1.\" Copyright (c) 1989, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" the American National Standards Committee X3, on Information 6.\" Processing Systems. 7.\" 8.\" Redistribution and use in source and binary forms, with or without 9.\" modification, are permitted provided that the following conditions 10.\" are met: 11.\" 1. Redistributions of source code must retain the above copyright 12.\" notice, this list of conditions and the following disclaimer. 13.\" 2. Redistributions in binary form must reproduce the above copyright 14.\" notice, this list of conditions and the following disclaimer in the 15.\" documentation and/or other materials provided with the distribution. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)time.3 8.1 (Berkeley) 6/4/93 33.\" $FreeBSD: src/lib/libc/gen/time.3,v 1.15 2007/01/09 00:27:55 imp Exp $ 34.\" $DragonFly: src/lib/libc/gen/time.3,v 1.2 2003/06/17 04:26:42 dillon Exp $ 35.\" 36.Dd July 18, 2003 37.Dt TIME 3 38.Os 39.Sh NAME 40.Nm time 41.Nd get time of day 42.Sh LIBRARY 43.Lb libc 44.Sh SYNOPSIS 45.In time.h 46.Ft time_t 47.Fn time "time_t *tloc" 48.Sh DESCRIPTION 49The 50.Fn time 51function 52returns the value of time in seconds since 0 hours, 0 minutes, 530 seconds, January 1, 1970, Coordinated Universal Time. 54If an error occurs, 55.Fn time 56returns the value 57.Po Vt time_t Pc Ns \-1 . 58.Pp 59The return value is also stored in 60.No \&* Ns Va tloc , 61provided that 62.Va tloc 63is non-null. 64.Sh ERRORS 65The 66.Fn time 67function may fail for any of the reasons described in 68.Xr gettimeofday 2 . 69.Sh SEE ALSO 70.Xr gettimeofday 2 , 71.Xr ctime 3 72.Sh STANDARDS 73The 74.Nm 75function conforms to 76.St -p1003.1-2001 . 77.Sh HISTORY 78A 79.Fn time 80function appeared in 81.At v6 . 82.Sh BUGS 83Neither 84.St -isoC-99 85nor 86.St -p1003.1-2001 87requires 88.Fn time 89to set 90.Va errno 91on failure; thus, it is impossible for an application to distinguish 92the valid time value \-1 (representing the last UTC second of 1969) 93from the error return value. 94.Pp 95Systems conforming to earlier versions of the C and 96.Tn POSIX 97standards (including older versions of 98.Fx ) 99did not set 100.No \&* Ns Va tloc 101in the error case. 102