minix/lib/libc/gen/time.3
Lionel Sambuc f14fb60209 Libraries updates and cleanup
* 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
2013-01-14 11:36:26 +01:00

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.
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.\" @(#)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.