sys_time.h

<sys/time.h>(P)						      <sys/time.h>(P)



NAME
       sys/time.h - time types

SYNOPSIS
       #include <sys/time.h>

DESCRIPTION
       The  <sys/time.h>  header  shall	 define	 the  timeval  structure that
       includes at least the following members:


	      time_t	     tv_sec	 Seconds.
	      suseconds_t    tv_usec	 Microseconds.

       The <sys/time.h> header shall  define  the  itimerval  structure	 that
       includes at least the following members:


	      struct timeval it_interval Timer interval.
	      struct timeval it_value	 Current value.

       The  time_t  and	 suseconds_t  types  shall be defined as described in
       <sys/types.h> .

       The fd_set type shall be defined as described in <sys/select.h> .

       The <sys/time.h> header shall define  the  following  values  for  the
       which argument of getitimer() and setitimer():

       ITIMER_REAL
	      Decrements in real time.

       ITIMER_VIRTUAL
	      Decrements in process virtual time.

       ITIMER_PROF
	      Decrements  both in process virtual time and when the system is
	      running on behalf of the process.


       The following shall  be	defined	 as  described	in  <sys/select.h>  :
       FD_CLR() FD_ISSET() FD_SET() FD_ZERO() FD_SETSIZE

       The  following  shall be declared as functions and may also be defined
       as macros. Function prototypes shall be provided.


	      int   getitimer(int, struct itimerval *);
	      int   gettimeofday(struct timeval *restrict, void *restrict);
	      int   select(int, fd_set *restrict, fd_set *restrict, fd_set *restrict,
			struct timeval *restrict);
	      int   setitimer(int, const struct itimerval *restrict,
			struct itimerval *restrict);
	      int   utimes(const char *, const struct timeval [2]); (LEGACY )

       Inclusion of the <sys/time.h> header may make visible all symbols from
       the <sys/select.h> header.

       The following sections are informative.

APPLICATION USAGE
       None.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       <sys/select.h>  ,  <sys/types.h>	 ,  the	 System	 Interfaces volume of
       IEEE Std 1003.1-2001,	getitimer(),	gettimeofday(),	    select(),
       setitimer()

COPYRIGHT
       Portions	 of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2003 Edition, Standard for Information  Technol-
       ogy  --	Portable  Operating  System Interface (POSIX), The Open Group
       Base Specifications Issue 6, Copyright (C) 2001-2003 by the  Institute
       of  Electrical  and  Electronics Engineers, Inc and The Open Group. In
       the event of any discrepancy between this  version  and	the  original
       IEEE and The Open Group Standard, the original IEEE and The Open Group
       Standard is  the	 referee  document.  The  original  Standard  can  be
       obtained online at http://www.opengroup.org/unix/online.html .



POSIX				     2003		      <sys/time.h>(P)