TIMERADD(3) | Library Functions Manual | TIMERADD(3)

# NAME

`timeradd` —
operations on time structure

# 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 *tv);

int
`timerisset`(struct timeval *tv);

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 the timeval and timespec structures described in timeval(3).

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

The `timersub`() and `timespecsub`() macros subtract the time information stored in b from a and store the resulting structure in res.

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

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

# SEE ALSO

timeval(3)

# HISTORY

The `timeradd`() family of macros first appeared in NetBSD 1.1. These were later ported to FreeBSD 2.2.6. The `timespec`() family of macros first appeared in NetBSD 1.2.

June 7, 2010 | NetBSD 9.0