Name
utime, utimes — change access and/or modification
times of an inode
Synopsis
int
utime( |
const char * |
filename, |
| |
const struct utimbuf
* |
buf); |
#include <sys/time.h>
int
utimes( |
const char * |
filename, |
| |
const struct timeval
|
times); |
DESCRIPTION
utime() changes the access
and modification times of the inode specified by filename to the actime and modtime fields of buf respectively.
If buf is NULL,
then the access and modification times of the file are set to
the current time.
Changing time stamps is permitted when: either the process
has appropriate privileges (Linux: has the CAP_FOWNER capability), or the effective
user ID equals the user ID of the file, or buf must is NULL and the
process has write permission to the file.
The utimbuf
structure is:
| struct |
utimbuf { |
| |
time_t |
|
actime; |
/* access time */ |
| |
time_t |
|
modtime; |
/* modification time */ |
| }; |
The function utime() allows
specification of time stamps with a resolution of 1 second.
The function utimes() is
similar, but allows a resolution of 1 microsecond. Here
times[0] refers to
access time, and times[1] to modification
time.
The timeval
structure is:
| struct |
timeval { |
| |
long |
|
tv_sec; |
/* seconds */ |
| |
long |
|
tv_usec; |
/* microseconds */ |
| }; |
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)),
or buf is NULL
and the process does not have permission to change the
time stamps (see above).
- ENOENT
-
filename
does not exist.
- EPERM
-
buf is not
NULL and the process does not have permission to change
the time stamps.
- EROFS
-
path
resides on a read-only file system.
CONFORMING TO
utime(): SVr4,
POSIX.1-2001.
utimes(): 4.3BSD
NOTES
Linux does not allow changing the time stamps on an
immutable file, or setting the time stamps 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.
POSIX.1-2001 marks utimes()
legacy, which is strange since it provides more functionality
than utime().
BUGS
Linux is not careful to distinguish between the EACCES and
EPERM error returns. On the other hand, POSIX.1-2001 is buggy
in its error description for utimes().
SEE ALSO
chattr(1), futimesat(2), stat(2), futimes(3)
Copyright (c) 1992 Drew Eckhardt (drew@cs.colorado.edu), March 28, 1992
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Formatted or processed versions of this manual, if unaccompanied by
the source, must acknowledge the copyright and authors of this work.
Modified by Michael Haardt <michael@moria.de>
Modified 1993-07-24 by Rik Faith <faith@cs.unc.edu>
Modified 1995-06-10 by Andries Brouwer <aeb@cwi.nl>
Modified 2004-06-23 by Michael Kerrisk <mtk-manpages@gmx.net>
Modified 2004-10-10 by Andries Brouwer <aeb@cwi.nl>
|
