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#include "libbb.h"
10
11char* FAST_FUNC bb_simplify_abs_path_inplace(char *start)
12{
13	char *s, *p;
14
15	p = s = start;
16	do {
17		if (*p == '/') {
18			if (*s == '/') {	/* skip duplicate (or initial) slash */
19				continue;
20			}
21			if (*s == '.') {
22				if (s[1] == '/' || !s[1]) {	/* remove extra '.' */
23					continue;
24				}
25				if ((s[1] == '.') && (s[2] == '/' || !s[2])) {
26					++s;
27					if (p > start) {
28						while (*--p != '/')	/* omit previous dir */
29							continue;
30					}
31					continue;
32				}
33			}
34		}
35		*++p = *s;
36	} while (*++s);
37
38	if ((p == start) || (*p != '/')) {	/* not a trailing slash */
39		++p;					/* so keep last character */
40	}
41	*p = '\0';
42	return p;
43}
44
45char* FAST_FUNC bb_simplify_path(const char *path)
46{
47	char *s, *p;
48
49	if (path[0] == '/')
50		s = xstrdup(path);
51	else {
52		p = xrealloc_getcwd_or_warn(NULL);
53		s = concat_path_file(p, path);
54		free(p);
55	}
56
57	bb_simplify_abs_path_inplace(s);
58	return s;
59}
60