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.TH UTIME "3P" 2013 "IEEE/The Open Group" "POSIX Programmer's Manual"

.SH PROLOG

This manual page is part of the POSIX Programmer's Manual.

The Linux implementation of this interface may differ (consult

the corresponding Linux manual page for details of Linux behavior),

or the interface may not be implemented on Linux.

.SH NAME

utime

\(em set file access and modification times

.SH SYNOPSIS

.LP

.nf

#include <utime.h>

.P

int utime(const char *\fIpath\fP, const struct utimbuf *\fItimes\fP);

.fi

.SH DESCRIPTION

The

\fIutime\fR()

function shall set the access and modification times of the file named

by the

.IR path

argument.

.P

If

.IR times

is a null pointer, the access and modification times of the file shall

be set to the current time. The effective user ID of the process shall

match the owner of the file, or the process has write permission to the

file or has appropriate privileges, to use

\fIutime\fR()

in this manner.

.P

If

.IR times

is not a null pointer,

.IR times

shall be interpreted as a pointer to a

.BR utimbuf

structure and the access and modification times shall be set to the

values contained in the designated structure. Only a process with

the effective user ID equal to the user ID of the file or a process with

appropriate privileges may use

\fIutime\fR()

this way.

.P

The

.BR utimbuf

structure is defined in the

.IR <utime.h> 

header. The times in the structure

.BR utimbuf

are measured in seconds since the Epoch.

.P

Upon successful completion, the

\fIutime\fR()

function shall mark the last file status change timestamp

for update; see

.IR <sys/stat.h> .

.SH "RETURN VALUE"

Upon successful completion, 0 shall be returned. Otherwise, \(mi1

shall be returned and

.IR errno

shall be set to indicate the error, and the file times shall not be

affected.

.SH ERRORS

The

\fIutime\fR()

function shall fail if:

.TP

.BR EACCES

Search permission is denied by a component of the path prefix; or the

.IR times

argument is a null pointer and the effective user ID of the process

does not match the owner of the file, the process does not have write

permission for the file, and the process does not have appropriate

privileges.

.TP

.BR ELOOP

A loop exists in symbolic links encountered during resolution of the

.IR path

argument.

.TP

.BR ENAMETOOLONG

.br

The length of a component of a pathname is longer than

{NAME_MAX}.

.TP

.BR ENOENT

A component of

.IR path

does not name an existing file or

.IR path

is an empty string.

.TP

.BR ENOTDIR

A component of the path prefix names an existing file that is neither

a directory nor a symbolic link to a directory, or the

.IR path

argument contains at least one non-\c

<slash>

character and ends with one or more trailing

<slash>

characters and the last pathname component names an existing file

that is neither a directory nor a symbolic link to a directory.

.TP

.BR EPERM

The

.IR times

argument is not a null pointer and the effective user ID of the calling

process does not match the owner of the file and the calling process

does not have appropriate privileges.

.TP

.BR EROFS

The file system containing the file is read-only.

.br

.P

The

\fIutime\fR()

function may fail if:

.TP

.BR ELOOP

More than

{SYMLOOP_MAX}

symbolic links were encountered during resolution of the

.IR path

argument.

.TP

.BR ENAMETOOLONG

.br

The length of a pathname exceeds

{PATH_MAX},

or pathname resolution of a symbolic link produced an intermediate

result with a length that exceeds

{PATH_MAX}.

.LP

.IR "The following sections are informative."

.SH EXAMPLES

None.

.SH "APPLICATION USAGE"

Since the

.BR utimbuf

structure only contains

.BR time_t

variables and is not accurate to fractions of a second,

applications should use the

\fIutimensat\fR()

function instead of the obsolescent

\fIutime\fR()

function.

.SH RATIONALE

The

.IR actime

structure member must be present so that an application may set it,

even though an implementation may ignore it and not change the last data

access timestamp on the file. If an application intends to leave one of

the times of a file unchanged while changing the other, it should use

\fIstat\fR()

or

\fIfstat\fR()

to retrieve the file's

.IR st_atim

and

.IR st_mtim

parameters, set

.IR actime

and

.IR modtime

in the buffer, and change one of them before making the

\fIutime\fR()

call.

.SH "FUTURE DIRECTIONS"

The

\fIutime\fR()

function may be removed in a future version.

.SH "SEE ALSO"

.IR "\fIfstat\fR\^(\|)",

.IR "\fIfstatat\fR\^(\|)",

.IR "\fIfutimens\fR\^(\|)"

.P

The Base Definitions volume of POSIX.1\(hy2008,

.IR "\fB<sys_stat.h>\fP",

.IR "\fB<utime.h>\fP"

.SH COPYRIGHT

Portions of this text are reprinted and reproduced in electronic form

from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology

-- Portable Operating System Interface (POSIX), The Open Group Base

Specifications Issue 7, Copyright (C) 2013 by the Institute of

Electrical and Electronics Engineers, Inc and The Open Group.

(This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the

event of any discrepancy between this version and the original IEEE and

The Open Group Standard, the original IEEE and The Open Group Standard

is the referee document. The original Standard can be obtained online at

http://www.unix.org/online.html .

Any typographical or formatting errors that appear

in this page are most likely

to have been introduced during the conversion of the source files to

man page format. To report such errors, see

https://www.kernel.org/doc/man-pages/reporting_bugs.html .