src/c_tcl_base_7_5_w_mods/tclfilename.c

/* $Header$ */
/* 
 * tclFileName.c --
 *
 *      This file contains routines for converting file names betwen
 *      native and network form.
 *
 * Copyright (c) 1995-1998 Sun Microsystems, Inc.
 * Copyright (c) 1998-1999 by Scriptics Corporation.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * RCS: @(#) $Id: tclfilename.c,v 1.1.1.1 2001/06/13 04:39:15 dtashley Exp $
 */

#include "tclInt.h"
#include "tclPort.h"
#include "tclRegexp.h"

/*
 * The following regular expression matches the root portion of a Windows
 * absolute or volume relative path.  It will match both UNC and drive relative
 * paths.
 */

#define WIN_ROOT_PATTERN "^(([a-zA-Z]:)|[/\\\\][/\\\\]+([^/\\\\]+)[/\\\\]+([^/\\\\]+)|([/\\\\]))([/\\\\])*"

/*
 * The following regular expression matches the root portion of a Macintosh
 * absolute path.  It will match degenerate Unix-style paths, tilde paths,
 * Unix-style paths, and Mac paths.
 */

#define MAC_ROOT_PATTERN "^((/+([.][.]?/+)*([.][.]?)?)|(~[^:/]*)(/[^:]*)?|(~[^:]*)(:.*)?|/+([.][.]?/+)*([^:/]+)(/[^:]*)?|([^:]+):.*)$"

/*
 * The following variables are used to hold precompiled regular expressions
 * for use in filename matching.
 */

typedef struct ThreadSpecificData {
    int initialized;
    Tcl_Obj *macRootPatternPtr;
} ThreadSpecificData;

static Tcl_ThreadDataKey dataKey;

/*
 * The following variable is set in the TclPlatformInit call to one
 * of: TCL_PLATFORM_UNIX, TCL_PLATFORM_MAC, or TCL_PLATFORM_WINDOWS.
 */

TclPlatformType tclPlatform = TCL_PLATFORM_UNIX;

/*
 * The "globParameters" argument of the globbing functions is an 
 * or'ed combination of the following values:
 */

#define GLOBMODE_NO_COMPLAIN      1
#define GLOBMODE_JOIN             2
#define GLOBMODE_DIR              4

/*
 * Prototypes for local procedures defined in this file:
 */

static char *           DoTildeSubst _ANSI_ARGS_((Tcl_Interp *interp,
                            CONST char *user, Tcl_DString *resultPtr));
static CONST char *     ExtractWinRoot _ANSI_ARGS_((CONST char *path,
                            Tcl_DString *resultPtr, int offset, Tcl_PathType *typePtr));
static void             FileNameCleanup _ANSI_ARGS_((ClientData clientData));
static void             FileNameInit _ANSI_ARGS_((void));
static int              SkipToChar _ANSI_ARGS_((char **stringPtr,
                            char *match));
static char *           SplitMacPath _ANSI_ARGS_((CONST char *path,
                            Tcl_DString *bufPtr));
static char *           SplitWinPath _ANSI_ARGS_((CONST char *path,
                            Tcl_DString *bufPtr));
static char *           SplitUnixPath _ANSI_ARGS_((CONST char *path,
                            Tcl_DString *bufPtr));

/*
 *----------------------------------------------------------------------
 *
 * FileNameInit --
 *
 *      This procedure initializes the patterns used by this module.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Compiles the regular expressions.
 *
 *----------------------------------------------------------------------
 */

static void
FileNameInit()
{
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
    if (!tsdPtr->initialized) {
        tsdPtr->initialized = 1;
        tsdPtr->macRootPatternPtr = Tcl_NewStringObj(MAC_ROOT_PATTERN, -1);
        Tcl_CreateThreadExitHandler(FileNameCleanup, NULL);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * FileNameCleanup --
 *
 *      This procedure is a Tcl_ExitProc used to clean up the static
 *      data structures used in this file.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Deallocates storage used by the procedures in this file.
 *
 *----------------------------------------------------------------------
 */

static void
FileNameCleanup(clientData)
    ClientData clientData;      /* Not used. */
{
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
    Tcl_DecrRefCount(tsdPtr->macRootPatternPtr);
    tsdPtr->initialized = 0;
}

/*
 *----------------------------------------------------------------------
 *
 * ExtractWinRoot --
 *
 *      Matches the root portion of a Windows path and appends it
 *      to the specified Tcl_DString.
 *      
 * Results:
 *      Returns the position in the path immediately after the root
 *      including any trailing slashes.
 *      Appends a cleaned up version of the root to the Tcl_DString
 *      at the specified offest.
 *
 * Side effects:
 *      Modifies the specified Tcl_DString.
 *
 *----------------------------------------------------------------------
 */

static CONST char *
ExtractWinRoot(path, resultPtr, offset, typePtr)
    CONST char *path;           /* Path to parse. */
    Tcl_DString *resultPtr;     /* Buffer to hold result. */
    int offset;                 /* Offset in buffer where result should be
                                 * stored. */
    Tcl_PathType *typePtr;      /* Where to store pathType result */
{
    FileNameInit();


    if (path[0] == '/' || path[0] == '\\') {
        /* Might be a UNC or Vol-Relative path */
        char *host, *share, *tail;
        int hlen, slen;
        if (path[1] != '/' && path[1] != '\\') {
            Tcl_DStringSetLength(resultPtr, offset);
            *typePtr = TCL_PATH_VOLUME_RELATIVE;
            Tcl_DStringAppend(resultPtr, "/", 1);
            return &path[1];
    }
        host = (char *)&path[2];

        /* Skip seperators */
        while (host[0] == '/' || host[0] == '\\') host++;

        for (hlen = 0; host[hlen];hlen++) {
            if (host[hlen] == '/' || host[hlen] == '\\')
                break;
        }
        if (host[hlen] == 0 || host[hlen+1] == 0) {
            *typePtr = TCL_PATH_VOLUME_RELATIVE;
            Tcl_DStringAppend(resultPtr, "/", 1);
            return &path[2];
        }
        Tcl_DStringSetLength(resultPtr, offset);
        share = &host[hlen];

        /* Skip seperators */
        while (share[0] == '/' || share[0] == '\\') share++;

        for (slen = 0; share[slen];slen++) {
            if (share[slen] == '/' || share[slen] == '\\')
                break;
        }
        Tcl_DStringAppend(resultPtr, "//", 2);
        Tcl_DStringAppend(resultPtr, host, hlen);
        Tcl_DStringAppend(resultPtr, "/", 1);
        Tcl_DStringAppend(resultPtr, share, slen);

        tail = &share[slen];

        /* Skip seperators */
        while (tail[0] == '/' || tail[0] == '\\') tail++;

        *typePtr = TCL_PATH_ABSOLUTE;
        return tail;
    } else if (path[1] == ':') {
        /* Might be a drive sep */
        Tcl_DStringSetLength(resultPtr, offset);

        if (path[2] != '/' && path[2] != '\\') {
            *typePtr = TCL_PATH_VOLUME_RELATIVE;
            Tcl_DStringAppend(resultPtr, path, 2);
            return &path[2];
    } else {
            char *tail = (char*)&path[3];

            /* Skip seperators */
            while (tail[0] == '/' || tail[0] == '\\') tail++;

            *typePtr = TCL_PATH_ABSOLUTE;
            Tcl_DStringAppend(resultPtr, path, 2);
        Tcl_DStringAppend(resultPtr, "/", 1);

    return tail;
        }
    } else {
        *typePtr = TCL_PATH_RELATIVE;
        return path;
    }
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_GetPathType --
 *
 *      Determines whether a given path is relative to the current
 *      directory, relative to the current volume, or absolute.
 *
 * Results:
 *      Returns one of TCL_PATH_ABSOLUTE, TCL_PATH_RELATIVE, or
 *      TCL_PATH_VOLUME_RELATIVE.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

Tcl_PathType
Tcl_GetPathType(path)
    char *path;
{
    ThreadSpecificData *tsdPtr;
    Tcl_PathType type = TCL_PATH_ABSOLUTE;
    Tcl_RegExp re;

    switch (tclPlatform) {
        case TCL_PLATFORM_UNIX:
            /*
             * Paths that begin with / or ~ are absolute.
             */

            if ((path[0] != '/') && (path[0] != '~')) {
                type = TCL_PATH_RELATIVE;
            }
            break;

        case TCL_PLATFORM_MAC:
            if (path[0] == ':') {
                type = TCL_PATH_RELATIVE;
            } else if (path[0] != '~') {
                tsdPtr = TCL_TSD_INIT(&dataKey);

                /*
                 * Since we have eliminated the easy cases, use the
                 * root pattern to look for the other types.
                 */

                FileNameInit();
                re = Tcl_GetRegExpFromObj(NULL, tsdPtr->macRootPatternPtr,
                        REG_ADVANCED);

                if (!Tcl_RegExpExec(NULL, re, path, path)) {
                    type = TCL_PATH_RELATIVE;
                } else {
                    char *unixRoot, *dummy;

                    Tcl_RegExpRange(re, 2, &unixRoot, &dummy);
                    if (unixRoot) {
                        type = TCL_PATH_RELATIVE;
                    }
                }
            }
            break;
        
        case TCL_PLATFORM_WINDOWS:
            if (path[0] != '~') {
                Tcl_DString ds;

                Tcl_DStringInit(&ds);
                (VOID)ExtractWinRoot(path, &ds, 0, &type);
                Tcl_DStringFree(&ds);
            }
            break;
    }
    return type;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_SplitPath --
 *
 *      Split a path into a list of path components.  The first element
 *      of the list will have the same path type as the original path.
 *
 * Results:
 *      Returns a standard Tcl result.  The interpreter result contains
 *      a list of path components.
 *      *argvPtr will be filled in with the address of an array
 *      whose elements point to the elements of path, in order.
 *      *argcPtr will get filled in with the number of valid elements
 *      in the array.  A single block of memory is dynamically allocated
 *      to hold both the argv array and a copy of the path elements.
 *      The caller must eventually free this memory by calling ckfree()
 *      on *argvPtr.  Note:  *argvPtr and *argcPtr are only modified
 *      if the procedure returns normally.
 *
 * Side effects:
 *      Allocates memory.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_SplitPath(path, argcPtr, argvPtr)
    CONST char *path;           /* Pointer to string containing a path. */
    int *argcPtr;               /* Pointer to location to fill in with
                                 * the number of elements in the path. */
    char ***argvPtr;            /* Pointer to place to store pointer to array
                                 * of pointers to path elements. */
{
    int i, size;
    char *p;
    Tcl_DString buffer;

    Tcl_DStringInit(&buffer);

    /*
     * Perform platform specific splitting.  These routines will leave the
     * result in the specified buffer.  Individual elements are terminated
     * with a null character.
     */

    p = NULL;                   /* Needed only to prevent gcc warnings. */
    switch (tclPlatform) {
        case TCL_PLATFORM_UNIX:
            p = SplitUnixPath(path, &buffer);
            break;

        case TCL_PLATFORM_WINDOWS:
            p = SplitWinPath(path, &buffer);
            break;
            
        case TCL_PLATFORM_MAC:
            p = SplitMacPath(path, &buffer);
            break;
    }

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

    size = Tcl_DStringLength(&buffer);
    *argcPtr = 0;
    for (i = 0; i < size; i++) {
        if (p[i] == '\0') {
            (*argcPtr)++;
        }
    }
    
    /*
     * Allocate a buffer large enough to hold the contents of the
     * DString plus the argv pointers and the terminating NULL pointer.
     */

    *argvPtr = (char **) ckalloc((unsigned)
            ((((*argcPtr) + 1) * sizeof(char *)) + size));

    /*
     * Position p after the last argv pointer and copy the contents of
     * the DString.
     */

    p = (char *) &(*argvPtr)[(*argcPtr) + 1];
    memcpy((VOID *) p, (VOID *) Tcl_DStringValue(&buffer), (size_t) size);

    /*
     * Now set up the argv pointers.
     */

    for (i = 0; i < *argcPtr; i++) {
        (*argvPtr)[i] = p;
        while ((*p++) != '\0') {}
    }
    (*argvPtr)[i] = NULL;

    Tcl_DStringFree(&buffer);
}

/*
 *----------------------------------------------------------------------
 *
 * SplitUnixPath --
 *
 *      This routine is used by Tcl_SplitPath to handle splitting
 *      Unix paths.
 *
 * Results:
 *      Stores a null separated array of strings in the specified
 *      Tcl_DString.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

static char *
SplitUnixPath(path, bufPtr)
    CONST char *path;           /* Pointer to string containing a path. */
    Tcl_DString *bufPtr;        /* Pointer to DString to use for the result. */
{
    int length;
    CONST char *p, *elementStart;

    /*
     * Deal with the root directory as a special case.
     */

#ifdef __QNX__
    /*
     * Check for QNX //<node id> prefix
     */
    if ((path[0] == '/') && (path[1] == '/')
            && isdigit(UCHAR(path[2]))) { /* INTL: digit */
        path += 3;
        while (isdigit(UCHAR(*path))) { /* INTL: digit */
            ++path;
        }
    }
#endif

    if (path[0] == '/') {
        Tcl_DStringAppend(bufPtr, "/", 2);
        p = path+1;
    } else {
        p = path;
    }

    /*
     * Split on slashes.  Embedded elements that start with tilde will be
     * prefixed with "./" so they are not affected by tilde substitution.
     */

    for (;;) {
        elementStart = p;
        while ((*p != '\0') && (*p != '/')) {
            p++;
        }
        length = p - elementStart;
        if (length > 0) {
            if ((elementStart[0] == '~') && (elementStart != path)) {
                Tcl_DStringAppend(bufPtr, "./", 2);
            }
            Tcl_DStringAppend(bufPtr, elementStart, length);
            Tcl_DStringAppend(bufPtr, "", 1);
        }
        if (*p++ == '\0') {
            break;
        }
    }
    return Tcl_DStringValue(bufPtr);
}

/*
 *----------------------------------------------------------------------
 *
 * SplitWinPath --
 *
 *      This routine is used by Tcl_SplitPath to handle splitting
 *      Windows paths.
 *
 * Results:
 *      Stores a null separated array of strings in the specified
 *      Tcl_DString.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

static char *
SplitWinPath(path, bufPtr)
    CONST char *path;           /* Pointer to string containing a path. */
    Tcl_DString *bufPtr;        /* Pointer to DString to use for the result. */
{
    int length;
    CONST char *p, *elementStart;
    Tcl_PathType type = TCL_PATH_ABSOLUTE;

    p = ExtractWinRoot(path, bufPtr, 0, &type);

    /*
     * Terminate the root portion, if we matched something.
     */

    if (p != path) {
        Tcl_DStringAppend(bufPtr, "", 1);
    }

    /*
     * Split on slashes.  Embedded elements that start with tilde will be
     * prefixed with "./" so they are not affected by tilde substitution.
     */

    do {
        elementStart = p;
        while ((*p != '\0') && (*p != '/') && (*p != '\\')) {
            p++;
        }
        length = p - elementStart;
        if (length > 0) {
            if ((elementStart[0] == '~') && (elementStart != path)) {
                Tcl_DStringAppend(bufPtr, "./", 2);
            }
            Tcl_DStringAppend(bufPtr, elementStart, length);
            Tcl_DStringAppend(bufPtr, "", 1);
        }
    } while (*p++ != '\0');

    return Tcl_DStringValue(bufPtr);
}

/*
 *----------------------------------------------------------------------
 *
 * SplitMacPath --
 *
 *      This routine is used by Tcl_SplitPath to handle splitting
 *      Macintosh paths.
 *
 * Results:
 *      Returns a newly allocated argv array.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

static char *
SplitMacPath(path, bufPtr)
    CONST char *path;           /* Pointer to string containing a path. */
    Tcl_DString *bufPtr;        /* Pointer to DString to use for the result. */
{
    int isMac = 0;              /* 1 if is Mac-style, 0 if Unix-style path. */
    int i, length;
    CONST char *p, *elementStart;
    Tcl_RegExp re;
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

    /*
     * Initialize the path name parser for Macintosh path names.
     */

    FileNameInit();

    /*
     * Match the root portion of a Mac path name.
     */

    i = 0;                      /* Needed only to prevent gcc warnings. */

    re = Tcl_GetRegExpFromObj(NULL, tsdPtr->macRootPatternPtr, REG_ADVANCED);

    if (Tcl_RegExpExec(NULL, re, path, path) == 1) {
        char *start, *end;

        /*
         * Treat degenerate absolute paths like / and /../.. as
         * Mac relative file names for lack of anything else to do.
         */

        Tcl_RegExpRange(re, 2, &start, &end);
        if (start) {
            Tcl_DStringAppend(bufPtr, ":", 1);
            Tcl_RegExpRange(re, 0, &start, &end);
            Tcl_DStringAppend(bufPtr, path, end - start + 1);
            return Tcl_DStringValue(bufPtr);
        }

        Tcl_RegExpRange(re, 5, &start, &end);
        if (start) {
            /*
             * Unix-style tilde prefixed paths.
             */

            isMac = 0;
            i = 5;
        } else {
            Tcl_RegExpRange(re, 7, &start, &end);
            if (start) {
                /*
                 * Mac-style tilde prefixed paths.
                 */

                isMac = 1;
                i = 7;
            } else {
                Tcl_RegExpRange(re, 10, &start, &end);
                if (start) {

                    /*
                     * Normal Unix style paths.
                     */

                    isMac = 0;
                    i = 10;
                } else {
                    Tcl_RegExpRange(re, 12, &start, &end);
                    if (start) {

                        /*
                         * Normal Mac style paths.
                         */

                        isMac = 1;
                        i = 12;
                    }
                }
            }
        }

        Tcl_RegExpRange(re, i, &start, &end);
        length = end - start;

        /*
         * Append the element and terminate it with a : and a null.  Note that
         * we are forcing the DString to contain an extra null at the end.
         */

        Tcl_DStringAppend(bufPtr, start, length);
        Tcl_DStringAppend(bufPtr, ":", 2);
        p = end;
    } else {
        isMac = (strchr(path, ':') != NULL);
        p = path;
    }
    
    if (isMac) {

        /*
         * p is pointing at the first colon in the path.  There
         * will always be one, since this is a Mac-style path.
         */

        elementStart = p++;
        while ((p = strchr(p, ':')) != NULL) {
            length = p - elementStart;
            if (length == 1) {
                while (*p == ':') {
                    Tcl_DStringAppend(bufPtr, "::", 3);
                    elementStart = p++;
                }
            } else {
                /*
                 * If this is a simple component, drop the leading colon.
                 */

                if ((elementStart[1] != '~')
                        && (strchr(elementStart+1, '/') == NULL)) {
                    elementStart++;
                    length--;
                }
                Tcl_DStringAppend(bufPtr, elementStart, length);
                Tcl_DStringAppend(bufPtr, "", 1);
                elementStart = p++;
            }
        }
        if (elementStart[1] != '\0' || elementStart == path) {
            if ((elementStart[1] != '~') && (elementStart[1] != '\0')
                        && (strchr(elementStart+1, '/') == NULL)) {
                    elementStart++;
            }
            Tcl_DStringAppend(bufPtr, elementStart, -1);
            Tcl_DStringAppend(bufPtr, "", 1);
        }
    } else {

        /*
         * Split on slashes, suppress extra /'s, and convert .. to ::. 
         */

        for (;;) {
            elementStart = p;
            while ((*p != '\0') && (*p != '/')) {
                p++;
            }
            length = p - elementStart;
            if (length > 0) {
                if ((length == 1) && (elementStart[0] == '.')) {
                    Tcl_DStringAppend(bufPtr, ":", 2);
                } else if ((length == 2) && (elementStart[0] == '.')
                        && (elementStart[1] == '.')) {
                    Tcl_DStringAppend(bufPtr, "::", 3);
                } else {
                    if (*elementStart == '~') {
                        Tcl_DStringAppend(bufPtr, ":", 1);
                    }
                    Tcl_DStringAppend(bufPtr, elementStart, length);
                    Tcl_DStringAppend(bufPtr, "", 1);
                }
            }
            if (*p++ == '\0') {
                break;
            }
        }
    }
    return Tcl_DStringValue(bufPtr);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_JoinPath --
 *
 *      Combine a list of paths in a platform specific manner.
 *
 * Results:
 *      Appends the joined path to the end of the specified
 *      returning a pointer to the resulting string.  Note that
 *      the Tcl_DString must already be initialized.
 *
 * Side effects:
 *      Modifies the Tcl_DString.
 *
 *----------------------------------------------------------------------
 */

char *
Tcl_JoinPath(argc, argv, resultPtr)
    int argc;
    char **argv;
    Tcl_DString *resultPtr;     /* Pointer to previously initialized DString. */
{
    int oldLength, length, i, needsSep;
    Tcl_DString buffer;
    char c, *dest;
    CONST char *p;
    Tcl_PathType type = TCL_PATH_ABSOLUTE;

    Tcl_DStringInit(&buffer);
    oldLength = Tcl_DStringLength(resultPtr);

    switch (tclPlatform) {
        case TCL_PLATFORM_UNIX:
            for (i = 0; i < argc; i++) {
                p = argv[i];
                /*
                 * If the path is absolute, reset the result buffer.
                 * Consume any duplicate leading slashes or a ./ in
                 * front of a tilde prefixed path that isn't at the
                 * beginning of the path.
                 */

#ifdef __QNX__
                /*
                 * Check for QNX //<node id> prefix
                 */
                if (*p && (strlen(p) > 3) && (p[0] == '/') && (p[1] == '/')
                        && isdigit(UCHAR(p[2]))) { /* INTL: digit */
                    p += 3;
                    while (isdigit(UCHAR(*p))) { /* INTL: digit */
                        ++p;
                    }
                }
#endif
                if (*p == '/') {
                    Tcl_DStringSetLength(resultPtr, oldLength);
                    Tcl_DStringAppend(resultPtr, "/", 1);
                    while (*p == '/') {
                        p++;
                    }
                } else if (*p == '~') {
                    Tcl_DStringSetLength(resultPtr, oldLength);
                } else if ((Tcl_DStringLength(resultPtr) != oldLength)
                        && (p[0] == '.') && (p[1] == '/')
                        && (p[2] == '~')) {
                    p += 2;
                }

                if (*p == '\0') {
                    continue;
                }

                /*
                 * Append a separator if needed.
                 */

                length = Tcl_DStringLength(resultPtr);
                if ((length != oldLength)
                        && (Tcl_DStringValue(resultPtr)[length-1] != '/')) {
                    Tcl_DStringAppend(resultPtr, "/", 1);
                    length++;
                }

                /*
                 * Append the element, eliminating duplicate and trailing
                 * slashes.
                 */

                Tcl_DStringSetLength(resultPtr, (int) (length + strlen(p)));
                dest = Tcl_DStringValue(resultPtr) + length;
                for (; *p != '\0'; p++) {
                    if (*p == '/') {
                        while (p[1] == '/') {
                            p++;
                        }
                        if (p[1] != '\0') {
                            *dest++ = '/';
                        }
                    } else {
                        *dest++ = *p;
                    }
                }
                length = dest - Tcl_DStringValue(resultPtr);
                Tcl_DStringSetLength(resultPtr, length);
            }
            break;

        case TCL_PLATFORM_WINDOWS:
            /*
             * Iterate over all of the components.  If a component is
             * absolute, then reset the result and start building the
             * path from the current component on.
             */

            for (i = 0; i < argc; i++) {
                p = ExtractWinRoot(argv[i], resultPtr, oldLength, &type);
                length = Tcl_DStringLength(resultPtr);
                
                /*
                 * If the pointer didn't move, then this is a relative path
                 * or a tilde prefixed path.
                 */

                if (p == argv[i]) {
                    /*
                     * Remove the ./ from tilde prefixed elements unless
                     * it is the first component.
                     */

                    if ((length != oldLength)
                            && (p[0] == '.')
                            && ((p[1] == '/') || (p[1] == '\\'))
                            && (p[2] == '~')) {
                        p += 2;
                    } else if (*p == '~') {
                        Tcl_DStringSetLength(resultPtr, oldLength);
                        length = oldLength;
                    }
                }

                if (*p != '\0') {
                    /*
                     * Check to see if we need to append a separator.
                     */

                    
                    if (length != oldLength) {
                        c = Tcl_DStringValue(resultPtr)[length-1];
                        if ((c != '/') && (c != ':')) {
                            Tcl_DStringAppend(resultPtr, "/", 1);
                        }
                    }

                    /*
                     * Append the element, eliminating duplicate and
                     * trailing slashes.
                     */

                    length = Tcl_DStringLength(resultPtr);
                    Tcl_DStringSetLength(resultPtr, (int) (length + strlen(p)));
                    dest = Tcl_DStringValue(resultPtr) + length;
                    for (; *p != '\0'; p++) {
                        if ((*p == '/') || (*p == '\\')) {
                            while ((p[1] == '/') || (p[1] == '\\')) {
                                p++;
                            }
                            if (p[1] != '\0') {
                                *dest++ = '/';
                            }
                        } else {
                            *dest++ = *p;
                        }
                    }
                    length = dest - Tcl_DStringValue(resultPtr);
                    Tcl_DStringSetLength(resultPtr, length);
                }
            }
            break;

        case TCL_PLATFORM_MAC:
            needsSep = 1;
            for (i = 0; i < argc; i++) {
                Tcl_DStringSetLength(&buffer, 0);
                p = SplitMacPath(argv[i], &buffer);
                if ((*p != ':') && (*p != '\0')
                        && (strchr(p, ':') != NULL)) {
                    Tcl_DStringSetLength(resultPtr, oldLength);
                    length = strlen(p);
                    Tcl_DStringAppend(resultPtr, p, length);
                    needsSep = 0;
                    p += length+1;
                }

                /*
                 * Now append the rest of the path elements, skipping
                 * : unless it is the first element of the path, and
                 * watching out for :: et al. so we don't end up with
                 * too many colons in the result.
                 */

                for (; *p != '\0'; p += length+1) {
                    if (p[0] == ':' && p[1] == '\0') {
                        if (Tcl_DStringLength(resultPtr) != oldLength) {
                            p++;
                        } else {
                            needsSep = 0;
                        }
                    } else {
                        c = p[1];
                        if (*p == ':') {
                            if (!needsSep) {
                                p++;
                            }
                        } else {
                            if (needsSep) {
                                Tcl_DStringAppend(resultPtr, ":", 1);
                            }
                        }
                        needsSep = (c == ':') ? 0 : 1;
                    }
                    length = strlen(p);
                    Tcl_DStringAppend(resultPtr, p, length);
                }
            }
            break;
                               
    }
    Tcl_DStringFree(&buffer);
    return Tcl_DStringValue(resultPtr);
}

/*
 *---------------------------------------------------------------------------
 *
 * Tcl_TranslateFileName --
 *
 *      Converts a file name into a form usable by the native system
 *      interfaces.  If the name starts with a tilde, it will produce a
 *      name where the tilde and following characters have been replaced
 *      by the home directory location for the named user.
 *
 * Results:
 *      The return value is a pointer to a string containing the name
 *      after tilde substitution.  If there was no tilde substitution,
 *      the return value is a pointer to a copy of the original string.
 *      If there was an error in processing the name, then an error
 *      message is left in the interp's result (if interp was not NULL)
 *      and the return value is NULL.  Space for the return value is
 *      allocated in bufferPtr; the caller must call Tcl_DStringFree()
 *      to free the space if the return value was not NULL.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

char *
Tcl_TranslateFileName(interp, name, bufferPtr)
    Tcl_Interp *interp;         /* Interpreter in which to store error
                                 * message (if necessary). */
    char *name;                 /* File name, which may begin with "~" (to
                                 * indicate current user's home directory) or
                                 * "~<user>" (to indicate any user's home
                                 * directory). */
    Tcl_DString *bufferPtr;     /* Uninitialized or free DString filled
                                 * with name after tilde substitution. */
{
    register char *p;

    /*
     * Handle tilde substitutions, if needed.
     */

    if (name[0] == '~') {
        int argc, length;
        char **argv;
        Tcl_DString temp;

        Tcl_SplitPath(name, &argc, (char ***) &argv);
        
        /*
         * Strip the trailing ':' off of a Mac path before passing the user
         * name to DoTildeSubst.
         */

        if (tclPlatform == TCL_PLATFORM_MAC) {
            length = strlen(argv[0]);
            argv[0][length-1] = '\0';
        }
        
        Tcl_DStringInit(&temp);
        argv[0] = DoTildeSubst(interp, argv[0]+1, &temp);
        if (argv[0] == NULL) {
            Tcl_DStringFree(&temp);
            ckfree((char *)argv);
            return NULL;
        }
        Tcl_DStringInit(bufferPtr);
        Tcl_JoinPath(argc, (char **) argv, bufferPtr);
        Tcl_DStringFree(&temp);
        ckfree((char*)argv);
    } else {
        Tcl_DStringInit(bufferPtr);
        Tcl_JoinPath(1, (char **) &name, bufferPtr);
    }

    /*
     * Convert forward slashes to backslashes in Windows paths because
     * some system interfaces don't accept forward slashes.
     */

    if (tclPlatform == TCL_PLATFORM_WINDOWS) {
        for (p = Tcl_DStringValue(bufferPtr); *p != '\0'; p++) {
            if (*p == '/') {
                *p = '\\';
            }
        }
    }
    return Tcl_DStringValue(bufferPtr);
}

/*
 *----------------------------------------------------------------------
 *
 * TclGetExtension --
 *
 *      This function returns a pointer to the beginning of the
 *      extension part of a file name.
 *
 * Results:
 *      Returns a pointer into name which indicates where the extension
 *      starts.  If there is no extension, returns NULL.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

char *
TclGetExtension(name)
    char *name;                 /* File name to parse. */
{
    char *p, *lastSep;

    /*
     * First find the last directory separator.
     */

    lastSep = NULL;             /* Needed only to prevent gcc warnings. */
    switch (tclPlatform) {
        case TCL_PLATFORM_UNIX:
            lastSep = strrchr(name, '/');
            break;

        case TCL_PLATFORM_MAC:
            if (strchr(name, ':') == NULL) {
                lastSep = strrchr(name, '/');
            } else {
                lastSep = strrchr(name, ':');
            }
            break;

        case TCL_PLATFORM_WINDOWS:
            lastSep = NULL;
            for (p = name; *p != '\0'; p++) {
                if (strchr("/\\:", *p) != NULL) {
                    lastSep = p;
                }
            }
            break;
    }
    p = strrchr(name, '.');
    if ((p != NULL) && (lastSep != NULL)
            && (lastSep > p)) {
        p = NULL;
    }

    /*
     * In earlier versions, we used to back up to the first period in a series
     * so that "foo..o" would be split into "foo" and "..o".  This is a
     * confusing and usually incorrect behavior, so now we split at the last
     * period in the name.
     */

    return p;
}

/*
 *----------------------------------------------------------------------
 *
 * DoTildeSubst --
 *
 *      Given a string following a tilde, this routine returns the
 *      corresponding home directory.
 *
 * Results:
 *      The result is a pointer to a static string containing the home
 *      directory in native format.  If there was an error in processing
 *      the substitution, then an error message is left in the interp's
 *      result and the return value is NULL.  On success, the results
 *      are appended to resultPtr, and the contents of resultPtr are
 *      returned.
 *
 * Side effects:
 *      Information may be left in resultPtr.
 *
 *----------------------------------------------------------------------
 */

static char *
DoTildeSubst(interp, user, resultPtr)
    Tcl_Interp *interp;         /* Interpreter in which to store error
                                 * message (if necessary). */
    CONST char *user;           /* Name of user whose home directory should be
                                 * substituted, or "" for current user. */
    Tcl_DString *resultPtr;     /* Initialized DString filled with name
                                 * after tilde substitution. */
{
    char *dir;

    if (*user == '\0') {
        Tcl_DString dirString;
        
        dir = TclGetEnv("HOME", &dirString);
        if (dir == NULL) {
            if (interp) {
                Tcl_ResetResult(interp);
                Tcl_AppendResult(interp, "couldn't find HOME environment ",
                        "variable to expand path", (char *) NULL);
            }
            return NULL;
        }
        Tcl_JoinPath(1, &dir, resultPtr);
        Tcl_DStringFree(&dirString);
    } else {
        if (TclpGetUserHome(user, resultPtr) == NULL) { 
            if (interp) {
                Tcl_ResetResult(interp);
                Tcl_AppendResult(interp, "user \"", user, "\" doesn't exist",
                        (char *) NULL);
            }
            return NULL;
        }
    }
    return resultPtr->string;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_GlobObjCmd --
 *
 *      This procedure is invoked to process the "glob" Tcl command.
 *      See the user documentation for details on what it does.
 *
 * Results:
 *      A standard Tcl result.
 *
 * Side effects:
 *      See the user documentation.
 *
 *----------------------------------------------------------------------
 */

        /* ARGSUSED */
int
Tcl_GlobObjCmd(dummy, interp, objc, objv)
    ClientData dummy;                   /* Not used. */
    Tcl_Interp *interp;                 /* Current interpreter. */
    int objc;                           /* Number of arguments. */
    Tcl_Obj *CONST objv[];              /* Argument objects. */
{
    int index, i, globFlags, pathlength, length, join, dir, result;
    char *string, *pathOrDir, *separators;
    Tcl_Obj *typePtr, *resultPtr, *look;
    Tcl_DString prefix, directory;
    static char *options[] = {
        "-directory", "-join", "-nocomplain", "-path", "-types", "--", NULL
    };
    enum options {
        GLOB_DIR, GLOB_JOIN, GLOB_NOCOMPLAIN, GLOB_PATH, GLOB_TYPE, GLOB_LAST
    };
    enum pathDirOptions {PATH_NONE = -1 , PATH_GENERAL = 0, PATH_DIR = 1};
    GlobTypeData *globTypes = NULL;

    globFlags = 0;
    join = 0;
    dir = PATH_NONE;
    pathOrDir = NULL;
    typePtr = NULL;
    resultPtr = Tcl_GetObjResult(interp);
    for (i = 1; i < objc; i++) {
        if (Tcl_GetIndexFromObj(interp, objv[i], options, "option", 0, &index)
                != TCL_OK) {
            string = Tcl_GetStringFromObj(objv[i], &length);
            if (string[0] == '-') {
                /*
                 * It looks like the command contains an option so signal
                 * an error
                 */
                return TCL_ERROR;
            } else {
                /*
                 * This clearly isn't an option; assume it's the first
                 * glob pattern.  We must clear the error
                 */
                Tcl_ResetResult(interp);
                break;
            }
        }
        switch (index) {
            case GLOB_NOCOMPLAIN:                       /* -nocomplain */
                globFlags |= GLOBMODE_NO_COMPLAIN;
                break;
            case GLOB_DIR:                              /* -dir */
                if (i == (objc-1)) {
                    Tcl_AppendToObj(resultPtr,
                            "missing argument to \"-directory\"", -1);
                    return TCL_ERROR;
                }
                if (dir != -1) {
                    Tcl_AppendToObj(resultPtr,
                            "\"-directory\" cannot be used with \"-path\"",
                            -1);
                    return TCL_ERROR;
                }
                dir = PATH_DIR;
                globFlags |= GLOBMODE_DIR;
                pathOrDir = Tcl_GetStringFromObj(objv[i+1], &pathlength);
                i++;
                break;
            case GLOB_JOIN:                             /* -join */
                join = 1;
                break;
            case GLOB_PATH:                             /* -path */
                if (i == (objc-1)) {
                    Tcl_AppendToObj(resultPtr,
                            "missing argument to \"-path\"", -1);
                    return TCL_ERROR;
                }
                if (dir != -1) {
                    Tcl_AppendToObj(resultPtr,
                            "\"-path\" cannot be used with \"-directory\"",
                            -1);
                    return TCL_ERROR;
                }
                dir = PATH_GENERAL;
                pathOrDir = Tcl_GetStringFromObj(objv[i+1], &pathlength);
                i++;
                break;
            case GLOB_TYPE:                             /* -types */
                if (i == (objc-1)) {
                    Tcl_AppendToObj(resultPtr,
                            "missing argument to \"-types\"", -1);
                    return TCL_ERROR;
                }
                typePtr = objv[i+1];
                if (Tcl_ListObjLength(interp, typePtr, &length) != TCL_OK) {
                    return TCL_ERROR;
                }
                i++;
                break;
            case GLOB_LAST:                             /* -- */
                i++;
                goto endOfForLoop;
                break;
        }
    }
    endOfForLoop:
    if (objc - i < 1) {
        Tcl_WrongNumArgs(interp, 1, objv, "?switches? name ?name ...?");
        return TCL_ERROR;
    }

    separators = NULL;          /* lint. */
    switch (tclPlatform) {
        case TCL_PLATFORM_UNIX:
            separators = "/";
            break;
        case TCL_PLATFORM_WINDOWS:
            separators = "/\\:";
            break;
        case TCL_PLATFORM_MAC:
            separators = ":";
            break;
    }
    if (dir == PATH_GENERAL) {
        char *last;

        /*
         * Find the last path separator in the path
         */
        last = pathOrDir + pathlength;
        for (; last != pathOrDir; last--) {
            if (strchr(separators, *(last-1)) != NULL) {
                break;
            }
        }
        if (last == pathOrDir + pathlength) {
            /* It's really a directory */
            dir = 1;
        } else {
            Tcl_DString pref;
            char *search, *find;
            Tcl_DStringInit(&pref);
            Tcl_DStringInit(&directory);
            if (last == pathOrDir) {
                /* The whole thing is a prefix */
                Tcl_DStringAppend(&pref, pathOrDir, -1);
                pathOrDir = NULL;
            } else {
                /* Have to split off the end */
                Tcl_DStringAppend(&pref, last, pathOrDir+pathlength-last);
                Tcl_DStringAppend(&directory, pathOrDir, last-pathOrDir-1);
                pathOrDir = Tcl_DStringValue(&directory);
            }
            /* Need to quote 'prefix' */
            Tcl_DStringInit(&prefix);
            search = Tcl_DStringValue(&pref);
            while ((find = (strpbrk(search, "\\[]*?{}"))) != NULL) {
                Tcl_DStringAppend(&prefix, search, find-search);
                Tcl_DStringAppend(&prefix, "\\", 1);
                Tcl_DStringAppend(&prefix, find, 1);
                search = find+1;
                if (*search == '\0') {
                    break;
                }
            }
            if (*search != '\0') {
                Tcl_DStringAppend(&prefix, search, -1);
            }
            Tcl_DStringFree(&pref);
        }
    }

    if (typePtr != NULL) {
        /* 
         * The rest of the possible type arguments (except 'd') are
         * platform specific.  We don't complain when they are used
         * on an incompatible platform.
         */
        Tcl_ListObjLength(interp, typePtr, &length);
        globTypes = (GlobTypeData*) ckalloc(sizeof(GlobTypeData));
        globTypes->type = 0;
        globTypes->perm = 0;
        globTypes->macType = NULL;
        globTypes->macCreator = NULL;
        while(--length >= 0) {
            int len;
            char *str;
            Tcl_ListObjIndex(interp, typePtr, length, &look);
            str = Tcl_GetStringFromObj(look, &len);
            if (strcmp("readonly", str) == 0) {
                globTypes->perm |= TCL_GLOB_PERM_RONLY;
            } else if (strcmp("hidden", str) == 0) {
                globTypes->perm |= TCL_GLOB_PERM_HIDDEN;
            } else if (len == 1) {
                switch (str[0]) {
                  case 'r':
                    globTypes->perm |= TCL_GLOB_PERM_R;
                    break;
                  case 'w':
                    globTypes->perm |= TCL_GLOB_PERM_W;
                    break;
                  case 'x':
                    globTypes->perm |= TCL_GLOB_PERM_X;
                    break;
                  case 'b':
                    globTypes->type |= TCL_GLOB_TYPE_BLOCK;
                    break;
                  case 'c':
                    globTypes->type |= TCL_GLOB_TYPE_CHAR;
                    break;
                  case 'd':
                    globTypes->type |= TCL_GLOB_TYPE_DIR;
                    break;
                  case 'p':
                    globTypes->type |= TCL_GLOB_TYPE_PIPE;
                    break;
                  case 'f':
                    globTypes->type |= TCL_GLOB_TYPE_FILE;
                    break;
                  case 'l':
                    globTypes->type |= TCL_GLOB_TYPE_LINK;
                    break;
                  case 's':
                    globTypes->type |= TCL_GLOB_TYPE_SOCK;
                    break;
                  default:
                    goto badTypesArg;
                }
            } else if (len == 4) {
                /* This is assumed to be a MacOS file type */
                if (globTypes->macType != NULL) {
                    goto badMacTypesArg;
                }
                globTypes->macType = look;
                Tcl_IncrRefCount(look);
            } else {
                Tcl_Obj* item;
                if ((Tcl_ListObjLength(NULL, look, &len) == TCL_OK) &&
                        (len == 3)) {
                    Tcl_ListObjIndex(interp, look, 0, &item);
                    if (!strcmp("macintosh", Tcl_GetString(item))) {
                        Tcl_ListObjIndex(interp, look, 1, &item);
                        if (!strcmp("type", Tcl_GetString(item))) {
                            Tcl_ListObjIndex(interp, look, 2, &item);
                            if (globTypes->macType != NULL) {
                                goto badMacTypesArg;
                            }
                            globTypes->macType = item;
                            Tcl_IncrRefCount(item);
                            continue;
                        } else if (!strcmp("creator", Tcl_GetString(item))) {
                            Tcl_ListObjIndex(interp, look, 2, &item);
                            if (globTypes->macCreator != NULL) {
                                goto badMacTypesArg;
                            }
                            globTypes->macCreator = item;
                            Tcl_IncrRefCount(item);
                            continue;
                        }
                    }
                }
                /*
                 * Error cases
                 */
                badTypesArg:
                Tcl_AppendToObj(resultPtr, "bad argument to \"-types\": ", -1);
                Tcl_AppendObjToObj(resultPtr, look);
                result = TCL_ERROR;
                goto endOfGlob;
                badMacTypesArg:
                Tcl_AppendToObj(resultPtr,
                        "only one MacOS type or creator argument to \"-types\" allowed", -1);
                result = TCL_ERROR;
                goto endOfGlob;
            }
        }
    }

    /* 
     * Now we perform the actual glob below.  This may involve joining
     * together the pattern arguments, dealing with particular file types
     * etc.  We use a 'goto' to ensure we free any memory allocated along
     * the way.
     */
    objc -= i;
    objv += i;
    /* 
     * We re-retrieve this, in case it was changed in 
     * the Tcl_ResetResult above 
     */
    resultPtr = Tcl_GetObjResult(interp);
    result = TCL_OK;
    if (join) {
        if (dir != PATH_GENERAL) {
            Tcl_DStringInit(&prefix);
        }
        for (i = 0; i < objc; i++) {
            string = Tcl_GetStringFromObj(objv[i], &length);
            Tcl_DStringAppend(&prefix, string, length);
            if (i != objc -1) {
                Tcl_DStringAppend(&prefix, separators, 1);
            }
        }
        if (TclGlob(interp, Tcl_DStringValue(&prefix), pathOrDir,
                globFlags, globTypes) != TCL_OK) {
            result = TCL_ERROR;
            goto endOfGlob;
        }
    } else {
        if (dir == PATH_GENERAL) {
            Tcl_DString str;
            for (i = 0; i < objc; i++) {
                Tcl_DStringInit(&str);
                if (dir == PATH_GENERAL) {
                    Tcl_DStringAppend(&str, Tcl_DStringValue(&prefix),
                            Tcl_DStringLength(&prefix));
                }
                string = Tcl_GetStringFromObj(objv[i], &length);
                Tcl_DStringAppend(&str, string, length);
                if (TclGlob(interp, Tcl_DStringValue(&str), pathOrDir,
                        globFlags, globTypes) != TCL_OK) {
                    result = TCL_ERROR;
                    Tcl_DStringFree(&str);
                    goto endOfGlob;
                }
            }
            Tcl_DStringFree(&str);
        } else {
            for (i = 0; i < objc; i++) {
                string = Tcl_GetString(objv[i]);
                if (TclGlob(interp, string, pathOrDir,
                        globFlags, globTypes) != TCL_OK) {
                    result = TCL_ERROR;
                    goto endOfGlob;
                }
            }
        }
    }
    if ((globFlags & GLOBMODE_NO_COMPLAIN) == 0) {
        if (Tcl_ListObjLength(interp, Tcl_GetObjResult(interp),
                &length) != TCL_OK) {
            /* This should never happen.  Maybe we should be more dramatic */
            result = TCL_ERROR;
            goto endOfGlob;
        }
        if (length == 0) {
            Tcl_AppendResult(interp, "no files matched glob pattern",
                    (join || (objc == 1)) ? " \"" : "s \"", (char *) NULL);
            if (join) {
                Tcl_AppendResult(interp, Tcl_DStringValue(&prefix),
                        (char *) NULL);
            } else {
                char *sep = "";
                for (i = 0; i < objc; i++) {
                    string = Tcl_GetString(objv[i]);
                    Tcl_AppendResult(interp, sep, string, (char *) NULL);
                    sep = " ";
                }
            }
            Tcl_AppendResult(interp, "\"", (char *) NULL);
            result = TCL_ERROR;
        }
    }
  endOfGlob:
    if (join || (dir == PATH_GENERAL)) {
        Tcl_DStringFree(&prefix);
        if (dir == PATH_GENERAL) {
            Tcl_DStringFree(&directory);
        }
    }
    if (globTypes != NULL) {
        if (globTypes->macType != NULL) {
            Tcl_DecrRefCount(globTypes->macType);
        }
        if (globTypes->macCreator != NULL) {
            Tcl_DecrRefCount(globTypes->macCreator);
        }
        ckfree((char *) globTypes);
    }
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * TclGlob --
 *
 *      This procedure prepares arguments for the TclDoGlob call.
 *      It sets the separator string based on the platform, performs
 *      tilde substitution, and calls TclDoGlob.
 *
 * Results:
 *      The return value is a standard Tcl result indicating whether
 *      an error occurred in globbing.  After a normal return the
 *      result in interp (set by TclDoGlob) holds all of the file names
 *      given by the dir and rem arguments.  After an error the
 *      result in interp will hold an error message.
 *
 * Side effects:
 *      The currentArgString is written to.
 *
 *----------------------------------------------------------------------
 */

        /* ARGSUSED */
int
TclGlob(interp, pattern, unquotedPrefix, globFlags, types)
    Tcl_Interp *interp;         /* Interpreter for returning error message
                                 * or appending list of matching file names. */
    char *pattern;              /* Glob pattern to match. Must not refer
                                 * to a static string. */
    char *unquotedPrefix;       /* Prefix to glob pattern, if non-null, which
                                 * is considered literally.  May be static. */
    int globFlags;              /* Stores or'ed combination of flags */
    GlobTypeData *types;        /* Struct containing acceptable types.
                                 * May be NULL. */
{
    char *separators;
    char *head, *tail, *start;
    char c;
    int result;
    Tcl_DString buffer;

    separators = NULL;          /* lint. */
    switch (tclPlatform) {
        case TCL_PLATFORM_UNIX:
            separators = "/";
            break;
        case TCL_PLATFORM_WINDOWS:
            separators = "/\\:";
            break;
        case TCL_PLATFORM_MAC:
            if (unquotedPrefix == NULL) {
                separators = (strchr(pattern, ':') == NULL) ? "/" : ":";
            } else {
                separators = ":";
            }
            break;
    }

    Tcl_DStringInit(&buffer);
    if (unquotedPrefix != NULL) {
        start = unquotedPrefix;
    } else {
        start = pattern;
    }

    /*
     * Perform tilde substitution, if needed.
     */

    if (start[0] == '~') {
        
        /*
         * Find the first path separator after the tilde.
         */
        for (tail = start; *tail != '\0'; tail++) {
            if (*tail == '\\') {
                if (strchr(separators, tail[1]) != NULL) {
                    break;
                }
            } else if (strchr(separators, *tail) != NULL) {
                break;
            }
        }

        /*
         * Determine the home directory for the specified user.  Note that
         * we don't allow special characters in the user name.
         */
        
        c = *tail;
        *tail = '\0';
        /*
         * I don't think we need to worry about special characters in
         * the user name anymore (Vince Darley, June 1999), since the
         * new code is designed to handle special chars.
         */
#ifndef NOT_NEEDED_ANYMORE
        head = DoTildeSubst(interp, start+1, &buffer);
#else
        
        if (strpbrk(start+1, "\\[]*?{}") == NULL) {
            head = DoTildeSubst(interp, start+1, &buffer);
        } else {
            if (!(globFlags & GLOBMODE_NO_COMPLAIN)) {
                Tcl_ResetResult(interp);
                Tcl_AppendResult(interp, "globbing characters not ",
                        "supported in user names", (char *) NULL);
            }
            head = NULL;
        }
#endif
        *tail = c;
        if (head == NULL) {
            if (globFlags & GLOBMODE_NO_COMPLAIN) {
                /*
                 * We should in fact pass down the nocomplain flag 
                 * or save the interp result or use another mechanism
                 * so the interp result is not mangled on errors in that case.
                 * but that would a bigger change than reasonable for a patch
                 * release.
                 * (see fileName.test 15.2-15.4 for expected behaviour)
                 */
                Tcl_ResetResult(interp);
                return TCL_OK;
            } else {
                return TCL_ERROR;
            }
        }
        if (head != Tcl_DStringValue(&buffer)) {
            Tcl_DStringAppend(&buffer, head, -1);
        }
        if (unquotedPrefix != NULL) {
            Tcl_DStringAppend(&buffer, tail, -1);
            tail = pattern;
        }
    } else {
        tail = pattern;
        if (unquotedPrefix != NULL) {
            Tcl_DStringAppend(&buffer,unquotedPrefix,-1);
        }
    }
    /* 
     * If the prefix is a directory, make sure it ends in a directory
     * separator.
     */
    if (unquotedPrefix != NULL) {
        if (globFlags & GLOBMODE_DIR) {
            c = Tcl_DStringValue(&buffer)[Tcl_DStringLength(&buffer)-1];
            if (strchr(separators, c) == NULL) {
                Tcl_DStringAppend(&buffer,separators,1);
            }
        }
    }

    result = TclDoGlob(interp, separators, &buffer, tail, types);
    Tcl_DStringFree(&buffer);
    if (result != TCL_OK) {
        if (globFlags & GLOBMODE_NO_COMPLAIN) {
            Tcl_ResetResult(interp);
            return TCL_OK;
        }
    }
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * SkipToChar --
 *
 *      This function traverses a glob pattern looking for the next
 *      unquoted occurance of the specified character at the same braces
 *      nesting level.
 *
 * Results:
 *      Updates stringPtr to point to the matching character, or to
 *      the end of the string if nothing matched.  The return value
 *      is 1 if a match was found at the top level, otherwise it is 0.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

static int
SkipToChar(stringPtr, match)
    char **stringPtr;                   /* Pointer string to check. */
    char *match;                        /* Pointer to character to find. */
{
    int quoted, level;
    register char *p;

    quoted = 0;
    level = 0;

    for (p = *stringPtr; *p != '\0'; p++) {
        if (quoted) {
            quoted = 0;
            continue;
        }
        if ((level == 0) && (*p == *match)) {
            *stringPtr = p;
            return 1;
        }
        if (*p == '{') {
            level++;
        } else if (*p == '}') {
            level--;
        } else if (*p == '\\') {
            quoted = 1;
        }
    }
    *stringPtr = p;
    return 0;
}

/*
 *----------------------------------------------------------------------
 *
 * TclDoGlob --
 *
 *      This recursive procedure forms the heart of the globbing
 *      code.  It performs a depth-first traversal of the tree
 *      given by the path name to be globbed.  The directory and
 *      remainder are assumed to be native format paths.  The prefix 
 *      contained in 'headPtr' is not used as a glob pattern, simply
 *      as a path specifier, so it can contain unquoted glob-sensitive
 *      characters (if the directories to which it points contain
 *      such strange characters).
 *
 * Results:
 *      The return value is a standard Tcl result indicating whether
 *      an error occurred in globbing.  After a normal return the
 *      result in interp will be set to hold all of the file names
 *      given by the dir and rem arguments.  After an error the
 *      result in interp will hold an error message.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

int
TclDoGlob(interp, separators, headPtr, tail, types)
    Tcl_Interp *interp;         /* Interpreter to use for error reporting
                                 * (e.g. unmatched brace). */
    char *separators;           /* String containing separator characters
                                 * that should be used to identify globbing
                                 * boundaries. */
    Tcl_DString *headPtr;       /* Completely expanded prefix. */
    char *tail;                 /* The unexpanded remainder of the path.
                                 * Must not be a pointer to a static string. */
    GlobTypeData *types;        /* List object containing list of acceptable types.
                                 * May be NULL. */
{
    int baseLength, quoted, count;
    int result = TCL_OK;
    char *name, *p, *openBrace, *closeBrace, *firstSpecialChar, savedChar;
    char lastChar = 0;
    
    int length = Tcl_DStringLength(headPtr);

    if (length > 0) {
        lastChar = Tcl_DStringValue(headPtr)[length-1];
    }

    /*
     * Consume any leading directory separators, leaving tail pointing
     * just past the last initial separator.
     */

    count = 0;
    name = tail;
    for (; *tail != '\0'; tail++) {
        if ((*tail == '\\') && (strchr(separators, tail[1]) != NULL)) {
            tail++;
        } else if (strchr(separators, *tail) == NULL) {
            break;
        }
        count++;
    }

    /*
     * Deal with path separators.  On the Mac, we have to watch out
     * for multiple separators, since they are special in Mac-style
     * paths.
     */

    switch (tclPlatform) {
        case TCL_PLATFORM_MAC:
            if (*separators == '/') {
                if (((length == 0) && (count == 0))
                        || ((length > 0) && (lastChar != ':'))) {
                    Tcl_DStringAppend(headPtr, ":", 1);
                }
            } else {
                if (count == 0) {
                    if ((length > 0) && (lastChar != ':')) {
                        Tcl_DStringAppend(headPtr, ":", 1);
                    }
                } else {
                    if (lastChar == ':') {
                        count--;
                    }
                    while (count-- > 0) {
                        Tcl_DStringAppend(headPtr, ":", 1);
                    }
                }
            }
            break;
        case TCL_PLATFORM_WINDOWS:
            /*
             * If this is a drive relative path, add the colon and the
             * trailing slash if needed.  Otherwise add the slash if
             * this is the first absolute element, or a later relative
             * element.  Add an extra slash if this is a UNC path.
             */

            if (*name == ':') {
                Tcl_DStringAppend(headPtr, ":", 1);
                if (count > 1) {
                    Tcl_DStringAppend(headPtr, "/", 1);
                }
            } else if ((*tail != '\0')
                    && (((length > 0)
                            && (strchr(separators, lastChar) == NULL))
                            || ((length == 0) && (count > 0)))) {
                Tcl_DStringAppend(headPtr, "/", 1);
                if ((length == 0) && (count > 1)) {
                    Tcl_DStringAppend(headPtr, "/", 1);
                }
            }
            
            break;
        case TCL_PLATFORM_UNIX:
            /*
             * Add a separator if this is the first absolute element, or
             * a later relative element.
             */

            if ((*tail != '\0')
                    && (((length > 0)
                            && (strchr(separators, lastChar) == NULL))
                            || ((length == 0) && (count > 0)))) {
                Tcl_DStringAppend(headPtr, "/", 1);
            }
            break;
    }

    /*
     * Look for the first matching pair of braces or the first
     * directory separator that is not inside a pair of braces.
     */

    openBrace = closeBrace = NULL;
    quoted = 0;
    for (p = tail; *p != '\0'; p++) {
        if (quoted) {
            quoted = 0;
        } else if (*p == '\\') {
            quoted = 1;
            if (strchr(separators, p[1]) != NULL) {
                break;                  /* Quoted directory separator. */
            }
        } else if (strchr(separators, *p) != NULL) {
            break;                      /* Unquoted directory separator. */
        } else if (*p == '{') {
            openBrace = p;
            p++;
            if (SkipToChar(&p, "}")) {
                closeBrace = p;         /* Balanced braces. */
                break;
            }
            Tcl_SetResult(interp, "unmatched open-brace in file name",
                    TCL_STATIC);
            return TCL_ERROR;
        } else if (*p == '}') {
            Tcl_SetResult(interp, "unmatched close-brace in file name",
                    TCL_STATIC);
            return TCL_ERROR;
        }
    }

    /*
     * Substitute the alternate patterns from the braces and recurse.
     */

    if (openBrace != NULL) {
        char *element;
        Tcl_DString newName;
        Tcl_DStringInit(&newName);

        /*
         * For each element within in the outermost pair of braces,
         * append the element and the remainder to the fixed portion
         * before the first brace and recursively call TclDoGlob.
         */

        Tcl_DStringAppend(&newName, tail, openBrace-tail);
        baseLength = Tcl_DStringLength(&newName);
        length = Tcl_DStringLength(headPtr);
        *closeBrace = '\0';
        for (p = openBrace; p != closeBrace; ) {
            p++;
            element = p;
            SkipToChar(&p, ",");
            Tcl_DStringSetLength(headPtr, length);
            Tcl_DStringSetLength(&newName, baseLength);
            Tcl_DStringAppend(&newName, element, p-element);
            Tcl_DStringAppend(&newName, closeBrace+1, -1);
            result = TclDoGlob(interp, separators,
                    headPtr, Tcl_DStringValue(&newName), types);
            if (result != TCL_OK) {
                break;
            }
        }
        *closeBrace = '}';
        Tcl_DStringFree(&newName);
        return result;
    }

    /*
     * At this point, there are no more brace substitutions to perform on
     * this path component.  The variable p is pointing at a quoted or
     * unquoted directory separator or the end of the string.  So we need
     * to check for special globbing characters in the current pattern.
     * We avoid modifying tail if p is pointing at the end of the string.
     */

    if (*p != '\0') {

        /*
         * Note that we are modifying the string in place.  This won't work
         * if the string is a static.
         */

         savedChar = *p;
         *p = '\0';
         firstSpecialChar = strpbrk(tail, "*[]?\\");
         *p = savedChar;
    } else {
        firstSpecialChar = strpbrk(tail, "*[]?\\");
    }

    if (firstSpecialChar != NULL) {
        /*
         * Look for matching files in the current directory.  The
         * implementation of this function is platform specific, but may
         * recursively call TclDoGlob.  For each file that matches, it will
         * add the match onto the interp's result, or call TclDoGlob if there
         * are more characters to be processed.
         */

        return TclpMatchFilesTypes(interp, separators, headPtr, tail, p, types);
    }
    Tcl_DStringAppend(headPtr, tail, p-tail);
    if (*p != '\0') {
        return TclDoGlob(interp, separators, headPtr, p, types);
    }

    /*
     * There are no more wildcards in the pattern and no more unprocessed
     * characters in the tail, so now we can construct the path and verify
     * the existence of the file.
     */

    switch (tclPlatform) {
        case TCL_PLATFORM_MAC: {
            if (strchr(Tcl_DStringValue(headPtr), ':') == NULL) {
                Tcl_DStringAppend(headPtr, ":", 1);
            }
            name = Tcl_DStringValue(headPtr);
            if (TclpAccess(name, F_OK) == 0) {
                if ((name[1] != '\0') && (strchr(name+1, ':') == NULL)) {
                    Tcl_ListObjAppendElement(interp, Tcl_GetObjResult(interp), 
                                             Tcl_NewStringObj(name + 1,-1));
                } else {
                    Tcl_ListObjAppendElement(interp, Tcl_GetObjResult(interp), 
                                             Tcl_NewStringObj(name,-1));
                }
            }
            break;
        }
        case TCL_PLATFORM_WINDOWS: {
            int exists;
            
            /*
             * We need to convert slashes to backslashes before checking
             * for the existence of the file.  Once we are done, we need
             * to convert the slashes back.
             */

            if (Tcl_DStringLength(headPtr) == 0) {
                if (((*name == '\\') && (name[1] == '/' || name[1] == '\\'))
                        || (*name == '/')) {
                    Tcl_DStringAppend(headPtr, "\\", 1);
                } else {
                    Tcl_DStringAppend(headPtr, ".", 1);
                }
            } else {
                for (p = Tcl_DStringValue(headPtr); *p != '\0'; p++) {
                    if (*p == '/') {
                        *p = '\\';
                    }
                }
            }
            name = Tcl_DStringValue(headPtr);
            exists = (TclpAccess(name, F_OK) == 0);

            for (p = name; *p != '\0'; p++) {
                if (*p == '\\') {
                    *p = '/';
                }
            }
            if (exists) {
                Tcl_ListObjAppendElement(interp, Tcl_GetObjResult(interp), 
                                         Tcl_NewStringObj(name,-1));
            }
            break;
        }
        case TCL_PLATFORM_UNIX: {
            if (Tcl_DStringLength(headPtr) == 0) {
                if ((*name == '\\' && name[1] == '/') || (*name == '/')) {
                    Tcl_DStringAppend(headPtr, "/", 1);
                } else {
                    Tcl_DStringAppend(headPtr, ".", 1);
                }
            }
            name = Tcl_DStringValue(headPtr);
            if (TclpAccess(name, F_OK) == 0) {
                Tcl_ListObjAppendElement(interp, Tcl_GetObjResult(interp), 
                                         Tcl_NewStringObj(name,-1));
            }
            break;
        }
    }

    return TCL_OK;
}

/* End of tclfilename.c */