1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
|
/*
* Copyright (c) 1994
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Jan-Simon Pendry.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/* $XFree86$ */
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)realpath.c 8.1 (Berkeley) 2/16/94";
#endif /* LIBC_SCCS and not lint */
#include <sys/param.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#ifndef LISP
#include "xedit.h"
#endif
#if defined(__Lynx__)
#define NO_FCHDIR
#endif
#if defined(ISC)
#ifndef MAXPATHLEN
#define MAXPATHLEN 1024
#endif
#endif
#ifndef MAXSYMLINKS
#define MAXSYMLINKS 256
#endif
/*
* char *realpath(const char *path, char resolved_path[MAXPATHLEN]);
*
* Find the real name of path, by removing all ".", ".." and symlink
* components. Returns (resolved) on success, or (NULL) on failure,
* in which case the path which caused trouble is left in (resolved).
*/
char *
realpath(path, resolved)
const char *path;
char *resolved;
{
struct stat sb;
#ifdef NO_FCHDIR
char start[MAXPATHLEN];
#else
int fd;
#endif
int n, rootd, serrno;
char *p, *q, wbuf[MAXPATHLEN];
int symlinks = 0;
/* Save the starting point. */
#ifdef NO_FCHDIR
if (getcwd(start, MAXPATHLEN) == NULL) {
(void)strcpy(resolved, ".");
return (NULL);
}
#else
if ((fd = open(".", O_RDONLY)) < 0) {
(void)strcpy(resolved, ".");
return (NULL);
}
#endif
/*
* Find the dirname and basename from the path to be resolved.
* Change directory to the dirname component.
* lstat the basename part.
* if it is a symlink, read in the value and loop.
* if it is a directory, then change to that directory.
* get the current directory name and append the basename.
*/
(void)strncpy(resolved, path, MAXPATHLEN - 1);
resolved[MAXPATHLEN - 1] = '\0';
loop:
q = strrchr(resolved, '/');
if (q != NULL) {
p = q + 1;
if (q == resolved)
q = "/";
else {
do {
--q;
} while (q > resolved && *q == '/');
q[1] = '\0';
q = resolved;
}
if (chdir(q) < 0)
goto err1;
} else
p = resolved;
/* Deal with the last component. */
if (*p != '\0' && lstat(p, &sb) == 0) {
if (S_ISLNK(sb.st_mode)) {
if (++symlinks > MAXSYMLINKS) {
errno = ELOOP;
goto err1;
}
n = readlink(p, resolved, MAXPATHLEN);
if (n < 0)
goto err1;
resolved[n] = '\0';
goto loop;
}
if (S_ISDIR(sb.st_mode)) {
if (chdir(p) < 0)
goto err1;
p = "";
}
}
/*
* Save the last component name and get the full pathname of
* the current directory.
*/
(void)strcpy(wbuf, p);
if (getcwd(resolved, MAXPATHLEN) == 0)
goto err1;
/*
* Join the two strings together, ensuring that the right thing
* happens if the last component is empty, or the dirname is root.
*/
if (resolved[0] == '/' && resolved[1] == '\0')
rootd = 1;
else
rootd = 0;
if (*wbuf) {
if (strlen(resolved) + strlen(wbuf) + rootd + 1 > MAXPATHLEN) {
errno = ENAMETOOLONG;
goto err1;
}
if (rootd == 0)
(void)strcat(resolved, "/");
(void)strcat(resolved, wbuf);
}
/* Go back to where we came from. */
#ifdef NO_FCHDIR
if (chdir(start) < 0)
#else
if (fchdir(fd) < 0)
#endif
{
serrno = errno;
goto err2;
}
/* It's okay if the close fails, what's an fd more or less? */
#ifndef NO_FCHDIR
(void)close(fd);
#endif
return (resolved);
err1: serrno = errno;
#ifdef NO_FCHDIR
(void)chdir(start);
#else
(void)fchdir(fd);
#endif
err2:
#ifndef NO_FCHDIR
(void)close(fd);
#endif
errno = serrno;
return (NULL);
}
|
