1/* vi: set sw=4 ts=4: */
2/*
3 * bb_simplify_path implementation for busybox
4 *
5 * Copyright (C) 2001  Manuel Novoa III  <mjn3@codepoet.org>
6 *
7 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
8 */
9
10#include "libbb.h"
11
12char *bb_simplify_path(const char *path)
13{
14	char *s, *start, *p;
15
16	if (path[0] == '/')
17		start = xstrdup(path);
18	else {
19		s = xrealloc_getcwd_or_warn(NULL);
20		start = concat_path_file(s, path);
21		free(s);
22	}
23	p = s = start;
24
25	do {
26		if (*p == '/') {
27			if (*s == '/') {	/* skip duplicate (or initial) slash */
28				continue;
29			}
30			if (*s == '.') {
31				if (s[1] == '/' || !s[1]) {	/* remove extra '.' */
32					continue;
33				}
34				if ((s[1] == '.') && (s[2] == '/' || !s[2])) {
35					++s;
36					if (p > start) {
37						while (*--p != '/')	/* omit previous dir */
38							continue;
39					}
40					continue;
41				}
42			}
43		}
44		*++p = *s;
45	} while (*++s);
46
47	if ((p == start) || (*p != '/')) {	/* not a trailing slash */
48		++p;					/* so keep last character */
49	}
50	*p = 0;
51
52	return start;
53}
54