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* FAST_FUNC bb_simplify_abs_path_inplace(char *start)
{
	char *s, *p;

	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 p;
}

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

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

	bb_simplify_abs_path_inplace(s);
	return s;
}
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
11	char* 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
45	char* 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	}