path: root/generic/tclFileName.c

/* 
 * 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 1.56 2004/09/27 15:00:26 vincentdarley 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 _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 int		SkipToChar _ANSI_ARGS_((char **stringPtr, int match));
static Tcl_Obj*		SplitWinPath _ANSI_ARGS_((CONST char *path));
static Tcl_Obj*		SplitUnixPath _ANSI_ARGS_((CONST char *path));
static int              DoGlob _ANSI_ARGS_((Tcl_Interp *interp, 
			    char *separators, Tcl_Obj *pathPtr, 
			    int flags, char *pattern, Tcl_GlobTypeData *types));


/*
 *----------------------------------------------------------------------
 *
 * 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 */
{
    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] != '\\') {
	    Tcl_DStringSetLength(resultPtr, offset);
	    *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];
	}
	Tcl_DStringSetLength(resultPtr, offset);
	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 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 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;
	if (path[0] == 'c' && path[1] == 'o') {
	    if (path[2] == 'm' && path[3] >= '1' && path[3] <= '9') {
		/* May have match for 'com[1-9]:?', 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[3] == '\0') {
		/* Have match for 'con' */
		abs = 3;
	    }
	} else if (path[0] == 'l' && path[1] == 'p' && path[2] == 't') {
	    if (path[3] >= '1' && path[3] <= '9') {
		/* May have match for 'lpt[1-9]:?' */
		if (path[4] == '\0') {
		    abs = 4;
		} else if (path [4] == ':' && path[5] == '\0') {
		    abs = 5;
		}
	    }
	} else if (path[0] == 'p' && path[1] == 'r' 
		   && path[2] == 'n' && path[3] == '\0') {
	    /* Have match for 'prn' */
	    abs = 3;
	} else if (path[0] == 'n' && path[1] == 'u' 
		   && path[2] == 'l' && path[3] == '\0') {
	    /* Have match for 'nul' */
	    abs = 3;
	} else if (path[0] == 'a' && path[1] == 'u' 
		   && path[2] == 'x' && path[3] == '\0') {
	    /* Have match for 'aux' */
	    abs = 3;
	}
	if (abs != 0) {
	    *typePtr = TCL_PATH_ABSOLUTE;
	    Tcl_DStringSetLength(resultPtr, offset);
	    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(path)
    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(pathPtr, driveNameLengthPtr, driveNameRef)
    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(pathPtr, lenPtr)
    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(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. */
    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((VOID *) p, (VOID *) 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;
	while ((*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(path)
    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)) {
		nextElt = Tcl_NewStringObj("./",2);
		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(path)
    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 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[0] == '~') && (elementStart != path)) {
		nextElt = Tcl_NewStringObj("./",2);
		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(pathPtr, objc, objv)
    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(prefix, joining)
    Tcl_Obj *prefix;
    char* joining;
{
    int length, needsSep;
    char *dest, *p, *start;
    
    start = Tcl_GetStringFromObj(prefix, &length);

    /*
     * Remove the ./ from tilde prefixed elements unless
     * it is the first component.
     */
    
    p = joining;
    
    if (length != 0) {
	if ((p[0] == '.') && (p[1] == '/') && (p[2] == '~')) {
	    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') {
			if (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(argc, argv, resultPtr)
    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(interp, name, bufferPtr)
    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(name)
    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(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. */
{
    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", (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 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(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, length, join, dir, result;
    char *string, *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_SetObjResult(interp, Tcl_NewStringObj(
	  "\"-tails\" must be used with either \"-directory\" or \"-path\"",
	  -1));
	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*) ckalloc(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:
		resultPtr = Tcl_GetObjResult(interp);
		Tcl_AppendToObj(resultPtr, "bad argument to \"-types\": ", -1);
		Tcl_AppendObjToObj(resultPtr, look);
		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 \"", (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 (pathOrDir != NULL) {
	Tcl_DecrRefCount(pathOrDir);
    }
    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 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, unless
 *	the 'TCL_GLOBMODE_NO_COMPLAIN' flag was given, in which case
 *	an error results in a TCL_OK return leaving the interpreter's
 *	result unmodified.
 *
 * Side effects:
 *	The 'pattern' is written to.
 *
 *----------------------------------------------------------------------
 */

	/* ARGSUSED */
int
TclGlob(interp, pattern, pathPrefix, 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. */
    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. */
{
    char *separators;
    CONST char *head;
    char *tail, *start;
    int result;
    Tcl_Obj *oldResult;
    
    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';
	    if (globFlags & TCL_GLOBMODE_NO_COMPLAIN) {
		/* 
		 * We will ignore any error message here, and we
		 * don't want to mess up the interpreter's result.
		 */
		head = DoTildeSubst(NULL, start+1, &buffer);
	    } else {
		head = DoTildeSubst(interp, start+1, &buffer);
	    }
	    *tail = c;
	    if (head == NULL) {
		if (globFlags & TCL_GLOBMODE_NO_COMPLAIN) {
		    return TCL_OK;
		} else {
		    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);
                        if (globFlags & TCL_GLOBMODE_NO_COMPLAIN) {
                            return TCL_OK;
                        } else {
                            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 */
		}
            }
            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;
	}
    }
    
    /* 
     * We need to get the old result, in case it is over-written
     * below when we still need it.
     */
    oldResult = Tcl_GetObjResult(interp);
    Tcl_IncrRefCount(oldResult);
    Tcl_ResetResult(interp);

    if (*tail == '\0' && pathPrefix != NULL) {
	/* 
	 * An empty pattern 
	 */
	result = Tcl_FSMatchInDirectory(interp, Tcl_GetObjResult(interp), 
					pathPrefix, NULL, types);
	
    } else {
	result = DoGlob(interp, separators, pathPrefix, 
			globFlags & TCL_GLOBMODE_DIR, tail, types);
    }
    
    if (result != TCL_OK) {
	if (globFlags & TCL_GLOBMODE_NO_COMPLAIN) {
	    /* Put back the old result and reset the return code */
	    Tcl_SetObjResult(interp, oldResult);
	    result = TCL_OK;
	}
    } else {
	/* 
	 * Now we must concatenate the 'oldResult' and the current
	 * result, and then place that into the interpreter.
	 * 
	 * 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.
	 */

	/* 
	 * Ensure sole ownership.  We also assume that oldResult
	 * is a valid list in the code below.
	 */
	if (Tcl_IsShared(oldResult)) {
	    Tcl_DecrRefCount(oldResult);
	    oldResult = Tcl_DuplicateObj(oldResult);
	    Tcl_IncrRefCount(oldResult);
	}

	if (globFlags & TCL_GLOBMODE_TAILS) {
	    int objc, i;
	    Tcl_Obj **objv;
	    int prefixLen;
	    
	    /* If this length has never been set, set it here */
	    CONST char *pre = Tcl_GetStringFromObj(pathPrefix, &prefixLen);
	    if (prefixLen > 0) {
		if (strchr(separators, pre[prefixLen-1]) == NULL) {
		    prefixLen++;
		}
	    }

	    Tcl_ListObjGetElements(NULL, Tcl_GetObjResult(interp), 
				   &objc, &objv);
	    for (i = 0; i< objc; i++) {
		Tcl_Obj* elt;
		int len;
		char *oldStr = Tcl_GetStringFromObj(objv[i],&len);
		if (len == prefixLen) {
		    if ((pattern[0] == '\0')
			|| (strchr(separators, pattern[0]) == NULL)) {
			elt = Tcl_NewStringObj(".",1);
		    } else {
			elt = Tcl_NewStringObj("/",1);
		    }
		} else {
		    elt = Tcl_NewStringObj(oldStr + prefixLen, 
						len - prefixLen);
		}
		Tcl_ListObjAppendElement(interp, oldResult, elt);
	    }
	} else {
	    Tcl_ListObjAppendList(interp, oldResult, Tcl_GetObjResult(interp));
	}
	Tcl_SetObjResult(interp, oldResult);
    }
    /* 
     * Release our temporary copy.  All code paths above must
     * end here so we free our reference.
     */
    Tcl_DecrRefCount(oldResult);
    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. */
    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(interp, separators, pathPtr, flags, pattern, 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_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;

    /*
     * 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
    /*
     * 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
    
    /*
     * 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 TclDoGlob.
	 */

	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, 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) {
	int ret;

	/*
	 * 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.
	 */
	if (*p == '\0') {
	    ret = Tcl_FSMatchInDirectory(interp, Tcl_GetObjResult(interp), 
					 pathPtr, pattern, types);
	} else {
	    Tcl_Obj* resultPtr;

	    /* 
	     * We do the recursion ourselves.  This makes implementing
	     * Tcl_FSMatchInDirectory for each filesystem much easier.
	     */
	    Tcl_GlobTypeData dirOnly = { TCL_GLOB_TYPE_DIR, 0, NULL, NULL };
	    char save = *p;
	    
	    *p = '\0';
	    resultPtr = Tcl_NewListObj(0, NULL);
	    ret = Tcl_FSMatchInDirectory(interp, resultPtr, 
					 pathPtr, pattern, &dirOnly);
	    *p = save;
	    if (ret == TCL_OK) {
		int resLength;
		ret = Tcl_ListObjLength(interp, resultPtr, &resLength);
		if (ret == TCL_OK) {
		    int i;
		    for (i =0; i< resLength; i++) {
			Tcl_Obj *elt;
			
			Tcl_ListObjIndex(interp, resultPtr, i, &elt);
			ret = DoGlob(interp, separators, elt, 1, p+1, types);
			if (ret != TCL_OK) {
			    break;
			}
		    }
		}
	    }
	    Tcl_DecrRefCount(resultPtr);
	}
	return ret;
    } else {
	/* 
	 * We reach here with no pattern char in current section 
	 */
	
	if (*p != '\0') {
	    Tcl_Obj *joined;
	    int ret;
	    
	    /* 
	     * If it's not the end of the string, we must recurse 
	     */
	    if (pathPtr != NULL) {
		if (flags) {
		    joined = TclNewFSPathObj(pathPtr, pattern, p-pattern);
		} else {
		    joined = Tcl_DuplicateObj(pathPtr);
		    Tcl_AppendToObj(joined, pattern, p-pattern);
		}
	    } else {
		joined = Tcl_NewStringObj(pattern, p-pattern);
	    }
	    Tcl_IncrRefCount(joined);
	    ret = DoGlob(interp, separators, joined, 1, p, types);
	    Tcl_DecrRefCount(joined);
	    return ret;
	} else {
	    /*
	     * 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).
	     */

	    Tcl_Obj *joined;
	    int length;
	    Tcl_DString append;
	    
	    Tcl_DStringInit(&append);
	    Tcl_DStringAppend(&append, pattern, p-pattern);

	    if (pathPtr != NULL) {
		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 
			_ANSI_ARGS_((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) {
		if (flags) {
		    joined = TclNewFSPathObj(pathPtr, Tcl_DStringValue(&append), 
					     Tcl_DStringLength(&append));
		} else {
		    joined = Tcl_DuplicateObj(pathPtr);
		    Tcl_AppendToObj(joined, Tcl_DStringValue(&append), 
				    Tcl_DStringLength(&append));
		}
	    } else {
		joined = Tcl_NewStringObj(Tcl_DStringValue(&append), 
					  Tcl_DStringLength(&append));
	    }
	    Tcl_IncrRefCount(joined);
	    Tcl_DStringFree(&append);
	    Tcl_FSMatchInDirectory(interp, Tcl_GetObjResult(interp), joined, 
				   NULL, types);
	    Tcl_DecrRefCount(joined);
	    return TCL_OK;
	}
    }
}

/*
 *---------------------------------------------------------------------------
 *
 * 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() {
    return (Tcl_StatBuf *) ckalloc(sizeof(Tcl_StatBuf));
}