Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
TIMERADD(3)		   Linux Programmer's Manual		   TIMERADD(3)

NAME
       timeradd,  timersub,  timercmp, timerclear, timerisset -	timeval	opera-
       tions

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);

   Feature Test	Macro Requirements for glibc (see feature_test_macros(7)):

       All functions shown above: _BSD_SOURCE

DESCRIPTION
       The macros are provided to operate on timeval  structures,  defined  in
       _sys/time.h_ as:

	   struct timeval {
	       time_t	   tv_sec;     /* seconds */
	       suseconds_t tv_usec;    /* microseconds */
	   };

       timeradd()  adds	 the time values in a and b, and places	the sum	in the
       timeval pointed	to  by	res.   The  result  is	normalized  such  that
       res-_tv_usec has	a value	in the range 0 to 999,999.

       timersub()  subtracts the time value in b from the time value in	a, and
       places the result in the	timeval	pointed	to by res.  The	result is nor-
       malized such that res-_tv_usec has a value in the range 0 to 999,999.

       timerclear() zeros out the timeval structure pointed to by tvp, so that
       it represents the Epoch:	1970-01-01 00:00:00 +0000 (UTC).

       timerisset() returns true (nonzero) if  either  field  of  the  timeval
       structure pointed to by tvp contains a nonzero value.

       timercmp()  compares  the  timer	values in a and	b using	the comparison
       operator	CMP, and returns true (nonzero)	or false (0) depending on  the
       result  of  the comparison.  Some systems (but not Linux/glibc),	have a
       broken timercmp() implementation, in which CMP of _=, _=, and ==	do not
       work; portable applications can instead use

	   !timercmp(..., <)
	   !timercmp(..., >)
	   !timercmp(..., !=)

RETURN VALUE
       timerisset() and	timercmp() return true (nonzero) or false (0).

ERRORS
       No errors are defined.

CONFORMING TO
       Not in POSIX.1-2001.  Present on	most BSD derivatives.

SEE ALSO
       gettimeofday(2),	time(7)

COLOPHON
       This  page  is  part of release 3.53 of the Linux man-pages project.  A
       description of the project, and information about reporting  bugs,  can
       be found	at http://www.kernel.org/doc/man-pages/.

Linux				  2010-02-25			   TIMERADD(3)

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | CONFORMING TO | SEE ALSO | COLOPHON

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=timeradd&sektion=3&manpath=CentOS+7.1>

home | help