UTIME
Section: Linux Programmer's Manual (2)
Updated: 2008-08-06
NAME
utime, utimes - change file last access and modification times
SYNOPSIS
#include <sys/types.h>
#include <utime.h>
int utime(const char *filename, const struct utimbuf *times);
#include <sys/time.h>
int utimes(const char *filename, const struct timeval times[2]);
DESCRIPTION
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.
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.
RETURN VALUE
On success, zero is returned.
On error, -1 is returned, and
errno
is set appropriately.
ERRORS
- 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).
- 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 file system.
CONFORMING TO
utime():
SVr4, POSIX.1-2001.
POSIX.1-2008 marks
utime()
as obsolete.
utimes():
4.3BSD, POSIX.1-2001.
NOTES
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.
In libc4 and libc5,
utimes()
is just a wrapper for
utime()
and hence does not allow a subsecond resolution.
SEE ALSO
chattr(1),
futimesat(2),
stat(2),
utimensat(2),
futimes(3),
futimens(3)
COLOPHON
This page is part of release 3.27 of the Linux
man-pages
project.
A description of the project,
and information about reporting bugs,
can be found at
http://www.kernel.org/doc/man-pages/.
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ERRORS
-
- CONFORMING TO
-
- NOTES
-
- SEE ALSO
-
- COLOPHON
-
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Time: 07:34:57 GMT, March 26, 2013