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[binutils.git] / binutils / rename.c
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1 /* rename.c -- rename a file, preserving symlinks.
2 Copyright 1999, 2002, 2003 Free Software Foundation, Inc.
4 This file is part of GNU Binutils.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA
19 02110-1301, USA. */
21 #include "bfd.h"
22 #include "bucomm.h"
24 #include <sys/stat.h>
26 #ifdef HAVE_GOOD_UTIME_H
27 #include <utime.h>
28 #else /* ! HAVE_GOOD_UTIME_H */
29 #ifdef HAVE_UTIMES
30 #include <sys/time.h>
31 #endif /* HAVE_UTIMES */
32 #endif /* ! HAVE_GOOD_UTIME_H */
34 /* We need to open the file in binary modes on system where that makes
35 a difference. */
36 #ifndef O_BINARY
37 #define O_BINARY 0
38 #endif
40 #if ! defined (_WIN32) || defined (__CYGWIN32__)
41 static int simple_copy (const char *, const char *);
43 /* The number of bytes to copy at once. */
44 #define COPY_BUF 8192
46 /* Copy file FROM to file TO, performing no translations.
47 Return 0 if ok, -1 if error. */
49 static int
50 simple_copy (const char *from, const char *to)
52 int fromfd, tofd, nread;
53 int saved;
54 char buf[COPY_BUF];
56 fromfd = open (from, O_RDONLY | O_BINARY);
57 if (fromfd < 0)
58 return -1;
59 #ifdef O_CREAT
60 tofd = open (to, O_CREAT | O_WRONLY | O_TRUNC | O_BINARY, 0777);
61 #else
62 tofd = creat (to, 0777);
63 #endif
64 if (tofd < 0)
66 saved = errno;
67 close (fromfd);
68 errno = saved;
69 return -1;
71 while ((nread = read (fromfd, buf, sizeof buf)) > 0)
73 if (write (tofd, buf, nread) != nread)
75 saved = errno;
76 close (fromfd);
77 close (tofd);
78 errno = saved;
79 return -1;
82 saved = errno;
83 close (fromfd);
84 close (tofd);
85 if (nread < 0)
87 errno = saved;
88 return -1;
90 return 0;
92 #endif /* __CYGWIN32__ or not _WIN32 */
94 /* Set the times of the file DESTINATION to be the same as those in
95 STATBUF. */
97 void
98 set_times (const char *destination, const struct stat *statbuf)
100 int result;
103 #ifdef HAVE_GOOD_UTIME_H
104 struct utimbuf tb;
106 tb.actime = statbuf->st_atime;
107 tb.modtime = statbuf->st_mtime;
108 result = utime (destination, &tb);
109 #else /* ! HAVE_GOOD_UTIME_H */
110 #ifndef HAVE_UTIMES
111 long tb[2];
113 tb[0] = statbuf->st_atime;
114 tb[1] = statbuf->st_mtime;
115 result = utime (destination, tb);
116 #else /* HAVE_UTIMES */
117 struct timeval tv[2];
119 tv[0].tv_sec = statbuf->st_atime;
120 tv[0].tv_usec = 0;
121 tv[1].tv_sec = statbuf->st_mtime;
122 tv[1].tv_usec = 0;
123 result = utimes (destination, tv);
124 #endif /* HAVE_UTIMES */
125 #endif /* ! HAVE_GOOD_UTIME_H */
128 if (result != 0)
129 non_fatal (_("%s: cannot set time: %s"), destination, strerror (errno));
132 #ifndef S_ISLNK
133 #ifdef S_IFLNK
134 #define S_ISLNK(m) (((m) & S_IFMT) == S_IFLNK)
135 #else
136 #define S_ISLNK(m) 0
137 #define lstat stat
138 #endif
139 #endif
141 /* Rename FROM to TO, copying if TO is a link.
142 Return 0 if ok, -1 if error. */
145 smart_rename (const char *from, const char *to, int preserve_dates ATTRIBUTE_UNUSED)
147 bfd_boolean exists;
148 struct stat s;
149 int ret = 0;
151 exists = lstat (to, &s) == 0;
153 #if defined (_WIN32) && !defined (__CYGWIN32__)
154 /* Win32, unlike unix, will not erase `to' in `rename(from, to)' but
155 fail instead. Also, chown is not present. */
157 if (exists)
158 remove (to);
160 ret = rename (from, to);
161 if (ret != 0)
163 /* We have to clean up here. */
164 non_fatal (_("unable to rename '%s' reason: %s"), to, strerror (errno));
165 unlink (from);
167 #else
168 /* Use rename only if TO is not a symbolic link and has
169 only one hard link, and we have permission to write to it. */
170 if (! exists
171 || (!S_ISLNK (s.st_mode)
172 && S_ISREG (s.st_mode)
173 && (s.st_mode & S_IWUSR)
174 && s.st_nlink == 1)
177 ret = rename (from, to);
178 if (ret == 0)
180 if (exists)
182 /* Try to preserve the permission bits and ownership of
183 TO. First get the mode right except for the setuid
184 bit. Then change the ownership. Then fix the setuid
185 bit. We do the chmod before the chown because if the
186 chown succeeds, and we are a normal user, we won't be
187 able to do the chmod afterward. We don't bother to
188 fix the setuid bit first because that might introduce
189 a fleeting security problem, and because the chown
190 will clear the setuid bit anyhow. We only fix the
191 setuid bit if the chown succeeds, because we don't
192 want to introduce an unexpected setuid file owned by
193 the user running objcopy. */
194 chmod (to, s.st_mode & 0777);
195 if (chown (to, s.st_uid, s.st_gid) >= 0)
196 chmod (to, s.st_mode & 07777);
199 else
201 /* We have to clean up here. */
202 non_fatal (_("unable to rename '%s' reason: %s"), to, strerror (errno));
203 unlink (from);
206 else
208 ret = simple_copy (from, to);
209 if (ret != 0)
210 non_fatal (_("unable to copy file '%s' reason: %s"), to, strerror (errno));
212 if (preserve_dates)
213 set_times (to, &s);
214 unlink (from);
216 #endif /* _WIN32 && !__CYGWIN32__ */
218 return ret;