f14fb60209
* Updating common/lib * Updating lib/csu * Updating lib/libc * Updating libexec/ld.elf_so * Corrected test on __minix in featuretest to actually follow the meaning of the comment. * Cleaned up _REENTRANT-related defintions. * Disabled -D_REENTRANT for libfetch * Removing some unneeded __NBSD_LIBC defines and tests Change-Id: Ic1394baef74d11b9f86b312f5ff4bbc3cbf72ce2
107 lines
3.2 KiB
Groff
107 lines
3.2 KiB
Groff
.\" $NetBSD: time.3,v 1.16 2011/11/05 18:17:29 christos Exp $
|
|
.\"
|
|
.\" Copyright (c) 1989, 1991, 1993
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" This code is derived from software contributed to Berkeley by
|
|
.\" the American National Standards Committee X3, on Information
|
|
.\" Processing Systems.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" @(#)time.3 8.1 (Berkeley) 6/4/93
|
|
.\"
|
|
.Dd November 5, 2011
|
|
.Dt TIME 3
|
|
.Os
|
|
.Sh NAME
|
|
.Nm time
|
|
.Nd get time of day
|
|
.Sh LIBRARY
|
|
.Lb libc
|
|
.Sh SYNOPSIS
|
|
.In time.h
|
|
.Ft time_t
|
|
.Fn time "time_t *tloc"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn time
|
|
function
|
|
returns the value of time in seconds since 0 hours, 0 minutes,
|
|
0 seconds, January 1, 1970, Coordinated Universal Time.
|
|
.Pp
|
|
A copy of the time value may be saved to the area indicated by the
|
|
pointer
|
|
.Fa tloc .
|
|
If
|
|
.Fa tloc
|
|
is a
|
|
.Dv NULL
|
|
pointer, no value is stored.
|
|
.Pp
|
|
Upon successful completion,
|
|
.Fn time
|
|
returns the value of time.
|
|
Otherwise a value of
|
|
.Po
|
|
.Po Fa time_t Pc \-1
|
|
.Pc
|
|
is returned and the global variable
|
|
.Va errno
|
|
is set to indicate the error.
|
|
.Sh ERRORS
|
|
No errors are defined.
|
|
.Sh SEE ALSO
|
|
.Xr gettimeofday 2 ,
|
|
.Xr ctime 3
|
|
.Sh STANDARDS
|
|
The
|
|
.Fn time
|
|
function conforms to
|
|
.St -p1003.1-90 .
|
|
.Sh HISTORY
|
|
A
|
|
.Fn time
|
|
function appeared in
|
|
.At v2 .
|
|
It returned a 32-bit value measuring sixtieths of a second, leading to
|
|
rollover every 2.26 years.
|
|
In
|
|
.At v6 ,
|
|
the precision of
|
|
.Fn time
|
|
was changed to seconds, allowing 135.6 years between rollovers.
|
|
.Pp
|
|
In
|
|
.Nx 6.0
|
|
the
|
|
.Vt time_t
|
|
type was changed to be 64 bits wide, including on 32-bit machines,
|
|
making rollover a concern for the far distant future only.
|
|
Note however that any code making the incorrect assumption that
|
|
.Vt time_t
|
|
is the same as
|
|
.Vt long
|
|
will fail on 32-bit machines in 2038.
|