freebsd man page for timercmp

TIMERADD(3)						   BSD Library Functions Manual 					       TIMERADD(3)

NAME
     timeradd, timersub, timerclear, timerisset, timercmp -- operations on timevals

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);

DESCRIPTION
     These macros are provided for manipulating timeval structures for use with the gettimeofday(2) and settimeofday(2) calls.	The structure is
     defined in <sys/time.h> as:

     struct timeval {
	     long    tv_sec;	     /* seconds since Jan. 1, 1970 */
	     long    tv_usec;	     /* and microseconds */
     };

     timeradd() adds the time information stored in a to b and stores the resulting timeval in res.  The results are simplified such that the
     value of res->tv_usec is always less than 1,000,000 (1 second).

     timersub() subtracts the time information stored in b from a and stores the resulting timeval in res.

     timerclear() initializes tvp to midnight (0 hour) January 1st, 1970 (the Epoch).

     timerisset() returns true if tvp is set to any time value other than the Epoch.

     timercmp() compares a to b using the comparison operator given in CMP, and returns the result of that comparison.

SEE ALSO
     gettimeofday(2)

HISTORY
     The timeradd() family of macros were imported from NetBSD 1.1, and appeared in FreeBSD 2.2.6.

BSD
								  August 11, 1999							       BSD