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	niro	532	/* 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			}