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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]); |
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;time_t modtime;};
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;long tv_usec;};
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.
Search permission is denied for one of the
directories in the path prefix of path (see also
path_resolution(7)).
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).
filename
does not exist.
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).
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.
In libc4 and libc5, utimes()
is just a wrapper for utime()
and hence does not allow a subsecond resolution.
This page is part of release 3.54 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/.
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Copyright (c) 1992 Drew Eckhardt (drewcs.colorado.edu), March 28, 1992 %%%LICENSE_START(VERBATIM) Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Since the Linux kernel and libraries are constantly changing, this manual page may be incorrect or out-of-date. The author(s) assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein. The author(s) may not have taken the same level of care in the production of this manual, which is licensed free of charge, as they might when working professionally. Formatted or processed versions of this manual, if unaccompanied by the source, must acknowledge the copyright and authors of this work. %%%LICENSE_END Modified by Michael Haardt <michaelmoria.de> Modified 1993-07-24 by Rik Faith <faithcs.unc.edu> Modified 1995-06-10 by Andries Brouwer <aebcwi.nl> Modified 2004-06-23 by Michael Kerrisk <mtk.manpagesgmail.com> Modified 2004-10-10 by Andries Brouwer <aebcwi.nl> |