z[j]!='/' ) break;
    z[j] = 0;
    rc = file_isdir(z, SymFILE);
    if( rc!=1 ){
      if( rc==2 ){
        fossil_free(z);
        return j;
      }
      break;
    }
    z[j] = '/';
    i = j;
  }
  fossil_free(z);
  return 0;
}

/*
** The file named zFile is suppose to be an in-tree file.  Check to
** ensure that it will be safe to write to this file by verifying that
** there are no symlinks or other non-directory objects in between the
** root of the checkout and zFile.
**
** If a problem is found, print a warning message (using fossil_warning())
** and return non-zero.  If everything is ok, return zero.
*/
int file_unsafe_in_tree_path(const char *zFile){
  int n;
  if( !file_is_absolute_path(zFile) ){
    fossil_panic("%s is not an absolute pathname",zFile);
  }
  if( fossil_strnicmp(g.zLocalRoot, zFile, (int)strlen(g.zLocalRoot)) ){
    fossil_panic("%s is not a prefix of %s", g.zLocalRoot, zFile);
  }
  n = file_nondir_objects_on_path(g.zLocalRoot, zFile);
  if( n ){
    fossil_warning("cannot write to %s because non-directory object %.*s"
                   " is in the way", zFile, n, zFile);
  }
  return n;
}

/*
** Return 1 if zFilename is a directory.  Return 0 if zFilename
** does not exist.  Return 2 if zFilename exists but is something
** other than a directory.
*/
int file_isdir(const char *zFilename, int eFType){

** zFilename is a symbolic link, it is the object that zFilename points
** to that is modified.
*/
int file_setexe(const char *zFilename, int onoff){
  int rc = 0;
#if !defined(_WIN32)
  struct stat buf;
  if( fossil_stat(zFilename, &buf, RepoFILE)!=0 
   || S_ISLNK(buf.st_mode)
   || S_ISDIR(buf.st_mode)
  ){
    return 0;
  }
  if( onoff ){
    int targetMode = (buf.st_mode & 0444)>>2;
    if( (buf.st_mode & 0100)==0 ){
      chmod(zFilename, buf.st_mode | targetMode);
      rc = 1;

  if( dryRunFlag!=0 ){
    fossil_print("dry-run: would have touched %d file(s)\n",
                 changeCount);
  }else{
    fossil_print("Touched %d file(s)\n", changeCount);
  }
}

/*
** Returns non-zero if the specified file name ends with any reserved name,
** e.g.: _FOSSIL_ or .fslckout.  Specifically, it returns 1 for exact match
** or 2 for a tail match on a longer file name.
**
** For the sake of efficiency, zFilename must be a canonical name, e.g. an
** absolute path using only forward slash ('/') as a directory separator.
**
** nFilename must be the length of zFilename.  When negative, strlen() will
** be used to calculate it.
*/
int file_is_reserved_name(const char *zFilename, int nFilename){
  const char *zEnd;  /* one-after-the-end of zFilename */
  int gotSuffix = 0; /* length of suffix (-wal, -shm, -journal) */

  assert( zFilename && "API misuse" );
  if( nFilename<0 ) nFilename = (int)strlen(zFilename);
  if( nFilename<8 ) return 0; /* strlen("_FOSSIL_") */
  zEnd = zFilename + nFilename;
  if( nFilename>=12 ){ /* strlen("_FOSSIL_-(shm|wal)") */
    /* Check for (-wal, -shm, -journal) suffixes, with an eye towards
    ** runtime speed. */
    if( zEnd[-4]=='-' ){
      if( fossil_strnicmp("wal", &zEnd[-3], 3)
       && fossil_strnicmp("shm", &zEnd[-3], 3) ){
        return 0;
      }
      gotSuffix = 4;
    }else if( nFilename>=16 && zEnd[-8]=='-' ){ /*strlen(_FOSSIL_-journal) */
      if( fossil_strnicmp("journal", &zEnd[-7], 7) ) return 0;
      gotSuffix = 8;
    }
    if( gotSuffix ){
      assert( 4==gotSuffix || 8==gotSuffix );
      zEnd -= gotSuffix;
      nFilename -= gotSuffix;
      gotSuffix = 1;
    }
    assert( nFilename>=8 && "strlen(_FOSSIL_)" );
    assert( gotSuffix==0 || gotSuffix==1 );
  }
  switch( zEnd[-1] ){
    case '_':{
      if( fossil_strnicmp("_FOSSIL_", &zEnd[-8], 8) ) return 0;
      if( 8==nFilename ) return 1;
      return zEnd[-9]=='/' ? 2 : gotSuffix;
    }
    case 'T':
    case 't':{
      if( nFilename<9 || zEnd[-9]!='.'
       || fossil_strnicmp(".fslckout", &zEnd[-9], 9) ){
        return 0; 
      }
      if( 9==nFilename ) return 1;
      return zEnd[-10]=='/' ? 2 : gotSuffix;
    }
    default:{
      return 0;
    }
  }
}

/*
** COMMAND: test-is-reserved-name
**
** Usage: %fossil test-is-ckout-db FILENAMES...
**
** Passes each given name to file_is_reserved_name() and outputs one
** line per file: the result value of that function followed by the
** name.
*/
void test_is_reserved_name_cmd(void){
  int i;

  if(g.argc<3){
    usage("FILENAME_1 [...FILENAME_N]");
  }
  for( i = 2; i < g.argc; ++i ){
    const int check = file_is_reserved_name(g.argv[i], -1);
    fossil_print("%d %s\n", check, g.argv[i]);
  }
}