timerisset (3)

Leading comments

$NetBSD: timeradd.3,v 1.8 2010/06/07 18:40:16 jruoho Exp $

Copyright (c) 2009 Jukka Ruohonen <jruohonen@iki.fi>
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...

(The comments found at the beginning of the groff file "man3/timerisset.3bsd".)

NAME

timeradd timersub timerclear timerisset timercmp timespecadd timespecsub timespecclear timespecisset timespeccmp - operations on time structure

LIBRARY

Lb libbsd

SYNOPSIS

In sys/time.h (See libbsd(7) for include usage.) 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 *tv Ft int Fn timerisset struct timeval *tv 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

DESCRIPTION

These macros are provided for manipulating the Fa timeval and Fa timespec structures described in timeval(3bsd).

The Fn timeradd and Fn timespecadd macros add the time information stored in Fa a to Fa b , storing the result in Fa res . With Fn timeradd the results are simplified such that the value of Fa res->tv_usec is always less than 1,000,000 (1 second). With Fn timespecadd the Fa res->tv_nsec member of Fa struct timespec is always less than 1,000,000,000.

The Fn timersub and Fn timespecsub macros subtract the time information stored in Fa b from Fa a and store the resulting structure in Fa res .

The Fn timerclear and Fn timespecclear macros initialize the structures to midnight (0 hour) January 1st, 1970 (the Epoch). In other words, they set the members of the structure to zero.

The Fn timerisset and Fn timespecisset macros return true if the input structure is set to any time value other than the Epoch.

The Fn timercmp and Fn timespeccmp macros compare Fa a to Fa b using the comparison operator given in Fa CMP . The result of the comparison is returned.

SEE ALSO

timeval(3bsd)

HISTORY

The Fn timeradd family of macros first appeared in Nx 1.1 . These were later ported to Fx 2.2.6 . The Fn timespec family of macros first appeared in Nx 1.2 .