1/* rename.c -- rename a file, preserving symlinks. 2 Copyright 1999, 2002, 2003, 2007 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 "sysdep.h" 22#include "bfd.h" 23#include "bucomm.h" 24 25#include <sys/stat.h> 26 27#ifdef HAVE_GOOD_UTIME_H 28#include <utime.h> 29#else /* ! HAVE_GOOD_UTIME_H */ 30#ifdef HAVE_UTIMES 31#include <sys/time.h> 32#endif /* HAVE_UTIMES */ 33#endif /* ! HAVE_GOOD_UTIME_H */ 34 35/* We need to open the file in binary modes on system where that makes 36 a difference. */ 37#ifndef O_BINARY 38#define O_BINARY 0 39#endif 40 41#if ! defined (_WIN32) || defined (__CYGWIN32__) 42static int simple_copy (const char *, const char *); 43 44/* The number of bytes to copy at once. */ 45#define COPY_BUF 8192 46 47/* Copy file FROM to file TO, performing no translations. 48 Return 0 if ok, -1 if error. */ 49 50static int 51simple_copy (const char *from, const char *to) 52{ 53 int fromfd, tofd, nread; 54 int saved; 55 char buf[COPY_BUF]; 56 57 fromfd = open (from, O_RDONLY | O_BINARY); 58 if (fromfd < 0) 59 return -1; 60#ifdef O_CREAT 61 tofd = open (to, O_CREAT | O_WRONLY | O_TRUNC | O_BINARY, 0777); 62#else 63 tofd = creat (to, 0777); 64#endif 65 if (tofd < 0) 66 { 67 saved = errno; 68 close (fromfd); 69 errno = saved; 70 return -1; 71 } 72 while ((nread = read (fromfd, buf, sizeof buf)) > 0) 73 { 74 if (write (tofd, buf, nread) != nread) 75 { 76 saved = errno; 77 close (fromfd); 78 close (tofd); 79 errno = saved; 80 return -1; 81 } 82 } 83 saved = errno; 84 close (fromfd); 85 close (tofd); 86 if (nread < 0) 87 { 88 errno = saved; 89 return -1; 90 } 91 return 0; 92} 93#endif /* __CYGWIN32__ or not _WIN32 */ 94 95/* Set the times of the file DESTINATION to be the same as those in 96 STATBUF. */ 97 98void 99set_times (const char *destination, const struct stat *statbuf) 100{ 101 int result; 102 103 { 104#ifdef HAVE_GOOD_UTIME_H 105 struct utimbuf tb; 106 107 tb.actime = statbuf->st_atime; 108 tb.modtime = statbuf->st_mtime; 109 result = utime (destination, &tb); 110#else /* ! HAVE_GOOD_UTIME_H */ 111#ifndef HAVE_UTIMES 112 long tb[2]; 113 114 tb[0] = statbuf->st_atime; 115 tb[1] = statbuf->st_mtime; 116 result = utime (destination, tb); 117#else /* HAVE_UTIMES */ 118 struct timeval tv[2]; 119 120 tv[0].tv_sec = statbuf->st_atime; 121 tv[0].tv_usec = 0; 122 tv[1].tv_sec = statbuf->st_mtime; 123 tv[1].tv_usec = 0; 124 result = utimes (destination, tv); 125#endif /* HAVE_UTIMES */ 126#endif /* ! HAVE_GOOD_UTIME_H */ 127 } 128 129 if (result != 0) 130 non_fatal (_("%s: cannot set time: %s"), destination, strerror (errno)); 131} 132 133#ifndef S_ISLNK 134#ifdef S_IFLNK 135#define S_ISLNK(m) (((m) & S_IFMT) == S_IFLNK) 136#else 137#define S_ISLNK(m) 0 138#define lstat stat 139#endif 140#endif 141 142/* Rename FROM to TO, copying if TO is a link. 143 Return 0 if ok, -1 if error. */ 144 145int 146smart_rename (const char *from, const char *to, int preserve_dates ATTRIBUTE_UNUSED) 147{ 148 bfd_boolean exists; 149 struct stat s; 150 int ret = 0; 151 152 exists = lstat (to, &s) == 0; 153 154#if defined (_WIN32) && !defined (__CYGWIN32__) 155 /* Win32, unlike unix, will not erase `to' in `rename(from, to)' but 156 fail instead. Also, chown is not present. */ 157 158 if (exists) 159 remove (to); 160 161 ret = rename (from, to); 162 if (ret != 0) 163 { 164 /* We have to clean up here. */ 165 non_fatal (_("unable to rename '%s' reason: %s"), to, strerror (errno)); 166 unlink (from); 167 } 168#else 169 /* Use rename only if TO is not a symbolic link and has 170 only one hard link, and we have permission to write to it. */ 171 if (! exists 172 || (!S_ISLNK (s.st_mode) 173 && S_ISREG (s.st_mode) 174 && (s.st_mode & S_IWUSR) 175 && s.st_nlink == 1) 176 ) 177 { 178 ret = rename (from, to); 179 if (ret == 0) 180 { 181 if (exists) 182 { 183 /* Try to preserve the permission bits and ownership of 184 TO. First get the mode right except for the setuid 185 bit. Then change the ownership. Then fix the setuid 186 bit. We do the chmod before the chown because if the 187 chown succeeds, and we are a normal user, we won't be 188 able to do the chmod afterward. We don't bother to 189 fix the setuid bit first because that might introduce 190 a fleeting security problem, and because the chown 191 will clear the setuid bit anyhow. We only fix the 192 setuid bit if the chown succeeds, because we don't 193 want to introduce an unexpected setuid file owned by 194 the user running objcopy. */ 195 chmod (to, s.st_mode & 0777); 196 if (chown (to, s.st_uid, s.st_gid) >= 0) 197 chmod (to, s.st_mode & 07777); 198 } 199 } 200 else 201 { 202 /* We have to clean up here. */ 203 non_fatal (_("unable to rename '%s' reason: %s"), to, strerror (errno)); 204 unlink (from); 205 } 206 } 207 else 208 { 209 ret = simple_copy (from, to); 210 if (ret != 0) 211 non_fatal (_("unable to copy file '%s' reason: %s"), to, strerror (errno)); 212 213 if (preserve_dates) 214 set_times (to, &s); 215 unlink (from); 216 } 217#endif /* _WIN32 && !__CYGWIN32__ */ 218 219 return ret; 220} 221