1 /* Return the canonical absolute name of a given file.
2 Copyright (C) 1996-2005 Free Software Foundation, Inc.
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2, or (at your option)
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; see the file COPYING.
16 If not, write to the Free Software Foundation,
17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
23 #include "canonicalize.h"
31 #if defined STDC_HEADERS || defined HAVE_STRING_H
38 # include <sys/param.h>
50 #include "cycle-check.h"
51 #include "filenamecat.h"
52 #include "stat-macros.h"
57 # define __set_errno(Val) errno = (Val)
61 #include "xreadlink.h"
63 #if !HAVE_CANONICALIZE_FILE_NAME
64 /* Return the canonical absolute name of file NAME. A canonical name
65 does not contain any `.', `..' components nor any repeated file name
66 separators ('/') or symlinks. All components must exist.
67 The result is malloc'd. */
70 canonicalize_file_name (const char *name)
74 char *resolved, *extra_buf = NULL;
90 /* All known hosts with resolvepath (e.g. Solaris 7) don't turn
91 relative names into absolute ones, so prepend the working
92 directory if the file name is not absolute. */
97 if (!(wd = xgetcwd ()))
100 extra_buf = file_name_concat (wd, name, NULL);
105 resolved_size = strlen (name);
108 resolved_size = 2 * resolved_size + 1;
109 resolved = xmalloc (resolved_size);
110 resolved_len = resolvepath (name, resolved, resolved_size);
111 if (resolved_len < 0)
117 if (resolved_len < resolved_size)
124 /* NUL-terminate the resulting name. */
125 resolved[resolved_len] = '\0';
131 return canonicalize_filename_mode (name, CAN_EXISTING);
133 # endif /* !HAVE_RESOLVEPATH */
135 #endif /* !HAVE_CANONICALIZE_FILE_NAME */
137 /* Return the canonical absolute name of file NAME. A canonical name
138 does not contain any `.', `..' components nor any repeated file name
139 separators ('/') or symlinks. Whether components must exist
140 or not depends on canonicalize mode. The result is malloc'd. */
143 canonicalize_filename_mode (const char *name, canonicalize_mode_t can_mode)
145 char *rname, *dest, *extra_buf = NULL;
148 char const *rname_limit;
149 size_t extra_len = 0;
150 struct cycle_check_state cycle_state;
154 __set_errno (EINVAL);
160 __set_errno (ENOENT);
169 dest = strchr (rname, '\0');
170 if (dest - rname < PATH_MAX)
172 char *p = xrealloc (rname, PATH_MAX);
173 dest = p + (dest - rname);
175 rname_limit = rname + PATH_MAX;
184 rname = xmalloc (PATH_MAX);
185 rname_limit = rname + PATH_MAX;
190 cycle_check_init (&cycle_state);
191 for (start = end = name; *start; start = end)
193 /* Skip sequence of multiple file name separators. */
194 while (*start == '/')
197 /* Find end of component. */
198 for (end = start; *end && *end != '/'; ++end)
201 if (end - start == 0)
203 else if (end - start == 1 && start[0] == '.')
205 else if (end - start == 2 && start[0] == '.' && start[1] == '.')
207 /* Back up to previous component, ignore if at root already. */
208 if (dest > rname + 1)
209 while ((--dest)[-1] != '/');
218 if (dest + (end - start) >= rname_limit)
220 ptrdiff_t dest_offset = dest - rname;
221 size_t new_size = rname_limit - rname;
223 if (end - start + 1 > PATH_MAX)
224 new_size += end - start + 1;
226 new_size += PATH_MAX;
227 rname = xrealloc (rname, new_size);
228 rname_limit = rname + new_size;
230 dest = rname + dest_offset;
233 dest = memcpy (dest, start, end - start);
237 if (lstat (rname, &st) != 0)
239 if (can_mode == CAN_EXISTING)
241 if (can_mode == CAN_ALL_BUT_LAST && *end)
246 if (S_ISLNK (st.st_mode))
251 if (cycle_check (&cycle_state, &st))
254 if (can_mode == CAN_MISSING)
260 buf = xreadlink (rname, st.st_size);
263 if (can_mode == CAN_MISSING)
275 ((n + len + 1) > PATH_MAX) ? (n + len + 1) : PATH_MAX;
276 extra_buf = xmalloc (extra_len);
278 else if ((n + len + 1) > extra_len)
280 extra_len = n + len + 1;
281 extra_buf = xrealloc (extra_buf, extra_len);
284 /* Careful here, end may be a pointer into extra_buf... */
285 memmove (&extra_buf[n], end, len + 1);
286 name = end = memcpy (extra_buf, buf, n);
289 dest = rname + 1; /* It's an absolute symlink */
291 /* Back up to previous component, ignore if at root already: */
292 if (dest > rname + 1)
293 while ((--dest)[-1] != '/');
299 if (!S_ISDIR (st.st_mode) && *end && (can_mode != CAN_MISSING))
307 if (dest > rname + 1 && dest[-1] == '/')