* 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.
 *
 * RCS: @(#) $Id: tclIOUtil.c,v 1.145 2007/04/25 19:09:03 kennykb Exp $
 * RCS: @(#) $Id: tclIOUtil.c,v 1.146 2007/08/15 17:43:58 dkf Exp $
 */

#include "tclInt.h"
#ifdef __WIN32__
#   include "tclWinInt.h"
#endif
#include "tclFileSystem.h"

	case 'r':
	    mode = O_RDONLY;
	    break;
	case 'w':
	    mode = O_WRONLY|O_CREAT|O_TRUNC;
	    break;
	case 'a':
	    /* [Bug 680143].
	     * Added O_APPEND for proper automatic
	     * seek-to-end-on-write by the OS.
	    /*
	     * 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:
	error:
	    goto error;
	    *seekFlagPtr = 0;
	    *binaryPtr = 0;
	    if (interp != NULL) {
		Tcl_AppendResult(interp, "illegal access mode \"", modeString,
			"\"", NULL);
	    }
	    return -1;
	}
	i=1;
	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);
		mode &= ~(O_RDONLY|O_WRONLY|O_APPEND);
		mode |= O_RDWR;
		break;
	    case 'b':
		*binaryPtr = 1;
		break;
	    default:
		goto error;
	    }
	}
	if (modeString[i] != 0) {
	    goto error;
	}
	return mode;

    error:
	*seekFlagPtr = 0;
	*binaryPtr = 0;
	if (interp != NULL) {
	    Tcl_AppendResult(interp, "illegal access mode \"", modeString,
		    "\"", NULL);
	}
	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