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<H1>UTIME</H1>
Section: Linux Programmer's Manual (2)<BR>Updated: 2017-09-15<BR><A HREF="#index">Index</A>
<A HREF="/cgi-bin/man/man2html">Return to Main Contents</A><HR>
<A NAME="lbAB">&nbsp;</A>
<H2>NAME</H2>
utime, utimes - change file last access and modification times
<A NAME="lbAC">&nbsp;</A>
<H2>SYNOPSIS</H2>
<PRE>
<B>#include &lt;<A HREF="file:///usr/include/sys/types.h">sys/types.h</A>&gt;</B>
<B>#include &lt;<A HREF="file:///usr/include/utime.h">utime.h</A>&gt;</B>
<B>int utime(const char *</B><I>filename</I><B>, const struct utimbuf *</B><I>times</I><B>);</B>
<B>#include &lt;<A HREF="file:///usr/include/sys/time.h">sys/time.h</A>&gt;</B>
<B>int utimes(const char *</B><I>filename</I><B>, const struct timeval </B><I>times</I><B>[2]);</B>
</PRE>
<A NAME="lbAD">&nbsp;</A>
<H2>DESCRIPTION</H2>
<B>Note:</B>
modern applications may prefer to use the interfaces described in
<B><A HREF="/cgi-bin/man/man2html?2+utimensat">utimensat</A></B>(2).
<P>
The
<B>utime</B>()
system call
changes the access and modification times of the inode specified by
<I>filename</I>
to the
<I>actime</I> and <I>modtime</I>
fields of
<I>times</I>
respectively.
<P>
If
<I>times</I>
is NULL, then the access and modification times of the file are set
to the current time.
<P>
Changing timestamps is permitted when: either
the process has appropriate privileges,
or the effective user ID equals the user ID
of the file, or
<I>times</I>
is NULL and the process has write permission for the file.
<P>
The
<I>utimbuf</I>
structure is:
<P>
struct utimbuf {
<BR>&nbsp;&nbsp;&nbsp;&nbsp;time_t&nbsp;actime;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;/*&nbsp;access&nbsp;time&nbsp;*/
<BR>&nbsp;&nbsp;&nbsp;&nbsp;time_t&nbsp;modtime;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;/*&nbsp;modification&nbsp;time&nbsp;*/
};
<P>
The
<B>utime</B>()
system call
allows specification of timestamps with a resolution of 1 second.
<P>
The
<B>utimes</B>()
system call
is similar, but the
<I>times</I>
argument refers to an array rather than a structure.
The elements of this array are
<I>timeval</I>
structures, which allow a precision of 1 microsecond for specifying timestamps.
The
<I>timeval</I>
structure is:
<P>
struct timeval {
<BR>&nbsp;&nbsp;&nbsp;&nbsp;long&nbsp;tv_sec;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;/*&nbsp;seconds&nbsp;*/
<BR>&nbsp;&nbsp;&nbsp;&nbsp;long&nbsp;tv_usec;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;/*&nbsp;microseconds&nbsp;*/
};
<P>
<I>times</I>[0]
specifies the new access time, and
<I>times</I>[1]
specifies the new modification time.
If
<I>times</I>
is NULL, then analogously to
<B>utime</B>(),
the access and modification times of the file are
set to the current time.
<A NAME="lbAE">&nbsp;</A>
<H2>RETURN VALUE</H2>
On success, zero is returned.
On error, -1 is returned, and
<I>errno</I>
is set appropriately.
<A NAME="lbAF">&nbsp;</A>
<H2>ERRORS</H2>
<DL COMPACT>
<DT id="1"><B>EACCES</B>
<DD>
Search permission is denied for one of the directories in
the path prefix of
<I>path</I>
(see also
<B><A HREF="/cgi-bin/man/man2html?7+path_resolution">path_resolution</A></B>(7)).
<DT id="2"><B>EACCES</B>
<DD>
<I>times</I>
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
<B>CAP_DAC_OVERRIDE</B>
or the
<B>CAP_FOWNER</B>
capability).
<DT id="3"><B>ENOENT</B>
<DD>
<I>filename</I>
does not exist.
<DT id="4"><B>EPERM</B>
<DD>
<I>times</I>
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
<B>CAP_FOWNER</B>
capability).
<DT id="5"><B>EROFS</B>
<DD>
<I>path</I>
resides on a read-only filesystem.
</DL>
<A NAME="lbAG">&nbsp;</A>
<H2>CONFORMING TO</H2>
<B>utime</B>():
SVr4, POSIX.1-2001.
POSIX.1-2008 marks
<B>utime</B>()
as obsolete.
<P>
<B>utimes</B>():
4.3BSD, POSIX.1-2001.
<A NAME="lbAH">&nbsp;</A>
<H2>NOTES</H2>
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.
<A NAME="lbAI">&nbsp;</A>
<H2>SEE ALSO</H2>
<B><A HREF="/cgi-bin/man/man2html?1+chattr">chattr</A></B>(1),
<B><A HREF="/cgi-bin/man/man2html?1+touch">touch</A></B>(1),
<B><A HREF="/cgi-bin/man/man2html?2+futimesat">futimesat</A></B>(2),
<B><A HREF="/cgi-bin/man/man2html?2+stat">stat</A></B>(2),
<B><A HREF="/cgi-bin/man/man2html?2+utimensat">utimensat</A></B>(2),
<B><A HREF="/cgi-bin/man/man2html?3+futimens">futimens</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+futimes">futimes</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?7+inode">inode</A></B>(7)
<A NAME="lbAJ">&nbsp;</A>
<H2>COLOPHON</H2>
This page is part of release 5.05 of the Linux
<I>man-pages</I>
project.
A description of the project,
information about reporting bugs,
and the latest version of this page,
can be found at
<A HREF="https://www.kernel.org/doc/man-pages/.">https://www.kernel.org/doc/man-pages/.</A>
<P>
<HR>
<A NAME="index">&nbsp;</A><H2>Index</H2>
<DL>
<DT id="6"><A HREF="#lbAB">NAME</A><DD>
<DT id="7"><A HREF="#lbAC">SYNOPSIS</A><DD>
<DT id="8"><A HREF="#lbAD">DESCRIPTION</A><DD>
<DT id="9"><A HREF="#lbAE">RETURN VALUE</A><DD>
<DT id="10"><A HREF="#lbAF">ERRORS</A><DD>
<DT id="11"><A HREF="#lbAG">CONFORMING TO</A><DD>
<DT id="12"><A HREF="#lbAH">NOTES</A><DD>
<DT id="13"><A HREF="#lbAI">SEE ALSO</A><DD>
<DT id="14"><A HREF="#lbAJ">COLOPHON</A><DD>
</DL>
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Time: 00:05:35 GMT, March 31, 2021
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