2 * Copyright (c) 1989, 1991, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 #include <sys/param.h>
44 #endif /* STDC_HEADERS */
48 # ifdef HAVE_STRINGS_H
51 #endif /* HAVE_STRING_H */
52 #if defined(HAVE_MALLOC_H) && !defined(STDC_HEADERS)
54 #endif /* HAVE_MALLOC_H && !STDC_HEADERS */
57 #endif /* HAVE_UNISTD_H */
60 # define NAMLEN(dirent) strlen((dirent)->d_name)
62 # define dirent direct
63 # define NAMLEN(dirent) (dirent)->d_namlen
64 # ifdef HAVE_SYS_NDIR_H
65 # include <sys/ndir.h>
67 # ifdef HAVE_SYS_DIR_H
78 (dp->d_name[0] == '.' && (dp->d_name[1] == '\0' || \
79 (dp->d_name[1] == '.' && dp->d_name[2] == '\0')))
95 size_t ptsize, upsize;
100 * If no buffer specified by the user, allocate one as necessary.
101 * If a buffer is specified, the size has to be non-zero. The path
102 * is built from the end of the buffer backwards.
112 if ((pt = malloc(ptsize = 1024 - 4)) == NULL)
120 * Allocate bytes (1024 - malloc space) for the string of "../"'s.
121 * Should always be enough (it's 340 levels). If it's not, allocate
122 * as necessary. Special * case the first stat, it's ".", not "..".
124 if ((up = malloc(upsize = 1024 - 4)) == NULL)
131 /* Save root values, so know when to stop. */
137 errno = 0; /* XXX readdir has no error return. */
139 for (first = 1;; first = 0) {
140 /* Stat the current level. */
144 /* Save current node values. */
148 /* Check for reaching root. */
149 if (root_dev == dev && root_ino == ino) {
152 * It's unclear that it's a requirement to copy the
153 * path to the beginning of the buffer, but it's always
154 * been that way and stuff would probably break.
156 bcopy(bpt, pt, ept - bpt);
162 * Build pointer to the parent directory, allocating memory
163 * as necessary. Max length is 3 for "../", the largest
164 * possible component name, plus a trailing NULL.
166 if (bup + 3 + MAXNAMLEN + 1 >= eup) {
169 if ((nup = realloc(up, upsize *= 2)) == NULL)
179 /* Open and stat parent directory. */
180 if (!(dir = opendir(up)) || fstat(dirfd(dir), &s))
183 /* Add trailing slash for next directory. */
187 * If it's a mount point, have to stat each element because
188 * the inode number in the directory is for the entry in the
189 * parent directory, not the inode number of the mounted file.
192 if (s.st_dev == dev) {
194 if (!(dp = readdir(dir)))
196 if (dp->d_fileno == ino)
201 if (!(dp = readdir(dir)))
205 bcopy(dp->d_name, bup, NAMLEN(dp) + 1);
207 /* Save the first error for later. */
214 if (s.st_dev == dev && s.st_ino == ino)
219 * Check for length of the current name, preceding slash,
222 if (bpt - pt <= NAMLEN(dp) + (first ? 1 : 2)) {
232 if ((npt = realloc(pt, ptsize *= 2)) == NULL)
237 bcopy(bpt, ept - len, len);
243 bcopy(dp->d_name, bpt, NAMLEN(dp));
246 /* Truncate any file name. */
252 * If readdir set errno, use it, not any saved error; otherwise,
253 * didn't find the current directory in its parent directory, set
257 errno = save_errno ? save_errno : ENOENT;