1.\" Copyright (c) 1999 Kelly Yancey <kbyanc@posi.net> 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. Neither the name of the author nor the names of any co-contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" $FreeBSD$ 29.\" 30.Dd Aug 11, 1999 31.Dt TIMERADD 3 32.Os BSD 4 33.Sh NAME 34.Nm timeradd , 35.Nm timersub , 36.Nm timerclear , 37.Nm timerisset , 38.Nm timercmp 39.Nd operations on timevals 40.Sh SYNOPSIS 41.Fd #include <sys/time.h> 42.Fn timeradd "&tvp" "&uvp" "&vvp" 43.Fn timersub "&tvp" "&uvp" "&vvp" 44.Fn timerclear "&tvp" 45.Fn timerisset "&tvp" 46.Fn timercmp "&tvp" "&uvp" "cmp" 47.Sh DESCRIPTION 48.Pp 49These macros are provided for manipulating 50.Fa timeval 51structures for use with the 52.Fn gettimeofday 53and 54.Fn settimeofday 55calls. 56The structures pointed to by 57.Fa tvp , 58.Fa uvp , 59and 60.Fa vvp 61are defined in 62.Ao Pa sys/time.h Ac 63as: 64.Pp 65.Bd -literal 66struct timeval { 67 long tv_sec; /* seconds since Jan. 1, 1970 */ 68 long tv_usec; /* and microseconds */ 69}; 70.Ed 71.Pp 72.Fn timeradd 73adds the time information stored in 74.Fa uvp 75to 76.Fa tvp 77and stores the resulting 78.Fa timeval 79in 80.Fa vvp . 81The results are simplified such that the value of 82.Fa vvp->tv_usec 83is always less than 1,000,000 (1 second). 84.Pp 85.Fn timersub 86subtracts the time information stored in 87.Fa uvp 88from 89.Fa tvp 90and stores the resulting 91.Fa timeval 92in 93.Fa vvp . 94.Pp 95.Fn timerclear 96initializes 97.Fa tvp 98to midnight (0 hour) January 1st, 1970 (the Epoch). 99.Pp 100.Fn timerisset 101returns true if 102.Fa tvp 103is set to any time value other than the Epoch. 104.Pp 105.Fn timercmp 106compares 107.Fa tvp 108to 109.Fa uvp 110using the comparison operator given in 111.Fa cmp 112and returns the result of that comparison. 113.Sh SEE ALSO 114.Xr gettimeofday 2 115.Sh HISTORY 116The 117.Fn timeradd 118family of macros were imported from 119.Nx 1.1 , 120and appeared in 121.Fx 2.2.6 . 122