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NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | STANDARDS | HISTORY | NOTES | SEE ALSO | COLOPHON |
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utime(2) System Calls Manual utime(2)
utime, utimes - change file last access and modification times
Standard C library (libc, -lc)
#include <utime.h>
int utime(const char *filename,
const struct utimbuf *_Nullable times);
#include <sys/time.h>
int utimes(const char *filename,
const struct timeval times[_Nullable 2]);
Note: modern applications may prefer to use the interfaces
described in utimensat(2).
The utime() system call changes the access and modification times
of the inode specified by filename to the actime and modtime
fields of times respectively. The status change time (ctime) will
be set to the current time, even if the other time stamps don't
actually change.
If times is NULL, then the access and modification times of the
file are set to the current time.
Changing timestamps is permitted when: either the process has
appropriate privileges, or the effective user ID equals the user
ID of the file, or times is NULL and the process has write
permission for the file.
The utimbuf structure is:
struct utimbuf {
time_t actime; /* access time */
time_t modtime; /* modification time */
};
The utime() system call allows specification of timestamps with a
resolution of 1 second.
The utimes() system call is similar, but the times argument refers
to an array rather than a structure. The elements of this array
are timeval structures, which allow a precision of 1 microsecond
for specifying timestamps. The timeval structure is:
struct timeval {
long tv_sec; /* seconds */
long tv_usec; /* microseconds */
};
times[0] specifies the new access time, and times[1] specifies the
new modification time. If times is NULL, then analogously to
utime(), the access and modification times of the file are set to
the current time.
On success, zero is returned. On error, -1 is returned, and errno
is set to indicate the error.
EACCES Search permission is denied for one of the directories in
the path prefix of path (see also path_resolution(7)).
EACCES times is NULL, the caller's effective user ID does not
match the owner of the file, the caller does not have write
access to the file, and the caller is not privileged
(Linux: does not have either the CAP_DAC_OVERRIDE or the
CAP_FOWNER capability).
EFAULT filename points to an invalid address.
ENOENT filename does not exist.
EPERM times is not NULL, the caller's effective UID does not
match the owner of the file, and the caller is not
privileged (Linux: does not have the CAP_FOWNER
capability).
EROFS path resides on a read-only filesystem.
POSIX.1-2008.
utime()
SVr4, POSIX.1-2001. POSIX.1-2008 marks it as obsolete.
utimes()
4.3BSD, POSIX.1-2001.
Linux does not allow changing the timestamps on an immutable file,
or setting the timestamps to something other than the current time
on an append-only file.
chattr(1), touch(1), futimesat(2), stat(2), utimensat(2),
futimens(3), futimes(3), inode(7)
This page is part of the man-pages (Linux kernel and C library
user-space interface documentation) project. Information about
the project can be found at
⟨https://www.kernel.org/doc/man-pages/⟩. If you have a bug report
for this manual page, see
⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
This page was obtained from the tarball man-pages-6.10.tar.gz
fetched from
⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on
2025-02-02. If you discover any rendering problems in this HTML
version of the page, or you believe there is a better or more up-
to-date source for the page, or you have corrections or
improvements to the information in this COLOPHON (which is not
part of the original manual page), send a mail to
man-pages@man7.org
Linux man-pages 6.10 2024-07-23 utime(2)
Pages that refer to this page: indent(1), fcntl(2), futimesat(2), stat(2), statx(2), syscalls(2), utimensat(2), ctime(3), futimes(3), timeval(3type), capabilities(7), inode(7), landlock(7), signal-safety(7), time(7), mount(8)
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HTML rendering created 2025-02-02 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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