1 /* rename.c -- rename a file, preserving symlinks.
2 Copyright 1999, 2002, 2003 Free Software Foundation, Inc.
3
4 This file is part of GNU Binutils.
5
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.
10
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.
15
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. */
20
21 #include "bfd.h"
22 #include "bucomm.h"
23
24 #include <sys/stat.h>
25
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 */
33
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
39
40 #if ! defined (_WIN32) || defined (__CYGWIN32__)
41 static int simple_copy (const char *, const char *);
42
43 /* The number of bytes to copy at once. */
44 #define COPY_BUF 8192
45
46 /* Copy file FROM to file TO, performing no translations.
47 Return 0 if ok, -1 if error. */
48
49 static int
simple_copy(const char * from,const char * to)50 simple_copy (const char *from, const char *to)
51 {
52 int fromfd, tofd, nread;
53 int saved;
54 char buf[COPY_BUF];
55
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)
65 {
66 saved = errno;
67 close (fromfd);
68 errno = saved;
69 return -1;
70 }
71 while ((nread = read (fromfd, buf, sizeof buf)) > 0)
72 {
73 if (write (tofd, buf, nread) != nread)
74 {
75 saved = errno;
76 close (fromfd);
77 close (tofd);
78 errno = saved;
79 return -1;
80 }
81 }
82 saved = errno;
83 close (fromfd);
84 close (tofd);
85 if (nread < 0)
86 {
87 errno = saved;
88 return -1;
89 }
90 return 0;
91 }
92 #endif /* __CYGWIN32__ or not _WIN32 */
93
94 /* Set the times of the file DESTINATION to be the same as those in
95 STATBUF. */
96
97 void
set_times(const char * destination,const struct stat * statbuf)98 set_times (const char *destination, const struct stat *statbuf)
99 {
100 int result;
101
102 {
103 #ifdef HAVE_GOOD_UTIME_H
104 struct utimbuf tb;
105
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];
112
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];
118
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 */
126 }
127
128 if (result != 0)
129 non_fatal (_("%s: cannot set time: %s"), destination, strerror (errno));
130 }
131
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
140
141 /* Rename FROM to TO, copying if TO is a link.
142 Return 0 if ok, -1 if error. */
143
144 int
smart_rename(const char * from,const char * to,int preserve_dates ATTRIBUTE_UNUSED)145 smart_rename (const char *from, const char *to, int preserve_dates ATTRIBUTE_UNUSED)
146 {
147 bfd_boolean exists;
148 struct stat s;
149 int ret = 0;
150
151 exists = lstat (to, &s) == 0;
152
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. */
156
157 if (exists)
158 remove (to);
159
160 ret = rename (from, to);
161 if (ret != 0)
162 {
163 /* We have to clean up here. */
164 non_fatal (_("unable to rename '%s' reason: %s"), to, strerror (errno));
165 unlink (from);
166 }
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)
175 )
176 {
177 ret = rename (from, to);
178 if (ret == 0)
179 {
180 if (exists)
181 {
182 /* Try to preserve the permission bits of TO. Don't
183 * restore special bits. */
184 chmod (to, s.st_mode & 0777);
185 }
186 }
187 else
188 {
189 /* We have to clean up here. */
190 non_fatal (_("unable to rename '%s' reason: %s"), to, strerror (errno));
191 unlink (from);
192 }
193 }
194 else
195 {
196 ret = simple_copy (from, to);
197 if (ret != 0)
198 non_fatal (_("unable to copy file '%s' reason: %s"), to, strerror (errno));
199
200 if (preserve_dates)
201 set_times (to, &s);
202 unlink (from);
203 }
204 #endif /* _WIN32 && !__CYGWIN32__ */
205
206 return ret;
207 }
208