source: downloads/tcl8.5.2/generic/tclFileName.c @ 25

/*
 * 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 1.86 2007/12/13 15:23:17 dgp Exp $
 */

#include "tclInt.h"
#include "tclRegexp.h"
#include "tclFileSystem.h" /* For TclGetPathType() */

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

TclPlatformType tclPlatform = TCL_PLATFORM_UNIX;

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

static const char *     DoTildeSubst(Tcl_Interp *interp,
                            const char *user, Tcl_DString *resultPtr);
static const char *     ExtractWinRoot(const char *path,
                            Tcl_DString *resultPtr, int offset,
                            Tcl_PathType *typePtr);
static int              SkipToChar(char **stringPtr, int match);
static Tcl_Obj*         SplitWinPath(const char *path);
static Tcl_Obj*         SplitUnixPath(const char *path);
static int              DoGlob(Tcl_Interp *interp, Tcl_Obj *resultPtr,
                            const char *separators, Tcl_Obj *pathPtr, int flags,
                            char *pattern, Tcl_GlobTypeData *types);

/*
 *----------------------------------------------------------------------
 *
 * SetResultLength --
 *
 *      Resets the result DString for ExtractWinRoot to accommodate
 *      any NT extended path prefixes.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      May modify the Tcl_DString.
 *----------------------------------------------------------------------
 */

static void
SetResultLength(
    Tcl_DString *resultPtr,
    int offset,
    int extended)
{
    Tcl_DStringSetLength(resultPtr, offset);
    if (extended == 2) {
        Tcl_DStringAppend(resultPtr, "//?/UNC/", 8);
    } else if (extended == 1) {
        Tcl_DStringAppend(resultPtr, "//?/", 4);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * 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(
    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 */
{
    int extended = 0;

    if (   (path[0] == '/' || path[0] == '\\')
        && (path[1] == '/' || path[1] == '\\')
        && (path[2] == '?')
        && (path[3] == '/' || path[3] == '\\')) {
        extended = 1;
        path = path + 4;
        if (path[0] == 'U' && path[1] == 'N' && path[2] == 'C'
            && (path[3] == '/' || path[3] == '\\')) {
            extended = 2;
            path = path + 4;
        }
    }

    if (path[0] == '/' || path[0] == '\\') {
        /*
         * Might be a UNC or Vol-Relative path.
         */

        const char *host, *share, *tail;
        int hlen, slen;

        if (path[1] != '/' && path[1] != '\\') {
            SetResultLength(resultPtr, offset, extended);
            *typePtr = TCL_PATH_VOLUME_RELATIVE;
            Tcl_DStringAppend(resultPtr, "/", 1);
            return &path[1];
        }
        host = &path[2];

        /*
         * Skip separators.
         */

        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) {
            /*
             * The path given is simply of the form '/foo', '//foo',
             * '/////foo' or the same with backslashes. If there is exactly
             * one leading '/' the path is volume relative (see filename man
             * page). If there are more than one, we are simply assuming they
             * are superfluous and we trim them away. (An alternative
             * interpretation would be that it is a host name, but we have
             * been documented that that is not the case).
             */

            *typePtr = TCL_PATH_VOLUME_RELATIVE;
            Tcl_DStringAppend(resultPtr, "/", 1);
            return &path[2];
        }
        SetResultLength(resultPtr, offset, extended);
        share = &host[hlen];

        /*
         * Skip separators.
         */

        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 separators.
         */

        while (tail[0] == '/' || tail[0] == '\\') {
            tail++;
        }

        *typePtr = TCL_PATH_ABSOLUTE;
        return tail;
    } else if (*path && path[1] == ':') {
        /*
         * Might be a drive separator.
         */

        SetResultLength(resultPtr, offset, extended);

        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 separators.
             */

            while (*tail && (tail[0] == '/' || tail[0] == '\\')) {
                tail++;
            }

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

            return tail;
        }
    } else {
        int abs = 0;

        /*
         * Check for Windows devices.
         */

        if ((path[0] == 'c' || path[0] == 'C')
                && (path[1] == 'o' || path[1] == 'O')) {
            if ((path[2] == 'm' || path[2] == 'M')
                    && path[3] >= '1' && path[3] <= '4') {
                /*
                 * May have match for 'com[1-4]:?', which is a serial port.
                 */

                if (path[4] == '\0') {
                    abs = 4;
                } else if (path [4] == ':' && path[5] == '\0') {
                    abs = 5;
                }

            } else if ((path[2] == 'n' || path[2] == 'N') && path[3] == '\0') {
                /*
                 * Have match for 'con'.
                 */

                abs = 3;
            }

        } else if ((path[0] == 'l' || path[0] == 'L')
                && (path[1] == 'p' || path[1] == 'P')
                && (path[2] == 't' || path[2] == 'T')) {
            if (path[3] >= '1' && path[3] <= '3') {
                /*
                 * May have match for 'lpt[1-3]:?'
                 */

                if (path[4] == '\0') {
                    abs = 4;
                } else if (path [4] == ':' && path[5] == '\0') {
                    abs = 5;
                }
            }

        } else if ((path[0] == 'p' || path[0] == 'P')
                && (path[1] == 'r' || path[1] == 'R')
                && (path[2] == 'n' || path[2] == 'N')
                && path[3] == '\0') {
            /*
             * Have match for 'prn'.
             */
            abs = 3;

        } else if ((path[0] == 'n' || path[0] == 'N')
                && (path[1] == 'u' || path[1] == 'U')
                && (path[2] == 'l' || path[2] == 'L')
                && path[3] == '\0') {
            /*
             * Have match for 'nul'.
             */

            abs = 3;

        } else if ((path[0] == 'a' || path[0] == 'A')
                && (path[1] == 'u' || path[1] == 'U')
                && (path[2] == 'x' || path[2] == 'X')
                && path[3] == '\0') {
            /*
             * Have match for 'aux'.
             */

            abs = 3;
        }

        if (abs != 0) {
            *typePtr = TCL_PATH_ABSOLUTE;
            SetResultLength(resultPtr, offset, extended);
            Tcl_DStringAppend(resultPtr, path, abs);
            return path + abs;
        }
    }

    /*
     * Anything else is treated as relative.
     */

    *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.
 *
 *      The objectified Tcl_FSGetPathType should be used in preference to this
 *      function (as you can see below, this is just a wrapper around that
 *      other function).
 *
 * Results:
 *      Returns one of TCL_PATH_ABSOLUTE, TCL_PATH_RELATIVE, or
 *      TCL_PATH_VOLUME_RELATIVE.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

Tcl_PathType
Tcl_GetPathType(
    const char *path)
{
    Tcl_PathType type;
    Tcl_Obj *tempObj = Tcl_NewStringObj(path,-1);

    Tcl_IncrRefCount(tempObj);
    type = Tcl_FSGetPathType(tempObj);
    Tcl_DecrRefCount(tempObj);
    return type;
}

/*
 *----------------------------------------------------------------------
 *
 * TclpGetNativePathType --
 *
 *      Determines whether a given path is relative to the current directory,
 *      relative to the current volume, or absolute, but ONLY FOR THE NATIVE
 *      FILESYSTEM. This function is called from tclIOUtil.c (but needs to be
 *      here due to its dependence on static variables/functions in this
 *      file). The exported function Tcl_FSGetPathType should be used by
 *      extensions.
 *
 *      Note that '~' paths are always considered TCL_PATH_ABSOLUTE, even
 *      though expanding the '~' could lead to any possible path type. This
 *      function should therefore be considered a low-level, string
 *      manipulation function only -- it doesn't actually do any expansion in
 *      making its determination.
 *
 * Results:
 *      Returns one of TCL_PATH_ABSOLUTE, TCL_PATH_RELATIVE, or
 *      TCL_PATH_VOLUME_RELATIVE.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

Tcl_PathType
TclpGetNativePathType(
    Tcl_Obj *pathPtr,           /* Native path of interest */
    int *driveNameLengthPtr,    /* Returns length of drive, if non-NULL and
                                 * path was absolute */
    Tcl_Obj **driveNameRef)
{
    Tcl_PathType type = TCL_PATH_ABSOLUTE;
    int pathLen;
    char *path = Tcl_GetStringFromObj(pathPtr, &pathLen);

    if (path[0] == '~') {
        /*
         * This case is common to all platforms. Paths that begin with ~ are
         * absolute.
         */

        if (driveNameLengthPtr != NULL) {
            char *end = path + 1;
            while ((*end != '\0') && (*end != '/')) {
                end++;
            }
            *driveNameLengthPtr = end - path;
        }
    } else {
        switch (tclPlatform) {
        case TCL_PLATFORM_UNIX: {
            char *origPath = path;

            /*
             * Paths that begin with / are absolute.
             */

#ifdef __QNX__
            /*
             * Check for QNX //<node id> prefix
             */
            if (*path && (pathLen > 3) && (path[0] == '/')
                    && (path[1] == '/') && isdigit(UCHAR(path[2]))) {
                path += 3;
                while (isdigit(UCHAR(*path))) {
                    ++path;
                }
            }
#endif
            if (path[0] == '/') {
                if (driveNameLengthPtr != NULL) {
                    /*
                     * We need this addition in case the QNX code was used.
                     */

                    *driveNameLengthPtr = (1 + path - origPath);
                }
            } else {
                type = TCL_PATH_RELATIVE;
            }
            break;
        }
        case TCL_PLATFORM_WINDOWS: {
            Tcl_DString ds;
            const char *rootEnd;

            Tcl_DStringInit(&ds);
            rootEnd = ExtractWinRoot(path, &ds, 0, &type);
            if ((rootEnd != path) && (driveNameLengthPtr != NULL)) {
                *driveNameLengthPtr = rootEnd - path;
                if (driveNameRef != NULL) {
                    *driveNameRef = Tcl_NewStringObj(Tcl_DStringValue(&ds),
                            Tcl_DStringLength(&ds));
                    Tcl_IncrRefCount(*driveNameRef);
                }
            }
            Tcl_DStringFree(&ds);
            break;
        }
        }
    }
    return type;
}

/*
 *---------------------------------------------------------------------------
 *
 * TclpNativeSplitPath --
 *
 *      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.
 *
 *      Note this function currently calls the older Split(Plat)Path
 *      functions, which require more memory allocation than is desirable.
 *
 * 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 *
TclpNativeSplitPath(
    Tcl_Obj *pathPtr,           /* Path to split. */
    int *lenPtr)                /* int to store number of path elements. */
{
    Tcl_Obj *resultPtr = NULL;  /* Needed only to prevent gcc warnings. */

    /*
     * Perform platform specific splitting.
     */

    switch (tclPlatform) {
    case TCL_PLATFORM_UNIX:
        resultPtr = SplitUnixPath(Tcl_GetString(pathPtr));
        break;

    case TCL_PLATFORM_WINDOWS:
        resultPtr = SplitWinPath(Tcl_GetString(pathPtr));
        break;
    }

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

    if (lenPtr != NULL) {
        Tcl_ListObjLength(NULL, resultPtr, lenPtr);
    }
    return resultPtr;
}

/*
 *----------------------------------------------------------------------
 *
 * 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(
    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. */
    const char ***argvPtr)      /* Pointer to place to store pointer to array
                                 * of pointers to path elements. */
{
    Tcl_Obj *resultPtr = NULL;  /* Needed only to prevent gcc warnings. */
    Tcl_Obj *tmpPtr, *eltPtr;
    int i, size, len;
    char *p, *str;

    /*
     * Perform the splitting, using objectified, vfs-aware code.
     */

    tmpPtr = Tcl_NewStringObj(path, -1);
    Tcl_IncrRefCount(tmpPtr);
    resultPtr = Tcl_FSSplitPath(tmpPtr, argcPtr);
    Tcl_IncrRefCount(resultPtr);
    Tcl_DecrRefCount(tmpPtr);

    /*
     * Calculate space required for the result.
     */

    size = 1;
    for (i = 0; i < *argcPtr; i++) {
        Tcl_ListObjIndex(NULL, resultPtr, i, &eltPtr);
        Tcl_GetStringFromObj(eltPtr, &len);
        size += len + 1;
    }

    /*
     * Allocate a buffer large enough to hold the contents of all of the list
     * plus the argv pointers and the terminating NULL pointer.
     */

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

    /*
     * Position p after the last argv pointer and copy the contents of the
     * list in, piece by piece.
     */

    p = (char *) &(*argvPtr)[(*argcPtr) + 1];
    for (i = 0; i < *argcPtr; i++) {
        Tcl_ListObjIndex(NULL, resultPtr, i, &eltPtr);
        str = Tcl_GetStringFromObj(eltPtr, &len);
        memcpy(p, str, (size_t) len+1);
        p += len+1;
    }

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

    p = (char *) &(*argvPtr)[(*argcPtr) + 1];

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

    /*
     * Free the result ptr given to us by Tcl_FSSplitPath
     */

    Tcl_DecrRefCount(resultPtr);
}

/*
 *----------------------------------------------------------------------
 *
 * SplitUnixPath --
 *
 *      This routine is used by Tcl_(FS)SplitPath to handle splitting Unix
 *      paths.
 *
 * Results:
 *      Returns a newly allocated Tcl list object.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

static Tcl_Obj *
SplitUnixPath(
    const char *path)           /* Pointer to string containing a path. */
{
    int length;
    const char *p, *elementStart;
    Tcl_Obj *result = Tcl_NewObj();

    /*
     * 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_ListObjAppendElement(NULL, result, Tcl_NewStringObj("/",1));
        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) {
            Tcl_Obj *nextElt;
            if ((elementStart[0] == '~') && (elementStart != path)) {
                TclNewLiteralStringObj(nextElt, "./");
                Tcl_AppendToObj(nextElt, elementStart, length);
            } else {
                nextElt = Tcl_NewStringObj(elementStart, length);
            }
            Tcl_ListObjAppendElement(NULL, result, nextElt);
        }
        if (*p++ == '\0') {
            break;
        }
    }
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * SplitWinPath --
 *
 *      This routine is used by Tcl_(FS)SplitPath to handle splitting Windows
 *      paths.
 *
 * Results:
 *      Returns a newly allocated Tcl list object.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

static Tcl_Obj *
SplitWinPath(
    const char *path)           /* Pointer to string containing a path. */
{
    int length;
    const char *p, *elementStart;
    Tcl_PathType type = TCL_PATH_ABSOLUTE;
    Tcl_DString buf;
    Tcl_Obj *result = Tcl_NewObj();
    Tcl_DStringInit(&buf);

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

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

    if (p != path) {
        Tcl_ListObjAppendElement(NULL, result, Tcl_NewStringObj(
                Tcl_DStringValue(&buf), Tcl_DStringLength(&buf)));
    }
    Tcl_DStringFree(&buf);

    /*
     * Split on slashes. Embedded elements that start with tilde or a drive
     * letter 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) {
            Tcl_Obj *nextElt;
            if ((elementStart != path) && ((elementStart[0] == '~')
                    || (isalpha(UCHAR(elementStart[0]))
                        && elementStart[1] == ':'))) {
                TclNewLiteralStringObj(nextElt, "./");
                Tcl_AppendToObj(nextElt, elementStart, length);
            } else {
                nextElt = Tcl_NewStringObj(elementStart, length);
            }
            Tcl_ListObjAppendElement(NULL, result, nextElt);
        }
    } while (*p++ != '\0');

    return result;
}

/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSJoinToPath --
 *
 *      This function takes the given object, which should usually be a valid
 *      path or NULL, and joins onto it the array of paths segments given.
 *
 *      The objects in the array given will temporarily have their refCount
 *      increased by one, and then decreased by one when this function exits
 *      (which means if they had zero refCount when we were called, they will
 *      be freed).
 *
 * Results:
 *      Returns object owned by the caller (which should increment its
 *      refCount) - typically an object with refCount of zero.
 *
 * Side effects:
 *      None.
 *
 *---------------------------------------------------------------------------
 */

Tcl_Obj *
Tcl_FSJoinToPath(
    Tcl_Obj *pathPtr,           /* Valid path or NULL. */
    int objc,                   /* Number of array elements to join */
    Tcl_Obj *const objv[])      /* Path elements to join. */
{
    int i;
    Tcl_Obj *lobj, *ret;

    if (pathPtr == NULL) {
        lobj = Tcl_NewListObj(0, NULL);
    } else {
        lobj = Tcl_NewListObj(1, &pathPtr);
    }

    for (i = 0; i<objc;i++) {
        Tcl_ListObjAppendElement(NULL, lobj, objv[i]);
    }
    ret = Tcl_FSJoinPath(lobj, -1);

    /*
     * It is possible that 'ret' is just a member of the list and is therefore
     * going to be freed here. Therefore we must adjust the refCount manually.
     * (It would be better if we changed the documentation of this function
     * and Tcl_FSJoinPath so that the returned object already has a refCount
     * for the caller, hence avoiding these subtleties (and code ugliness)).
     */

    Tcl_IncrRefCount(ret);
    Tcl_DecrRefCount(lobj);
    ret->refCount--;
    return ret;
}

/*
 *---------------------------------------------------------------------------
 *
 * TclpNativeJoinPath --
 *
 *      'prefix' is absolute, 'joining' is relative to prefix.
 *
 * Results:
 *      modifies prefix
 *
 * Side effects:
 *      None.
 *
 *---------------------------------------------------------------------------
 */

void
TclpNativeJoinPath(
    Tcl_Obj *prefix,
    char *joining)
{
    int length, needsSep;
    char *dest, *p, *start;

    start = Tcl_GetStringFromObj(prefix, &length);

    /*
     * Remove the ./ from tilde prefixed elements, and drive-letter prefixed
     * elements on Windows, unless it is the first component.
     */

    p = joining;

    if (length != 0) {
        if ((p[0] == '.') && (p[1] == '/') && ((p[2] == '~')
                || (tclPlatform==TCL_PLATFORM_WINDOWS && isalpha(UCHAR(p[2]))
                && (p[3] == ':')))) {
            p += 2;
        }
    }
    if (*p == '\0') {
        return;
    }

    switch (tclPlatform) {
    case TCL_PLATFORM_UNIX:
        /*
         * Append a separator if needed.
         */

        if (length > 0 && (start[length-1] != '/')) {
            Tcl_AppendToObj(prefix, "/", 1);
            length++;
        }
        needsSep = 0;

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

        Tcl_SetObjLength(prefix, length + (int) strlen(p));

        dest = Tcl_GetString(prefix) + length;
        for (; *p != '\0'; p++) {
            if (*p == '/') {
                while (p[1] == '/') {
                    p++;
                }
                if (p[1] != '\0' && needsSep) {
                    *dest++ = '/';
                }
            } else {
                *dest++ = *p;
                needsSep = 1;
            }
        }
        length = dest - Tcl_GetString(prefix);
        Tcl_SetObjLength(prefix, length);
        break;

    case TCL_PLATFORM_WINDOWS:
        /*
         * Check to see if we need to append a separator.
         */

        if ((length > 0) &&
                (start[length-1] != '/') && (start[length-1] != ':')) {
            Tcl_AppendToObj(prefix, "/", 1);
            length++;
        }
        needsSep = 0;

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

        Tcl_SetObjLength(prefix, length + (int) strlen(p));
        dest = Tcl_GetString(prefix) + length;
        for (; *p != '\0'; p++) {
            if ((*p == '/') || (*p == '\\')) {
                while ((p[1] == '/') || (p[1] == '\\')) {
                    p++;
                }
                if ((p[1] != '\0') && needsSep) {
                    *dest++ = '/';
                }
            } else {
                *dest++ = *p;
                needsSep = 1;
            }
        }
        length = dest - Tcl_GetString(prefix);
        Tcl_SetObjLength(prefix, length);
        break;
    }
    return;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_JoinPath --
 *
 *      Combine a list of paths in a platform specific manner. The function
 *      'Tcl_FSJoinPath' should be used in preference where possible.
 *
 * Results:
 *      Appends the joined path to the end of the specified Tcl_DString
 *      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(
    int argc,
    const char *const *argv,
    Tcl_DString *resultPtr)     /* Pointer to previously initialized DString */
{
    int i, len;
    Tcl_Obj *listObj = Tcl_NewObj();
    Tcl_Obj *resultObj;
    char *resultStr;

    /*
     * Build the list of paths.
     */

    for (i = 0; i < argc; i++) {
        Tcl_ListObjAppendElement(NULL, listObj,
                Tcl_NewStringObj(argv[i], -1));
    }

    /*
     * Ask the objectified code to join the paths.
     */

    Tcl_IncrRefCount(listObj);
    resultObj = Tcl_FSJoinPath(listObj, argc);
    Tcl_IncrRefCount(resultObj);
    Tcl_DecrRefCount(listObj);

    /*
     * Store the result.
     */

    resultStr = Tcl_GetStringFromObj(resultObj, &len);
    Tcl_DStringAppend(resultPtr, resultStr, len);
    Tcl_DecrRefCount(resultObj);

    /*
     * Return a pointer to the result.
     */

    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(
    Tcl_Interp *interp,         /* Interpreter in which to store error message
                                 * (if necessary). */
    const 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. */
{
    Tcl_Obj *path = Tcl_NewStringObj(name, -1);
    Tcl_Obj *transPtr;

    Tcl_IncrRefCount(path);
    transPtr = Tcl_FSGetTranslatedPath(interp, path);
    if (transPtr == NULL) {
        Tcl_DecrRefCount(path);
        return NULL;
    }

    Tcl_DStringInit(bufferPtr);
    Tcl_DStringAppend(bufferPtr, Tcl_GetString(transPtr), -1);
    Tcl_DecrRefCount(path);
    Tcl_DecrRefCount(transPtr);

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

    if (tclPlatform == TCL_PLATFORM_WINDOWS) {
        register char *p;
        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.
 *
 *----------------------------------------------------------------------
 */

const char *
TclGetExtension(
    const char *name)           /* File name to parse. */
{
    const 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_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 const char *
DoTildeSubst(
    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. */
{
    const 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", 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",
                    NULL);
        }
        return NULL;
    }
    return Tcl_DStringValue(resultPtr);
}

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

    globFlags = 0;
    join = 0;
    dir = PATH_NONE;
    typePtr = NULL;
    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 |= TCL_GLOBMODE_NO_COMPLAIN;
            break;
        case GLOB_DIR:                          /* -dir */
            if (i == (objc-1)) {
                Tcl_SetObjResult(interp, Tcl_NewStringObj(
                        "missing argument to \"-directory\"", -1));
                return TCL_ERROR;
            }
            if (dir != PATH_NONE) {
                Tcl_SetObjResult(interp, Tcl_NewStringObj(
                        "\"-directory\" cannot be used with \"-path\"", -1));
                return TCL_ERROR;
            }
            dir = PATH_DIR;
            globFlags |= TCL_GLOBMODE_DIR;
            pathOrDir = objv[i+1];
            i++;
            break;
        case GLOB_JOIN:                         /* -join */
            join = 1;
            break;
        case GLOB_TAILS:                                /* -tails */
            globFlags |= TCL_GLOBMODE_TAILS;
            break;
        case GLOB_PATH:                         /* -path */
            if (i == (objc-1)) {
                Tcl_SetObjResult(interp, Tcl_NewStringObj(
                        "missing argument to \"-path\"", -1));
                return TCL_ERROR;
            }
            if (dir != PATH_NONE) {
                Tcl_SetObjResult(interp, Tcl_NewStringObj(
                        "\"-path\" cannot be used with \"-directory\"", -1));
                return TCL_ERROR;
            }
            dir = PATH_GENERAL;
            pathOrDir = objv[i+1];
            i++;
            break;
        case GLOB_TYPE:                         /* -types */
            if (i == (objc-1)) {
                Tcl_SetObjResult(interp, Tcl_NewStringObj(
                        "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;
        }
    }

  endOfForLoop:
    if (objc - i < 1) {
        Tcl_WrongNumArgs(interp, 1, objv, "?switches? name ?name ...?");
        return TCL_ERROR;
    }
    if ((globFlags & TCL_GLOBMODE_TAILS) && (pathOrDir == NULL)) {
        Tcl_AppendResult(interp,
                "\"-tails\" must be used with either "
                "\"-directory\" or \"-path\"", NULL);
        return TCL_ERROR;
    }

    separators = NULL;          /* lint. */
    switch (tclPlatform) {
    case TCL_PLATFORM_UNIX:
        separators = "/";
        break;
    case TCL_PLATFORM_WINDOWS:
        separators = "/\\:";
        break;
    }

    if (dir == PATH_GENERAL) {
        int pathlength;
        char *last;
        char *first = Tcl_GetStringFromObj(pathOrDir,&pathlength);

        /*
         * Find the last path separator in the path
         */

        last = first + pathlength;
        for (; last != first; last--) {
            if (strchr(separators, *(last-1)) != NULL) {
                break;
            }
        }

        if (last == first + pathlength) {
            /*
             * It's really a directory.
             */

            dir = PATH_DIR;

        } else {
            Tcl_DString pref;
            char *search, *find;
            Tcl_DStringInit(&pref);
            if (last == first) {
                /*
                 * The whole thing is a prefix. This means we must remove any
                 * 'tails' flag too, since it is irrelevant now (the same
                 * effect will happen without it), but in particular its use
                 * in TclGlob requires a non-NULL pathOrDir.
                 */

                Tcl_DStringAppend(&pref, first, -1);
                globFlags &= ~TCL_GLOBMODE_TAILS;
                pathOrDir = NULL;
            } else {
                /*
                 * Have to split off the end.
                 */

                Tcl_DStringAppend(&pref, last, first+pathlength-last);
                pathOrDir = Tcl_NewStringObj(first, last-first-1);

                /*
                 * We must ensure that we haven't cut off too much, and turned
                 * a valid path like '/' or 'C:/' into an incorrect path like
                 * '' or 'C:'. The way we do this is to add a separator if
                 * there are none presently in the prefix.
                 */

                if (strpbrk(Tcl_GetString(pathOrDir), "\\/") == NULL) {
                    Tcl_AppendToObj(pathOrDir, last-1, 1);
                }
            }

            /*
             * 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 (pathOrDir != NULL) {
        Tcl_IncrRefCount(pathOrDir);
    }

    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 = (Tcl_GlobTypeData*)
                TclStackAlloc(interp,sizeof(Tcl_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. We reset the 'join' flag to zero, since we
                 * haven't yet made use of it.
                 */

            badTypesArg:
                TclNewObj(resultPtr);
                Tcl_AppendToObj(resultPtr, "bad argument to \"-types\": ", -1);
                Tcl_AppendObjToObj(resultPtr, look);
                Tcl_SetObjResult(interp, resultPtr);
                result = TCL_ERROR;
                join = 0;
                goto endOfGlob;

            badMacTypesArg:
                Tcl_SetObjResult(interp, Tcl_NewStringObj(
                        "only one MacOS type or creator argument"
                        " to \"-types\" allowed", -1));
                result = TCL_ERROR;
                join = 0;
                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;
    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 & TCL_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 \"", NULL);
            if (join) {
                Tcl_AppendResult(interp, Tcl_DStringValue(&prefix), NULL);
            } else {
                const char *sep = "";
                for (i = 0; i < objc; i++) {
                    string = Tcl_GetString(objv[i]);
                    Tcl_AppendResult(interp, sep, string, NULL);
                    sep = " ";
                }
            }
            Tcl_AppendResult(interp, "\"", NULL);
            result = TCL_ERROR;
        }
    }

  endOfGlob:
    if (join || (dir == PATH_GENERAL)) {
        Tcl_DStringFree(&prefix);
    }
    if (pathOrDir != NULL) {
        Tcl_DecrRefCount(pathOrDir);
    }
    if (globTypes != NULL) {
        if (globTypes->macType != NULL) {
            Tcl_DecrRefCount(globTypes->macType);
        }
        if (globTypes->macCreator != NULL) {
            Tcl_DecrRefCount(globTypes->macCreator);
        }
        TclStackFree(interp, globTypes);
    }
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * TclGlob --
 *
 *      This procedure prepares arguments for the DoGlob call. It sets the
 *      separator string based on the platform, performs * tilde substitution,
 *      and calls DoGlob.
 *
 *      The interpreter's result, on entry to this function, must be a valid
 *      Tcl list (e.g. it could be empty), since we will lappend any new
 *      results to that list. If it is not a valid list, this function will
 *      fail to do anything very meaningful.
 *
 *      Note that if globFlags contains 'TCL_GLOBMODE_TAILS' then pathPrefix
 *      cannot be NULL (it is only allowed with -dir or -path).
 *
 * 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 DoGlob) holds all of the file names given by the pattern and
 *      pathPrefix arguments. After an error the result in interp will hold
 *      an error message.
 *
 * Side effects:
 *      The 'pattern' is written to.
 *
 *----------------------------------------------------------------------
 */

        /* ARGSUSED */
int
TclGlob(
    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. */
    Tcl_Obj *pathPrefix,        /* Path prefix to glob pattern, if non-null,
                                 * which is considered literally. */
    int globFlags,              /* Stores or'ed combination of flags */
    Tcl_GlobTypeData *types)    /* Struct containing acceptable types. May be
                                 * NULL. */
{
    const char *separators;
    const char *head;
    char *tail, *start;
    int result;
    Tcl_Obj *filenamesObj, *savedResultObj;

    separators = NULL;          /* lint. */
    switch (tclPlatform) {
    case TCL_PLATFORM_UNIX:
        separators = "/";
        break;
    case TCL_PLATFORM_WINDOWS:
        separators = "/\\:";
        break;
    }

    if (pathPrefix == NULL) {
        char c;
        Tcl_DString buffer;
        Tcl_DStringInit(&buffer);

        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.
             */

            c = *tail;
            *tail = '\0';
            head = DoTildeSubst(interp, start+1, &buffer);
            *tail = c;
            if (head == NULL) {
                return TCL_ERROR;
            }
            if (head != Tcl_DStringValue(&buffer)) {
                Tcl_DStringAppend(&buffer, head, -1);
            }
            pathPrefix = Tcl_NewStringObj(Tcl_DStringValue(&buffer),
                    Tcl_DStringLength(&buffer));
            Tcl_IncrRefCount(pathPrefix);
            globFlags |= TCL_GLOBMODE_DIR;
            if (c != '\0') {
                tail++;
            }
            Tcl_DStringFree(&buffer);
        } else {
            tail = pattern;
        }
    } else {
        Tcl_IncrRefCount(pathPrefix);
        tail = pattern;
    }

    /*
     * Handling empty path prefixes with glob patterns like 'C:' or
     * 'c:////////' is a pain on Windows if we leave it too late, since these
     * aren't really patterns at all! We therefore check the head of the
     * pattern now for such cases, if we don't have an unquoted prefix yet.
     *
     * Similarly on Unix with '/' at the head of the pattern -- it just
     * indicates the root volume, so we treat it as such.
     */

    if (tclPlatform == TCL_PLATFORM_WINDOWS) {
        if (pathPrefix == NULL && tail[0] != '\0' && tail[1] == ':') {
            char *p = tail + 1;
            pathPrefix = Tcl_NewStringObj(tail, 1);
            while (*p != '\0') {
                char c = p[1];
                if (*p == '\\') {
                    if (strchr(separators, c) != NULL) {
                        if (c == '\\') {
                            c = '/';
                        }
                        Tcl_AppendToObj(pathPrefix, &c, 1);
                        p++;
                    } else {
                        break;
                    }
                } else if (strchr(separators, *p) != NULL) {
                    Tcl_AppendToObj(pathPrefix, p, 1);
                } else {
                    break;
                }
                p++;
            }
            tail = p;
            Tcl_IncrRefCount(pathPrefix);
        } else if (pathPrefix == NULL && (tail[0] == '/'
                || (tail[0] == '\\' && tail[1] == '\\'))) {
            int driveNameLen;
            Tcl_Obj *driveName;
            Tcl_Obj *temp = Tcl_NewStringObj(tail, -1);
            Tcl_IncrRefCount(temp);

            switch (TclGetPathType(temp, NULL, &driveNameLen, &driveName)) {
            case TCL_PATH_VOLUME_RELATIVE: {
                /*
                 * Volume relative path which is equivalent to a path in the
                 * root of the cwd's volume. We will actually return
                 * non-volume-relative paths here. i.e. 'glob /foo*' will
                 * return 'C:/foobar'. This is much the same as globbing for a
                 * path with '\\' will return one with '/' on Windows.
                 */

                Tcl_Obj *cwd = Tcl_FSGetCwd(interp);

                if (cwd == NULL) {
                    Tcl_DecrRefCount(temp);
                    return TCL_ERROR;
                }
                pathPrefix = Tcl_NewStringObj(Tcl_GetString(cwd), 3);
                Tcl_DecrRefCount(cwd);
                if (tail[0] == '/') {
                    tail++;
                } else {
                    tail+=2;
                }
                Tcl_IncrRefCount(pathPrefix);
                break;
            }
            case TCL_PATH_ABSOLUTE:
                /*
                 * Absolute, possibly network path //Machine/Share. Use that
                 * as the path prefix (it already has a refCount).
                 */

                pathPrefix = driveName;
                tail += driveNameLen;
                break;
            case TCL_PATH_RELATIVE:
                /* Do nothing */
                break;
            }
            Tcl_DecrRefCount(temp);
        }

        /*
         * ':' no longer needed as a separator. It is only relevant to the
         * beginning of the path.
         */

        separators = "/\\";

    } else if (tclPlatform == TCL_PLATFORM_UNIX) {
        if (pathPrefix == NULL && tail[0] == '/') {
            pathPrefix = Tcl_NewStringObj(tail, 1);
            tail++;
            Tcl_IncrRefCount(pathPrefix);
        }
    }

    /*
     * Finally if we still haven't managed to generate a path prefix, check if
     * the path starts with a current volume.
     */

    if (pathPrefix == NULL) {
        int driveNameLen;
        Tcl_Obj *driveName;
        if (TclFSNonnativePathType(tail, (int) strlen(tail), NULL,
                &driveNameLen, &driveName) == TCL_PATH_ABSOLUTE) {
            pathPrefix = driveName;
            tail += driveNameLen;
        }
    }

    /*
     * To process a [glob] invokation, this function may be called multiple
     * times. Each time, the previously discovered filenames are in the
     * interpreter result. We stash that away here so the result is free for
     * error messsages.
     */

    savedResultObj = Tcl_GetObjResult(interp);
    Tcl_IncrRefCount(savedResultObj);
    Tcl_ResetResult(interp);
    TclNewObj(filenamesObj);
    Tcl_IncrRefCount(filenamesObj);

    /*
     * Now we do the actual globbing, adding filenames as we go to buffer in
     * filenamesObj
     */

    if (*tail == '\0' && pathPrefix != NULL) {
        /*
         * An empty pattern.  This means 'pathPrefix' is actually
         * a full path of a file/directory we want to simply check
         * for existence and type.
         */
        if (types == NULL) {
            /* 
             * We just want to check for existence.  In this case we
             * make it easy on Tcl_FSMatchInDirectory and its
             * sub-implementations by not bothering them (even though
             * they should support this situation) and we just use the
             * simple existence check with Tcl_FSAccess.
             */
            if (Tcl_FSAccess(pathPrefix, F_OK) == 0) {
                Tcl_ListObjAppendElement(interp, filenamesObj, pathPrefix);
            }
            result = TCL_OK;
        } else {
            /* 
             * We want to check for the correct type.  Tcl_FSMatchInDirectory
             * is documented to do this for us, if we give it a NULL pattern.
             */
            result = Tcl_FSMatchInDirectory(interp, filenamesObj, pathPrefix,
                    NULL, types);
        }
    } else {
        result = DoGlob(interp, filenamesObj, separators, pathPrefix,
                globFlags & TCL_GLOBMODE_DIR, tail, types);
    }

    /*
     * Check for errors...
     */

    if (result != TCL_OK) {
        TclDecrRefCount(filenamesObj);
        TclDecrRefCount(savedResultObj);
        if (pathPrefix != NULL) {
            Tcl_DecrRefCount(pathPrefix);
        }
        return result;
    }

    /*
     * If we only want the tails, we must strip off the prefix now. It may
     * seem more efficient to pass the tails flag down into DoGlob,
     * Tcl_FSMatchInDirectory, but those functions are continually adjusting
     * the prefix as the various pieces of the pattern are assimilated, so
     * that would add a lot of complexity to the code. This way is a little
     * slower (when the -tails flag is given), but much simpler to code.
     *
     * We do it by rewriting the result list in-place.
     */

    if (globFlags & TCL_GLOBMODE_TAILS) {
        int objc, i;
        Tcl_Obj **objv;
        int prefixLen;
        const char *pre;

        /*
         * If this length has never been set, set it here.
         */

        if (pathPrefix == NULL) {
            Tcl_Panic("Called TclGlob with TCL_GLOBMODE_TAILS and pathPrefix==NULL");
        }
        
        pre = Tcl_GetStringFromObj(pathPrefix, &prefixLen);
        if (prefixLen > 0
                && (strchr(separators, pre[prefixLen-1]) == NULL)) {
            /*
             * If we're on Windows and the prefix is a volume relative one
             * like 'C:', then there won't be a path separator in between, so
             * no need to skip it here.
             */

            if ((tclPlatform != TCL_PLATFORM_WINDOWS) || (prefixLen != 2)
                    || (pre[1] != ':')) {
                prefixLen++;
            }
        }

        Tcl_ListObjGetElements(NULL, filenamesObj, &objc, &objv);
        for (i = 0; i< objc; i++) {
            int len;
            char *oldStr = Tcl_GetStringFromObj(objv[i], &len);
            Tcl_Obj* elems[1];

            if (len == prefixLen) {
                if ((pattern[0] == '\0')
                        || (strchr(separators, pattern[0]) == NULL)) {
                    TclNewLiteralStringObj(elems[0], ".");
                } else {
                    TclNewLiteralStringObj(elems[0], "/");
                }
            } else {
                elems[0] = Tcl_NewStringObj(oldStr+prefixLen, len-prefixLen);
            }
            Tcl_ListObjReplace(interp, filenamesObj, i, 1, 1, elems);
        }
    }

    /*
     * Now we have a list of discovered filenames in filenamesObj and a list
     * of previously discovered (saved earlier from the interpreter result) in
     * savedResultObj. Merge them and put them back in the interpreter result.
     */

    if (Tcl_IsShared(savedResultObj)) {
        TclDecrRefCount(savedResultObj);
        savedResultObj = Tcl_DuplicateObj(savedResultObj);
        Tcl_IncrRefCount(savedResultObj);
    }
    if (Tcl_ListObjAppendList(interp, savedResultObj, filenamesObj) != TCL_OK){
        result = TCL_ERROR;
    } else {
        Tcl_SetObjResult(interp, savedResultObj);
    }
    TclDecrRefCount(savedResultObj);
    TclDecrRefCount(filenamesObj);
    if (pathPrefix != NULL) {
        Tcl_DecrRefCount(pathPrefix);
    }

    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(
    char **stringPtr,           /* Pointer string to check. */
    int match)                  /* 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;
}

/*
 *----------------------------------------------------------------------
 *
 * DoGlob --
 *
 *      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 and the pattern. The directory and remainder are assumed to
 *      be native format paths. The prefix contained in 'pathPtr' is either a
 *      directory or path from which to start the search (or NULL). If pathPtr
 *      is NULL, then the pattern must not start with an absolute path
 *      specification (that case should be handled by moving the absolute path
 *      prefix into pathPtr before calling DoGlob).
 *
 * 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 remaining
 *      arguments. After an error the result in interp will hold an error
 *      message.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

static int
DoGlob(
    Tcl_Interp *interp,         /* Interpreter to use for error reporting
                                 * (e.g. unmatched brace). */
    Tcl_Obj *matchesObj,        /* Unshared list object in which to place all
                                 * resulting filenames. Caller allocates and
                                 * deallocates; DoGlob must not touch the
                                 * refCount of this object. */
    const char *separators, /* String containing separator characters that
                                 * should be used to identify globbing
                                 * boundaries. */
    Tcl_Obj *pathPtr,           /* Completely expanded prefix. */
    int flags,                  /* If non-zero then pathPtr is a directory */
    char *pattern,              /* The pattern to match against. Must not be a
                                 * pointer to a static string. */
    Tcl_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;
    Tcl_Obj *joinedPtr;

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

    count = 0;
    name = pattern;
    for (; *pattern != '\0'; pattern++) {
        if (*pattern == '\\') {
            /*
             * If the first character is escaped, either we have a directory
             * separator, or we have any other character. In the latter case
             * the rest is a pattern, and we must break from the loop. This
             * is particularly important on Windows where '\' is both the
             * escaping character and a directory separator.
             */

            if (strchr(separators, pattern[1]) != NULL) {
                pattern++;
            } else {
                break;
            }
        } else if (strchr(separators, *pattern) == NULL) {
            break;
        }
        count++;
    }

    /*
     * This block of code is not exercised by the Tcl test suite as of Tcl
     * 8.5a0. Simplifications to the calling paths suggest it may not be
     * necessary any more, since path separators are handled elsewhere. It is
     * left in place in case new bugs are reported.
     */

#if 0 /* PROBABLY_OBSOLETE */
    /*
     * Deal with path separators.
     */

    if (pathPtr == NULL) {
        /*
         * Length used to be the length of the prefix, and lastChar the
         * lastChar of the prefix. But, none of this is used any more.
         */

        int length = 0;
        char lastChar = 0;

        switch (tclPlatform) {
        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(&append, ":", 1);
                if (count > 1) {
                    Tcl_DStringAppend(&append, "/", 1);
                }
            } else if ((*pattern != '\0') && (((length > 0)
                    && (strchr(separators, lastChar) == NULL))
                    || ((length == 0) && (count > 0)))) {
                Tcl_DStringAppend(&append, "/", 1);
                if ((length == 0) && (count > 1)) {
                    Tcl_DStringAppend(&append, "/", 1);
                }
            }

            break;
        case TCL_PLATFORM_UNIX:
            /*
             * Add a separator if this is the first absolute element, or a
             * later relative element.
             */

            if ((*pattern != '\0') && (((length > 0)
                    && (strchr(separators, lastChar) == NULL))
                    || ((length == 0) && (count > 0)))) {
                Tcl_DStringAppend(&append, "/", 1);
            }
            break;
        }
    }
#endif /* PROBABLY_OBSOLETE */

    /*
     * 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 = pattern; *p != '\0'; p++) {
        if (quoted) {
            quoted = 0;

        } else if (*p == '\\') {
            quoted = 1;
            if (strchr(separators, p[1]) != NULL) {
                /*
                 * Quoted directory separator.
                 */
                break;
            }

        } else if (strchr(separators, *p) != NULL) {
            /*
             * Unquoted directory separator.
             */
            break;

        } else if (*p == '{') {
            openBrace = p;
            p++;
            if (SkipToChar(&p, '}')) {
                /*
                 * Balanced braces.
                 */

                closeBrace = p;
                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 DoGlob.
         */

        Tcl_DStringAppend(&newName, pattern, openBrace-pattern);
        baseLength = Tcl_DStringLength(&newName);
        *closeBrace = '\0';
        for (p = openBrace; p != closeBrace; ) {
            p++;
            element = p;
            SkipToChar(&p, ',');
            Tcl_DStringSetLength(&newName, baseLength);
            Tcl_DStringAppend(&newName, element, p-element);
            Tcl_DStringAppend(&newName, closeBrace+1, -1);
            result = DoGlob(interp, matchesObj, separators, pathPtr, flags,
                    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
     * pattern if p is pointing at the end of the string.
     *
     * If we find any globbing characters, then we must call
     * Tcl_FSMatchInDirectory. If we're at the end of the string, then that's
     * all we need to do. If we're not at the end of the string, then we must
     * recurse, so we do that below.
     *
     * Alternatively, if there are no globbing characters then again there are
     * two cases. If we're at the end of the string, we just need to check for
     * the given path's existence and type. If we're not at the end of the
     * string, we recurse.
     */

    if (*p != '\0') {
        /*
         * Note that we are modifying the string in place. This won't work if
         * the string is a static.
         */

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

    if (firstSpecialChar != NULL) {
        /*
         * Look for matching files in the given directory. The implementation
         * of this function is filesystem specific. For each file that
         * matches, it will add the match onto the resultPtr given.
         */

        static Tcl_GlobTypeData dirOnly = {
            TCL_GLOB_TYPE_DIR, 0, NULL, NULL
        };
        char save = *p;
        Tcl_Obj* subdirsPtr;

        if (*p == '\0') {
            return Tcl_FSMatchInDirectory(interp, matchesObj, pathPtr,
                    pattern, types);
        }

        /*
         * We do the recursion ourselves. This makes implementing
         * Tcl_FSMatchInDirectory for each filesystem much easier.
         */

        *p = '\0';
        TclNewObj(subdirsPtr);
        Tcl_IncrRefCount(subdirsPtr);
        result = Tcl_FSMatchInDirectory(interp, subdirsPtr, pathPtr,
                pattern, &dirOnly);
        *p = save;
        if (result == TCL_OK) {
            int subdirc, i;
            Tcl_Obj **subdirv;

            result = Tcl_ListObjGetElements(interp, subdirsPtr,
                    &subdirc, &subdirv);
            for (i=0; result==TCL_OK && i<subdirc; i++) {
                result = DoGlob(interp, matchesObj, separators, subdirv[i],
                        1, p+1, types);
            }
        }
        TclDecrRefCount(subdirsPtr);
        return result;
    }

    /*
     * We reach here with no pattern char in current section
     */

    if (*p == '\0') {
        /*
         * This is the code path reached by a command like 'glob foo'.
         *
         * There are no more wildcards in the pattern and no more unprocessed
         * characters in the pattern, so now we can construct the path, and
         * pass it to Tcl_FSMatchInDirectory with an empty pattern to verify
         * the existence of the file and check it is of the correct type (if a
         * 'types' flag it given -- if no such flag was given, we could just
         * use 'Tcl_FSLStat', but for simplicity we keep to a common
         * approach).
         */

        int length;
        Tcl_DString append;

        Tcl_DStringInit(&append);
        Tcl_DStringAppend(&append, pattern, p-pattern);

        if (pathPtr != NULL) {
            (void) Tcl_GetStringFromObj(pathPtr, &length);
        } else {
            length = 0;
        }

        switch (tclPlatform) {
        case TCL_PLATFORM_WINDOWS:
            if (length == 0 && (Tcl_DStringLength(&append) == 0)) {
                if (((*name == '\\') && (name[1] == '/' ||
                        name[1] == '\\')) || (*name == '/')) {
                    Tcl_DStringAppend(&append, "/", 1);
                } else {
                    Tcl_DStringAppend(&append, ".", 1);
                }
            }

#if defined(__CYGWIN__) && defined(__WIN32__)
            {
                extern int cygwin_conv_to_win32_path(const char *, char *);
                char winbuf[MAX_PATH+1];

                cygwin_conv_to_win32_path(Tcl_DStringValue(&append), winbuf);
                Tcl_DStringFree(&append);
                Tcl_DStringAppend(&append, winbuf, -1);
            }
#endif /* __CYGWIN__ && __WIN32__ */
            break;

        case TCL_PLATFORM_UNIX:
            if (length == 0 && (Tcl_DStringLength(&append) == 0)) {
                if ((*name == '\\' && name[1] == '/') || (*name == '/')) {
                    Tcl_DStringAppend(&append, "/", 1);
                } else {
                    Tcl_DStringAppend(&append, ".", 1);
                }
            }
            break;
        }

        /*
         * Common for all platforms.
         */

        if (pathPtr == NULL) {
            joinedPtr = Tcl_NewStringObj(Tcl_DStringValue(&append),
                    Tcl_DStringLength(&append));
        } else if (flags) {
            joinedPtr = TclNewFSPathObj(pathPtr, Tcl_DStringValue(&append),
                    Tcl_DStringLength(&append));
        } else {
            joinedPtr = Tcl_DuplicateObj(pathPtr);
            if (strchr(separators, Tcl_DStringValue(&append)[0]) == NULL) {
                /*
                 * The current prefix must end in a separator.
                 */

                int len;
                const char *joined = Tcl_GetStringFromObj(joinedPtr,&len);

                if (strchr(separators, joined[len-1]) == NULL) {
                    Tcl_AppendToObj(joinedPtr, "/", 1);
                }
            }
            Tcl_AppendToObj(joinedPtr, Tcl_DStringValue(&append),
                    Tcl_DStringLength(&append));
        }
        Tcl_IncrRefCount(joinedPtr);
        Tcl_DStringFree(&append);
        Tcl_FSMatchInDirectory(interp, matchesObj, joinedPtr, NULL, types);
        Tcl_DecrRefCount(joinedPtr);
        return TCL_OK;
    }

    /*
     * If it's not the end of the string, we must recurse
     */

    if (pathPtr == NULL) {
        joinedPtr = Tcl_NewStringObj(pattern, p-pattern);
    } else if (flags) {
        joinedPtr = TclNewFSPathObj(pathPtr, pattern, p-pattern);
    } else {
        joinedPtr = Tcl_DuplicateObj(pathPtr);
        if (strchr(separators, pattern[0]) == NULL) {
            /*
             * The current prefix must end in a separator, unless this is a
             * volume-relative path. In particular globbing in Windows shares,
             * when not using -dir or -path, e.g. 'glob [file join
             * //machine/share/subdir *]' requires adding a separator here.
             * This behaviour is not currently tested for in the test suite.
             */

            int len;
            const char *joined = Tcl_GetStringFromObj(joinedPtr,&len);

            if (strchr(separators, joined[len-1]) == NULL) {
                if (Tcl_FSGetPathType(pathPtr) != TCL_PATH_VOLUME_RELATIVE) {
                    Tcl_AppendToObj(joinedPtr, "/", 1);
                }
            }
        }
        Tcl_AppendToObj(joinedPtr, pattern, p-pattern);
    }

    Tcl_IncrRefCount(joinedPtr);
    result = DoGlob(interp, matchesObj, separators, joinedPtr, 1, p, types);
    Tcl_DecrRefCount(joinedPtr);

    return result;
}

/*
 *---------------------------------------------------------------------------
 *
 * Tcl_AllocStatBuf --
 *
 *      This procedure allocates a Tcl_StatBuf on the heap. It exists so that
 *      extensions may be used unchanged on systems where largefile support is
 *      optional.
 *
 * Results:
 *      A pointer to a Tcl_StatBuf which may be deallocated by being passed to
 *      ckfree().
 *
 * Side effects:
 *      None.
 *
 *---------------------------------------------------------------------------
 */

Tcl_StatBuf *
Tcl_AllocStatBuf(void)
{
    return (Tcl_StatBuf *) ckalloc(sizeof(Tcl_StatBuf));
}

/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78
 * End:
 */