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TIMERADD(3) FreeBSD Library Functions Manual TIMERADD(3)
NAME
timeradd, timersub, timerclear, timerisset, timercmp, timespecadd,
timespecsub, timespecclear, timespecisset, timespeccmp - operations on
timevals and timespecs
SYNOPSIS
#include <sys/time.h>
void
timeradd(struct timeval *a, struct timeval *b, struct timeval *res);
void
timersub(struct timeval *a, struct timeval *b, struct timeval *res);
void
timerclear(struct timeval *tvp);
int
timerisset(struct timeval *tvp);
int
timercmp(struct timeval *a, struct timeval *b, CMP);
void
timespecadd(struct timespec *a, struct timespec *b,
struct timespec *res);
void
timespecsub(struct timespec *a, struct timespec *b,
struct timespec *res);
void
timespecclear(struct timespec *ts);
int
timespecisset(struct timespec *ts);
int
timespeccmp(struct timespec *a, struct timespec *b, CMP);
DESCRIPTION
These macros are provided for manipulating timeval and timespec
structures for use with the clock_gettime(2), clock_settime(2),
gettimeofday(2) and settimeofday(2) calls. The timeval structure is
defined in <sys/time.h> as:
struct timeval {
long tv_sec; /* seconds since Jan. 1, 1970 */
long tv_usec; /* and microseconds */
};
And the timespec structure is defined in <time.h> as:
struct timespec {
time_t tv_sec; /* seconds */
long tv_nsec; /* and nanoseconds */
};
timerclear() and timespecclear() initialize their argument to midnight (0
hour) January 1st, 1970 (the Epoch).
timerisset() and timespecisset() return true if their argument is set to
any time value other than the Epoch.
timercmp() and timespeccmp() compare a to b using the comparison operator
given in CMP, and return the result of that comparison.
SEE ALSO
clock_gettime(2), gettimeofday(2)
HISTORY
The timeradd() family of macros were imported from NetBSD 1.1, and
appeared in FreeBSD 2.2.6. The timespecadd() family of macros were
imported from NetBSD 1.3 into FreeBSD 3.0, though they were not exposed
to userland until FreeBSD 12.0.
FreeBSD 14.0-RELEASE-p11 July 30, 2018 FreeBSD 14.0-RELEASE-p11