.\" Copyright (c) 1992 Drew Eckhardt (drew@cs.colorado.edu), March 28, 1992

.\"

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.\" 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@gmail.com>

.\" Modified 2004-10-10 by Andries Brouwer <aeb@cwi.nl>

.\"

.TH UTIME 2 2017-09-15 "Linux" "Linux Programmer's Manual"

.SH NAME

utime, utimes \- change file last access and modification times

.SH SYNOPSIS

.nf

.B #include <sys/types.h>

.B #include <utime.h>

.PP

.BI "int utime(const char *" filename ", const struct utimbuf *" times );

.PP

.B #include <sys/time.h>

.PP

.BI "int utimes(const char *" filename ", const struct timeval " times [2]);

.fi

.SH DESCRIPTION

.B Note:

modern applications may prefer to use the interfaces described in

.BR utimensat (2).

.PP

The

.BR utime ()

system call

changes the access and modification times of the inode specified by

.I filename

to the

.IR actime " and " modtime

fields of

.I times

respectively.

.PP

If

.I times

is NULL, then the access and modification times of the file are set

to the current time.

.PP

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

is NULL and the process has write permission for the file.

.PP

The

.I utimbuf

structure is:

.PP

.in +4n

.EX

struct utimbuf {

    time_t actime;       /* access time */

    time_t modtime;      /* modification time */

};

.EE

.in

.PP

The

.BR utime ()

system call

allows specification of timestamps with a resolution of 1 second.

.PP

The

.BR utimes ()

system call

is similar, but the

.I times

argument refers to an array rather than a structure.

The elements of this array are

.I timeval

structures, which allow a precision of 1 microsecond for specifying timestamps.

The

.I timeval

structure is:

.PP

.in +4n

.EX

struct timeval {

    long tv_sec;        /* seconds */

    long tv_usec;       /* microseconds */

};

.EE

.in

.PP

.IR times [0]

specifies the new access time, and

.IR times [1]

specifies the new modification time.

If

.I times

is NULL, then analogously to

.BR utime (),

the access and modification times of the file are

set to the current time.

.SH RETURN VALUE

On success, zero is returned.

On error, \-1 is returned, and

.I errno

is set appropriately.

.SH ERRORS

.TP

.B EACCES

Search permission is denied for one of the directories in

the path prefix of

.I path

(see also

.BR path_resolution (7)).

.TP

.B EACCES

.I 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

.B CAP_DAC_OVERRIDE

or the

.B CAP_FOWNER

capability).

.TP

.B ENOENT

.I filename

does not exist.

.TP

.B EPERM

.I 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

.B CAP_FOWNER

capability).

.TP

.B EROFS

.I path

resides on a read-only filesystem.

.SH CONFORMING TO

.BR utime ():

SVr4, POSIX.1-2001.

POSIX.1-2008 marks

.BR utime ()

as obsolete.

.PP

.BR utimes ():

4.3BSD, POSIX.1-2001.

.SH 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 append-only file.

.\"

.\" In libc4 and libc5,

.\" .BR utimes ()

.\" is just a wrapper for

.\" .BR utime ()

.\" and hence does not allow a subsecond resolution.

.SH SEE ALSO

.BR chattr (1),

.BR touch (1),

.BR futimesat (2),

.BR stat (2),

.BR utimensat (2),

.BR futimens (3),

.BR futimes (3),

.BR inode (7)

.SH COLOPHON

This page is part of release 4.15 of the Linux

.I man-pages

project.

A description of the project,

information about reporting bugs,

and the latest version of this page,

can be found at

\%https://www.kernel.org/doc/man\-pages/.