UTIME(2) manual page
Table of Contents
utime, utimes - change file last access
and modification times
#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]);
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.
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 appropriately.
- 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 filesystem.
utime(): SVr4, POSIX.1-2001. POSIX.1-2008
marks utime() 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)
, futimesat(2)
,
stat(2)
, utimensat(2)
, futimens(3)
, futimes(3)
This page is part
of release 3.78 of the Linux man-pages project. A description of the project,
information about reporting bugs, and the latest version of this page,
can be found at http://www.kernel.org/doc/man-pages/.
Table of Contents