NAME
	  alarm, ualarm	- Sets or changes the timeout of interval
	  timers

     LIBRARY
	  Standard C Library (libc.a)

     SYNOPSIS
	  #include <unistd.h>

	  unsigned int alarm(
	      unsigned int seconds) ;

	  unsigned int ualarm(
	      unsigned int mseconds,
	      unsigned int interval) ;

     PARAMETERS
	  seconds   Specifies a	number of real-time seconds.

	  mseconds  Specifies a	number of real-time microseconds.

	  interval  Specifies the interval for repeating the timer.


     DESCRIPTION
	  The alarm() function is used to obtain notification of a
	  timeout after	the number of real-time	seconds	specified by
	  the seconds parameter	has elapsed.  At some time after
	  seconds seconds have elapsed,	a signal is delivered to the
	  process.  The	call sends a SIGALRM signal to the calling
	  process.  Each call resets the timer until the seconds
	  parameter is set to 0	(zero).	When the notification signal
	  is caught or ignored,	no action takes	place; otherwise the
	  calling process is terminated.  The alarm() function uses
	  the ITIMER_REAL interval timer.

	  The ualarm() function	is used	to obtain notification of a
	  timeout after	the number of real-time	microseconds specified
	  by the mseconds parameter has	elapsed.  When the interval
	  parameter is nonzero,	timeout	notification occurs after the
	  number of microseconds specified by the interval parameter
	  has been added to the	mseconds parameter.  When the notifi-
	  cation signal	is caught or ingnored, no action takes place;
	  otherwise the	calling	process	is terminated.	The ualarm()
	  function is the simplified interface to the setitimer()
	  function, and	uses the ITIMER_REAL interval timer.

     NOTES
	  The alarm() function is supported for	multi-threaded appli-
	  cations.  The	ualarm() function is not supported for multi-
	  ple threads.
	  Although the alarm() function	itself is reentrant, it	should
	  be noted that	just as	the second of two calls	from a single
	  thread to alarm() resets the timer, this is also true	if two
	  calls	are made from different	threads.


	  AES Support Level:
			 Full use


     RETURN VALUES
	  Upon successful completion, the number of seconds remaining
	  from the previous alarm() call is returned.  Otherwise, -1
	  is returned and errno	is set to indicate the error.

     ERRORS
	  If the alarm() function fails, errno may be set to the fol-
	  lowing value:


	  [EINVAL]  The	seconds	parameter specifies a negative value
		    or a value greater than 100,000,000.


     RELATED INFORMATION
	  Functions: gettimer(3)