source: MondoRescue/branches/2.2.2/mindi-busybox/libbb/simplify_path.c@ 1247

/* vi: set sw=4 ts=4: */
/*
 * bb_simplify_path implementation for busybox
 *
 * Copyright (C) 2001  Manuel Novoa III  <mjn3@codepoet.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

#include <stdlib.h>
#include "libbb.h"

char *bb_simplify_path(const char *path)
{
    char *s, *start, *p;

    if (path[0] == '/')
        start = bb_xstrdup(path);
    else {
        s = xgetcwd(NULL);
        start = concat_path_file(s, path);
        free(s);
    }
    p = s = start;

    do {
        if (*p == '/') {
            if (*s == '/') {    /* skip duplicate (or initial) slash */
                continue;
            } else if (*s == '.') {
                if (s[1] == '/' || s[1] == 0) { /* remove extra '.' */
                    continue;
                } else if ((s[1] == '.') && (s[2] == '/' || s[2] == 0)) {
                    ++s;
                    if (p > start) {
                        while (*--p != '/');    /* omit previous dir */
                    }
                    continue;
                }
            }
        }
        *++p = *s;
    } while (*++s);

    if ((p == start) || (*p != '/')) {  /* not a trailing slash */
        ++p;                    /* so keep last character */
    }
    *p = 0;

    return start;
}