1
0
mirror of https://git.FreeBSD.org/src.git synced 2024-12-24 11:29:10 +00:00
freebsd/share/man/man3/timeradd.3
Doug White e5606f14a9 Add manpage for timeradd macros and friends. A companion page for
timespecadd should be added at a future point...

PR:		13079
2002-01-14 00:38:20 +00:00

122 lines
3.1 KiB
Groff

.\" Copyright (c) 1999 Kelly Yancey <kbyanc@posi.net>
.\" All rights reserved.
.\"
.\" 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 author nor the names of any co-contributors
.\" may be used to endorse or promote products derived from this software
.\" without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL 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.
.\"
.\" $FreeBSD$
.\"
.Dd Aug 11, 1999
.Dt TIMERADD 3
.Os BSD 4
.Sh NAME
.Nm timeradd ,
.Nm timersub ,
.Nm timerclear ,
.Nm timerisset ,
.Nm timercmp
.Nd operations on timevals
.Sh SYNOPSIS
.Fd #include <sys/time.h>
.Fn timeradd "&tvp" "&uvp" "&vvp"
.Fn timersub "&tvp" "&uvp" "&vvp"
.Fn timerclear "&tvp"
.Fn timerisset "&tvp"
.Fn timercmp "&tvp" "&uvp" "cmp"
.Sh DESCRIPTION
.Pp
These macros are provided for manipulating
.Fa timeval
structures for use with the
.Fn gettimeofday
and
.Fn settimeofday
calls.
The structures pointed to by
.Fa tvp ,
.Fa uvp ,
and
.Fa vvp
are defined in
.Ao Pa sys/time.h Ac
as:
.Pp
.Bd -literal
struct timeval {
long tv_sec; /* seconds since Jan. 1, 1970 */
long tv_usec; /* and microseconds */
};
.Ed
.Pp
.Fn timeradd
adds the time information stored in
.Fa uvp
to
.Fa tvp
and stores the resulting
.Fa timeval
in
.Fa vvp .
The results are simplified such that the value of
.Fa vvp->tv_usec
is always less than 1,000,000 (1 second).
.Pp
.Fn timersub
subtracts the time information stored in
.Fa uvp
from
.Fa tvp
and stores the resulting
.Fa timeval
in
.Fa vvp .
.Pp
.Fn timerclear
initializes
.Fa tvp
to midnight (0 hour) January 1st, 1970 (the Epoch).
.Pp
.Fn timerisset
returns true if
.Fa tvp
is set to any time value other than the Epoch.
.Pp
.Fn timercmp
compares
.Fa tvp
to
.Fa uvp
using the comparison operator given in
.Fa cmp
and returns the result of that comparison.
.Sh SEE ALSO
.Xr gettimeofday 2
.Sh HISTORY
The
.Fn timeradd
family of macros were imported from
.Nx 1.1 ,
and appeared in
.Fx 2.2.6 .