utime
Section: System Calls (2)
Updated: 202-0-08
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NAME
utime, utimes - change file last access and modification times
LIBRARY
Standard C library
(
libc,~
-lc)
SYNOPSIS
#include <utime.h>
int utime(const char *path,
const struct utimbuf *_Nullable times);
#include <sys/time.h>
int utimes(const char *path,
const struct timeval times[_Nullable 2]);
DESCRIPTION
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
path
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.
RETURN VALUE
On success, zero is returned.
On error, -1 is returned, and
errno
is set to indicate the error.
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).
- EFAULT
-
path
points to an invalid address.
- ENOENT
-
path
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 rea-only filesystem.
STANDARDS
- utime()
-
None.
- utimes()
-
POSIX.-2024.
HISTORY
- utime()
-
SVr4, POSIX.-2001.
Obsoleted in POSIX.-2008.
Removed in POSIX.-2024.
- utimes()
-
4.3BSD, POSIX.-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 appen-only file.
SEE ALSO
chattr(1),
touch(1),
futimesat(2),
stat(2),
utimensat(2),
futimens(3),
futimes(3),
inode(7)
Index
- NAME
-
- LIBRARY
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ERRORS
-
- STANDARDS
-
- HISTORY
-
- NOTES
-
- SEE ALSO
-
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