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authorcvs2svn <admin@example.com>1998-10-19 21:47:13 +0000
committercvs2svn <admin@example.com>1998-10-19 21:47:13 +0000
commitf954a53a9a7dced3fb4c80b1e8dd267981ae025d (patch)
treec667406046ddb1efca5ed4316b02e43494241660 /src/lib/libc/stdlib/realpath.c
parent536c76cbb863bab152f19842ab88772c01e922c7 (diff)
downloadopenbsd-OPENBSD_2_4.tar.gz
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This commit was manufactured by cvs2git to create branch 'OPENBSD_2_4'.OPENBSD_2_4
Diffstat (limited to 'src/lib/libc/stdlib/realpath.c')
-rw-r--r--src/lib/libc/stdlib/realpath.c163
1 files changed, 163 insertions, 0 deletions
diff --git a/src/lib/libc/stdlib/realpath.c b/src/lib/libc/stdlib/realpath.c
new file mode 100644
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+++ b/src/lib/libc/stdlib/realpath.c
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1/*
2 * Copyright (c) 1994
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Jan-Simon Pendry.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#if defined(LIBC_SCCS) && !defined(lint)
38static char *rcsid = "$OpenBSD: realpath.c,v 1.4 1998/05/18 09:55:19 deraadt Exp $";
39#endif /* LIBC_SCCS and not lint */
40
41#include <sys/param.h>
42#include <sys/stat.h>
43
44#include <errno.h>
45#include <fcntl.h>
46#include <stdlib.h>
47#include <string.h>
48#include <unistd.h>
49
50/*
51 * char *realpath(const char *path, char resolved_path[MAXPATHLEN]);
52 *
53 * Find the real name of path, by removing all ".", ".." and symlink
54 * components. Returns (resolved) on success, or (NULL) on failure,
55 * in which case the path which caused trouble is left in (resolved).
56 */
57char *
58realpath(path, resolved)
59 const char *path;
60 char *resolved;
61{
62 struct stat sb;
63 int fd, n, rootd, serrno;
64 char *p, *q, wbuf[MAXPATHLEN];
65 int symlinks = 0;
66
67 /* Save the starting point. */
68 if ((fd = open(".", O_RDONLY)) < 0) {
69 (void)strcpy(resolved, ".");
70 return (NULL);
71 }
72
73 /*
74 * Find the dirname and basename from the path to be resolved.
75 * Change directory to the dirname component.
76 * lstat the basename part.
77 * if it is a symlink, read in the value and loop.
78 * if it is a directory, then change to that directory.
79 * get the current directory name and append the basename.
80 */
81 (void)strncpy(resolved, path, MAXPATHLEN - 1);
82 resolved[MAXPATHLEN - 1] = '\0';
83loop:
84 q = strrchr(resolved, '/');
85 if (q != NULL) {
86 p = q + 1;
87 if (q == resolved)
88 q = "/";
89 else {
90 do {
91 --q;
92 } while (q > resolved && *q == '/');
93 q[1] = '\0';
94 q = resolved;
95 }
96 if (chdir(q) < 0)
97 goto err1;
98 } else
99 p = resolved;
100
101 /* Deal with the last component. */
102 if (lstat(p, &sb) == 0) {
103 if (S_ISLNK(sb.st_mode)) {
104 if (++symlinks > MAXSYMLINKS) {
105 errno = ELOOP;
106 goto err1;
107 }
108 n = readlink(p, resolved, MAXPATHLEN-1);
109 if (n < 0)
110 goto err1;
111 resolved[n] = '\0';
112 goto loop;
113 }
114 if (S_ISDIR(sb.st_mode)) {
115 if (chdir(p) < 0)
116 goto err1;
117 p = "";
118 }
119 }
120
121 /*
122 * Save the last component name and get the full pathname of
123 * the current directory.
124 */
125 (void)strcpy(wbuf, p);
126 if (getcwd(resolved, MAXPATHLEN) == 0)
127 goto err1;
128
129 /*
130 * Join the two strings together, ensuring that the right thing
131 * happens if the last component is empty, or the dirname is root.
132 */
133 if (resolved[0] == '/' && resolved[1] == '\0')
134 rootd = 1;
135 else
136 rootd = 0;
137
138 if (*wbuf) {
139 if (strlen(resolved) + strlen(wbuf) + rootd + 1 > MAXPATHLEN) {
140 errno = ENAMETOOLONG;
141 goto err1;
142 }
143 if (rootd == 0)
144 (void)strcat(resolved, "/");
145 (void)strcat(resolved, wbuf);
146 }
147
148 /* Go back to where we came from. */
149 if (fchdir(fd) < 0) {
150 serrno = errno;
151 goto err2;
152 }
153
154 /* It's okay if the close fails, what's an fd more or less? */
155 (void)close(fd);
156 return (resolved);
157
158err1: serrno = errno;
159 (void)fchdir(fd);
160err2: (void)close(fd);
161 errno = serrno;
162 return (NULL);
163}