freebsd-dev/share/man/man3/timeradd.3
Benedict Reuschling 55ed6718c2 Fix various, mostly minor errors in man pages like:
- Abbreviated month name in .Dd
- position of HISTORY section
- alphabetical ordering within SEE ALSO section
- adding .Ed before .Sh DESCRIPTION
- remove trailing whitespaces
- Line break after a sentence stop
- Use BSD OS macros instead of hardcoded strings

No .Dd bumps as there was no actual content change made
in any of these pages.

Submitted by:	Gordon Bergling gbergling_gmail.com
Approved by:	bcr
Differential Revision:	https://reviews.freebsd.org/D24591
2020-05-03 10:15:58 +00:00

166 lines
4.1 KiB
Groff

.\" Copyright (c) 1999 Kelly Yancey <kbyanc@posi.net>
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.\" $FreeBSD$
.\"
.Dd July 30, 2018
.Dt TIMERADD 3
.Os
.Sh NAME
.Nm timeradd ,
.Nm timersub ,
.Nm timerclear ,
.Nm timerisset ,
.Nm timercmp ,
.Nm timespecadd ,
.Nm timespecsub ,
.Nm timespecclear ,
.Nm timespecisset ,
.Nm timespeccmp
.Nd operations on timevals and timespecs
.Sh SYNOPSIS
.In sys/time.h
.Ft void
.Fn timeradd "struct timeval *a" "struct timeval *b" "struct timeval *res"
.Ft void
.Fn timersub "struct timeval *a" "struct timeval *b" "struct timeval *res"
.Ft void
.Fn timerclear "struct timeval *tvp"
.Ft int
.Fn timerisset "struct timeval *tvp"
.Ft int
.Fn timercmp "struct timeval *a" "struct timeval *b" CMP
.Ft void
.Fn timespecadd "struct timespec *a" "struct timespec *b" "struct timespec *res"
.Ft void
.Fn timespecsub "struct timespec *a" "struct timespec *b" "struct timespec *res"
.Ft void
.Fn timespecclear "struct timespec *ts"
.Ft int
.Fn timespecisset "struct timespec *ts"
.Ft int
.Fn timespeccmp "struct timespec *a" "struct timespec *b" CMP
.Sh DESCRIPTION
These macros are provided for manipulating
.Fa timeval
and
.Fa timespec
structures for use with the
.Xr clock_gettime 2 ,
.Xr clock_settime 2 ,
.Xr gettimeofday 2
and
.Xr settimeofday 2
calls.
The
.Fa timeval
structure is defined in
.In sys/time.h
as:
.Bd -literal
struct timeval {
long tv_sec; /* seconds since Jan. 1, 1970 */
long tv_usec; /* and microseconds */
};
.Ed
And the
.Fa timespec
structure is defined in
.In time.h
as:
.Bd -literal
struct timespec {
time_t tv_sec; /* seconds */
long tv_nsec; /* and nanoseconds */
};
.Ed
.Pp
.Fn timeradd
and
.Fn timespecadd
add the time information stored in
.Fa a
to
.Fa b
and store the result in
.Fa res .
The results are simplified such that the value of
.Fa res->tv_usec
or
.Fa res->tv_nsec
is always less than 1 second.
.Pp
.Fn timersub
and
.Fn timespecsub
subtract the time information stored in
.Fa b
from
.Fa a
and store the result
in
.Fa res .
.Pp
.Fn timerclear
and
.Fn timespecclear
initialize their argument to midnight (0 hour) January 1st, 1970 (the Epoch).
.Pp
.Fn timerisset
and
.Fn timespecisset
return true if their argument is set to any time value other than the Epoch.
.Pp
.Fn timercmp
and
.Fn timespeccmp
compare
.Fa a
to
.Fa b
using the comparison operator given in
.Fa CMP ,
and return the result of that comparison.
.Sh SEE ALSO
.Xr clock_gettime 2 ,
.Xr gettimeofday 2
.Sh HISTORY
The
.Fn timeradd
family of macros were imported from
.Nx 1.1 ,
and appeared in
.Fx 2.2.6 .
The
.Fn timespecadd
family of macros were imported from
.Nx 1.3
into
.Fx 3.0 ,
though they were not exposed to userland until
.Fx 12.0 .