busybox/libbb/simplify_path.c

/* 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 = 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;
}
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
12	char 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 = xgetcwd(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	} else if (*s == '.') {
30	if (s[1] == '/' \|\| s[1] == 0) { /* remove extra '.' */
31	continue;
32	} else if ((s[1] == '.') && (s[2] == '/' \|\| s[2] == 0)) {
33	++s;
34	if (p > start) {
35	while (--p != '/'); / omit previous dir */
36	}
37	continue;
38	}
39	}
40	}
41	++p = s;
42	} while (*++s);
43
44	if ((p == start) \|\| (p != '/')) { / not a trailing slash */
45	++p; /* so keep last character */
46	}
47	*p = 0;
48
49	return start;
50	}