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 source tree.
8  */
9 #include "libbb.h"
10 
bb_simplify_abs_path_inplace(char * start)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 
bb_simplify_path(const char * path)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 }
60