1.\" $OpenBSD: time.3,v 1.16 2015/01/29 01:46:30 schwarze Exp $ 2.\" 3.\" Copyright (c) 1989, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" This code is derived from software contributed to Berkeley by 7.\" the American National Standards Committee X3, on Information 8.\" Processing Systems. 9.\" 10.\" Redistribution and use in source and binary forms, with or without 11.\" modification, are permitted provided that the following conditions 12.\" are met: 13.\" 1. Redistributions of source code must retain the above copyright 14.\" notice, this list of conditions and the following disclaimer. 15.\" 2. Redistributions in binary form must reproduce the above copyright 16.\" notice, this list of conditions and the following disclaimer in the 17.\" documentation and/or other materials provided with the distribution. 18.\" 3. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.Dd $Mdocdate: January 29 2015 $ 35.Dt TIME 3 36.Os 37.Sh NAME 38.Nm time 39.Nd get time of day 40.Sh SYNOPSIS 41.In time.h 42.Ft time_t 43.Fn time "time_t *tloc" 44.Sh DESCRIPTION 45The 46.Fn time 47function returns the value of time in seconds since 0 hours, 0 minutes, 480 seconds, January 1, 1970, Coordinated Universal Time (UTC). 49.Pp 50A copy of the time value may be saved to the area indicated by the 51pointer 52.Fa tloc . 53If 54.Fa tloc 55is a null pointer, no value is stored. 56.Sh RETURN VALUES 57Upon successful completion, 58.Fn time 59returns the value of time. 60Otherwise a value of 61.Po Fa time_t Pc Ns -1 62is returned and the global variable 63.Va errno 64is set to indicate the error. 65.Sh ERRORS 66The following error codes may be set in 67.Va errno : 68.Bl -tag -width Er 69.It Bq Er EFAULT 70An argument address referenced invalid memory. 71.El 72.Sh SEE ALSO 73.Xr clock_gettime 2 , 74.Xr gettimeofday 2 , 75.Xr ctime 3 76.Sh HISTORY 77A 78.Fn time 79system call first appeared in 80.At v1 81and used to return time in sixtieths of a second in 32 bits, 82which was to guarantee a crisis every 2.26 years. 83Since 84.At v6 , 85.Fn time 86scale was changed to seconds, extending the pre-crisis stagnation 87period up to a total of 68 years. 88