tclglob.c

CMX990 demonstration board (DE9901)

/* 
 * tclGlob.c --
 *
 *	This file provides procedures and commands for file name
 *	manipulation, such as tilde expansion and globbing.
 *
 * Copyright 1990-1991 Regents of the University of California
 * Permission to use, copy, modify, and distribute this
 * software and its documentation for any purpose and without
 * fee is hereby granted, provided that the above copyright
 * notice appear in all copies.  The University of California
 * makes no representations about the suitability of this
 * software for any purpose.  It is provided "as is" without
 * express or implied warranty.
 *
 * $Id: tclGlob.c,v 1.1.1.1 2001/04/29 20:34:49 karll Exp $
 */

#include "tclInt.h"
#include "tclEcos.h"
#include <pwd.h>

/*
 * The structure below is used to keep track of a globbing result
 * being built up (i.e. a partial list of file names).  The list
 * grows dynamically to be as big as needed.
 */

typedef struct {
    char *result;		/* Pointer to result area. */
    int totalSpace;		/* Total number of characters allocated
				 * for result. */
    int spaceUsed;		/* Number of characters currently in use
				 * to hold the partial result (not including
				 * the terminating NULL). */
    int dynamic;		/* 0 means result is static space, 1 means
				 * it's dynamic. */
} GlobResult;

/*
 * Declarations for procedures local to this file:
 */

static void		AppendResult _ANSI_ARGS_((Tcl_Interp *interp,
			    char *dir, char *separator, char *name,
			    int nameLength));
static int		DoGlob _ANSI_ARGS_((Tcl_Interp *interp, char *dir,
			    char *rem));

/*
 *----------------------------------------------------------------------
 *
 * AppendResult --
 *
 *	Given two parts of a file name (directory and element within
 *	directory), concatenate the two together and append them to
 *	the result building up in interp.
 *
 * Results:
 *	There is no return value.
 *
 * Side effects:
 *	Interp->result gets extended.
 *
 *----------------------------------------------------------------------
 */

static void
AppendResult(interp, dir, separator, name, nameLength)
    Tcl_Interp *interp;		/* Interpreter whose result should be
				 * appended to. */
    char *dir;			/* Name of directory, without trailing
				 * slash except for root directory. */
    char *separator;		/* Separator string so use between dir and
				 * name:  either "/" or "" depending on dir. */
    char *name;			/* Name of file withing directory (NOT
				 * necessarily null-terminated!). */
    int nameLength;		/* Number of characters in name. */
{
    int dirFlags, nameFlags;
    char *p, saved;

    /*
     * Next, see if we can put together a valid list element from dir
     * and name by calling Tcl_AppendResult.
     */

    if (*dir == 0) {
	dirFlags = 0;
    } else {
	Tcl_ScanElement(dir, &dirFlags);
    }
    saved = name[nameLength];
    name[nameLength] = 0;
    Tcl_ScanElement(name, &nameFlags);
    if ((dirFlags == 0) && (nameFlags == 0)) {
	if (*interp->result != 0) {
	    Tcl_AppendResult(interp, " ", dir, separator, name, (char *) NULL);
	} else {
	    Tcl_AppendResult(interp, dir, separator, name, (char *) NULL);
	}
	name[nameLength] = saved;
	return;
    }

    /*
     * This name has weird characters in it, so we have to convert it to
     * a list element.  To do that, we have to merge the characters
     * into a single name.  To do that, malloc a buffer to hold everything.
     */

    p = (char *) ckalloc((unsigned) (strlen(dir) + strlen(separator)
	    + nameLength + 1));
    sprintf(p, "%s%s%s", dir, separator, name);
    name[nameLength] = saved;
    Tcl_AppendElement(interp, p, 0);
    ckfree(p);
}

/*
 *----------------------------------------------------------------------
 *
 * 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.
 *
 * Results:
 *	The return value is a standard Tcl result indicating whether
 *	an error occurred in globbing.  After a normal return the
 *	result in interp will be set to hold all of the file names
 *	given by the dir and rem arguments.  After an error the
 *	result in interp will hold an error message.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int DoGlob(Tcl_Interp *interp, char *dir, char *rem)
  //    Tcl_Interp *interp;		/* Interpreter to use for error
  //					 * reporting (e.g. unmatched brace). */
  //    char *dir;			/* Name of a directory at which to
  //					 * start glob expansion.  This name
  //					 * is fixed: it doesn't contain any
  //					 * globbing chars. */
  //    char *rem;			/* Path to glob-expand. */
{
    /*
     * When this procedure is entered, the name to be globbed may
     * already have been partly expanded by ancestor invocations of
     * DoGlob.  The part that's already been expanded is in "dir"
     * (this may initially be empty), and the part still to expand
     * is in "rem".  This procedure expands "rem" one level, making
     * recursive calls to itself if there's still more stuff left
     * in the remainder.
     */

    register char *p;
    register char c;
    char *openBrace, *closeBrace;
    int gotSpecial, result;
    char *separator;

    /*
     * Figure out whether we'll need to add a slash between the directory
     * name and file names within the directory when concatenating them
     * together.
     */

    if ((dir[0] == 0) || ((dir[0] == '/') && (dir[1] == 0))) {
	separator = "";
    } else {
	separator = "/";
    }

    /*
     * When generating information for the next lower call,
     * use static areas if the name is short, and malloc if the name
     * is longer.
     */

#define STATIC_SIZE 200

    /*
     * First, find the end of the next element in rem, checking
     * along the way for special globbing characters.
     */

    gotSpecial = 0;
    openBrace = closeBrace = NULL;
    for (p = rem; ; p++) {
	c = *p;
	if ((c == '\0') || (c == '/')) {
	    break;
	}
	if ((c == '{') && (openBrace == NULL)) {
	    openBrace = p;
	}
	if ((c == '}') && (closeBrace == NULL)) {
	    closeBrace = p;
	}
	if ((c == '*') || (c == '[') || (c == '\\') || (c == '?')) {
	    gotSpecial = 1;
	}
    }

    /*
     * If there is an open brace in the argument, then make a recursive
     * call for each element between the braces.  In this case, the
     * recursive call to DoGlob uses the same "dir" that we got.
     * If there are several brace-pairs in a single name, we just handle
     * one here, and the others will be handled in recursive calls.
     */

    if (openBrace != NULL) {
	int remLength, l1, l2;
	char static1[STATIC_SIZE];
	char *element, *newRem;

	if (closeBrace == NULL) {
	    Tcl_ResetResult(interp);
	    interp->result = "unmatched open-brace in file name";
	    return TCL_ERROR;
	}
	remLength = strlen(rem) + 1;
	if (remLength <= STATIC_SIZE) {
	    newRem = static1;
	} else {
	    newRem = (char *) ckalloc((unsigned) remLength);
	}
	l1 = openBrace-rem;
	strncpy(newRem, rem, l1);
	p = openBrace;
	for (p = openBrace; *p != '}'; ) {
	    element = p+1;
	    for (p = element; ((*p != '}') && (*p != ',')); p++) {
		/* Empty loop body:  just find end of this element. */
	    }
	    l2 = p - element;
	    strncpy(newRem+l1, element, l2);
	    strcpy(newRem+l1+l2, closeBrace+1);
	    if (DoGlob(interp, dir, newRem) != TCL_OK) {
		return TCL_ERROR;
	    }
	}
	if (remLength > STATIC_SIZE) {
	    ckfree(newRem);
	}
	return TCL_OK;
    }

    /*
     * If there were any pattern-matching characters, then scan through
     * the directory to find all the matching names.
     */

    if (gotSpecial) {
	DIR *d;
	struct dirent *entryPtr;
	int l1, l2;
	char *pattern, *newDir, *dirName;
	char static1[STATIC_SIZE], static2[STATIC_SIZE];
	struct stat statBuf;

	/*
	 * Be careful not to do any actual file system operations on a
	 * directory named "";  instead, use ".".  This is needed because
	 * some versions of UNIX don't treat "" like "." automatically.
	 */

	if (*dir == '\0') {
	    dirName = ".";
	} else {
	    dirName = dir;
	}
	if ((stat(dirName, &statBuf) != 0) || !S_ISDIR(statBuf.st_mode)) {
	    return TCL_OK;
	}
	d = opendir(dirName);