1 /* Set file access and modification times.
3 Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 Free Software
6 This program is free software: you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published by the
8 Free Software Foundation; either version 3 of the License, or any
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, see <http://www.gnu.org/licenses/>. */
19 /* Written by Paul Eggert. */
21 /* derived from a function in touch.c */
37 /* Some systems (even some that do have <utime.h>) don't declare this
38 structure anywhere. */
39 #ifndef HAVE_STRUCT_UTIMBUF
47 /* Some systems don't have ENOSYS. */
50 # define ENOSYS ENOTSUP
52 /* Some systems don't have ENOTSUP either. */
53 # define ENOSYS EINVAL
58 # if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8)
59 # define __attribute__(x)
63 #ifndef ATTRIBUTE_UNUSED
64 # define ATTRIBUTE_UNUSED __attribute__ ((__unused__))
67 /* Set the access and modification time stamps of FD (a.k.a. FILE) to be
68 TIMESPEC[0] and TIMESPEC[1], respectively.
69 FD must be either negative -- in which case it is ignored --
70 or a file descriptor that is open on FILE.
71 If FD is nonnegative, then FILE can be NULL, which means
72 use just futimes (or equivalent) instead of utimes (or equivalent),
73 and fail if on an old system without futimes (or equivalent).
74 If TIMESPEC is null, set the time stamps to the current time.
75 If the file is a symlink and IS_SYMLINK is set, then the
76 time stamps of the symlink itself will be updated if
77 possible, (but if not supported by the operating system
78 then no change will occur).
79 Return 0 on success, -1 (setting errno) on failure. */
82 gl_futimens (int fd ATTRIBUTE_UNUSED,
83 char const *file, struct timespec const timespec[2],
86 /* Some Linux-based NFS clients are buggy, and mishandle time stamps
87 of files in NFS file systems in some cases. We have no
88 configure-time test for this, but please see
89 <http://bugs.gentoo.org/show_bug.cgi?id=132673> for references to
90 some of the problems with Linux 2.6.16. If this affects you,
91 compile with -DHAVE_BUGGY_NFS_TIME_STAMPS; this is reported to
92 help in some cases, albeit at a cost in performance. But you
93 really should upgrade your kernel to a fixed version, since the
94 problem affects many applications. */
96 #if HAVE_BUGGY_NFS_TIME_STAMPS
103 /* POSIX 200x added two interfaces to set file timestamps with
104 nanosecond resolution. We provide a fallback for ENOSYS (for
105 example, compiling against Linux 2.6.25 kernel headers and glibc
106 2.7, but running on Linux 2.6.18 kernel). */
110 int flags = is_symlink ? AT_SYMLINK_NOFOLLOW : 0;
111 int result = utimensat (AT_FDCWD, file, timespec, flags);
113 /* Work around what might be a kernel bug:
114 http://bugzilla.redhat.com/442352
115 http://bugzilla.redhat.com/449910
116 It appears that utimensat can mistakenly return 280 rather
117 than -1 upon failure.
118 FIXME: remove in 2010 or whenever the offending kernels
119 are no longer in common use. */
124 if (result == 0 || errno != ENOSYS)
129 /* Without utimensat we have no way to update a symlink rather than
130 * the target, so just return immediately. */
136 int result = futimens (fd, timespec);
138 /* Work around the same bug as above. */
142 if (result == 0 || errno != ENOSYS)
147 /* The platform lacks an interface to set file timestamps with
148 nanosecond resolution, so do the best we can, discarding any
149 fractional part of the timestamp. */
151 #if HAVE_FUTIMESAT || HAVE_WORKING_UTIMES
152 struct timeval timeval[2];
153 struct timeval const *t;
156 timeval[0].tv_sec = timespec[0].tv_sec;
157 timeval[0].tv_usec = timespec[0].tv_nsec / 1000;
158 timeval[1].tv_sec = timespec[1].tv_sec;
159 timeval[1].tv_usec = timespec[1].tv_nsec / 1000;
168 return futimesat (AT_FDCWD, file, t);
173 /* If futimesat or futimes fails here, don't try to speed things
174 up by returning right away. glibc can incorrectly fail with
175 errno == ENOENT if /proc isn't mounted. Also, Mandrake 10.0
176 in high security mode doesn't allow ordinary users to read
177 /proc/self, so glibc incorrectly fails with errno == EACCES.
178 If errno == EIO, EPERM, or EROFS, it's probably safe to fail
179 right away, but these cases are rare enough that they're not
180 worth optimizing, and who knows what other messed-up systems
181 are out there? So play it safe and fall back on the code
184 if (futimesat (fd, NULL, t) == 0)
187 if (futimes (fd, t) == 0)
191 #endif /* HAVE_FUTIMESAT || HAVE_WORKING_UTIMES */
195 #if ! (HAVE_FUTIMESAT || (HAVE_WORKING_UTIMES && HAVE_FUTIMES))
199 /* Prefer EBADF to ENOSYS if both error numbers apply. */
203 int dup_errno = errno;
206 errno = (fd2 < 0 && dup_errno == EBADF ? EBADF : ENOSYS);
212 #if HAVE_WORKING_UTIMES
213 return utimes (file, t);
216 struct utimbuf utimbuf;
217 struct utimbuf const *ut;
220 utimbuf.actime = timespec[0].tv_sec;
221 utimbuf.modtime = timespec[1].tv_sec;
227 return utime (file, ut);
229 #endif /* !HAVE_WORKING_UTIMES */
233 /* Set the access and modification time stamps of FILE to be
234 TIMESPEC[0] and TIMESPEC[1], respectively.
235 If the file is a symlink and is_symlink is set, then the
236 time stamps of the symlink itself will be updated if
237 possible, (but if not supported by the operating system
238 then no change will occur). */
240 utimens (char const *file, struct timespec const timespec[2], int is_symlink)
242 return gl_futimens (-1, file, timespec, is_symlink);