source: MondoRescue/branches/2.2.5/mindi-busybox/libbb/simplify_path.c@ 1765

/* vi: set sw=4 ts=4: */
/*
 * bb_simplify_path implementation for busybox
 *
 * Copyright (C) 2001  Manuel Novoa III  <mjn3@codepoet.org>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

#include "libbb.h"

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

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

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

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

    return start;
}