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 alarm(2)							    alarm(2)




 NAME
      alarm - set a process's alarm clock

 SYNOPSIS
      #include <&lt&lt&lt;unistd.h>&gt&gt&gt;

      unsigned int alarm(unsigned int sec);

 DESCRIPTION
      alarm() instructs the alarm clock of the calling process to send the
      signal SIGALRM to the calling process after the number of real-time
      seconds specified by sec have elapsed; see signal(5).  Specific
      implementations might place limitations on the maximum supported alarm
      time.  The constant MAX_ALARM defined in <sys/param.h> specifies the
      implementation-specific maximum.	Whenever sec is greater that this
      maximum, it is silently rounded down to it.  On all implementations,
      MAX_ALARM is guaranteed to be at least 31 days (in seconds).

      Alarm requests are not stacked; successive calls reset the alarm clock
      of the calling process.

      If sec is 0, any previously made alarm request is canceled.

      Alarms are not inherited by a child process across a fork(), but are
      inherited across an exec().

      On systems that support the getitimer() and setitimer() system calls,
      the timer mechanism used by alarm() is the same as that used by
      ITIMER_REAL. Thus successive calls to alarm(), getitimer(), and
      setitimer() set and return the state of a single timer.  In addition,
      alarm() sets the timer interval to zero.

 RETURN VALUE
      alarm() returns the amount of time previously remaining in the alarm
      clock of the calling process.

 WARNINGS
      In some implementations, error bounds for alarm are -1, +0 seconds
      (for the posting of the alarm, not the restart of the process).  Thus
      a delay of 1 second can return immediately.  The setitimer() routine
      can be used to create a more precise delay.

 SEE ALSO
      sleep(1), exec(2), getitimer(2), pause(2), signal(5), sleep(3C).

 STANDARDS CONFORMANCE
      alarm(): AES, SVID2, SVID3, XPG2, XPG3, XPG4, FIPS 151-2, POSIX.1







 Hewlett-Packard Company	    - 1 -   HP-UX Release 11i: November 2000