alarm(poll.html) - phpMan

ALARM(2)                   Linux Programmer's Manual                  ALARM(2)

NAME
       alarm - set an alarm clock for delivery of a signal
SYNOPSIS
       #include <unistd.h>
       unsigned int alarm(unsigned int seconds);
DESCRIPTION
       alarm()  arranges  for  a SIGALRM signal to be delivered to the calling
       process in seconds seconds.
       If seconds is zero, any pending alarm is canceled.
       In any event any previously set alarm() is canceled.
RETURN VALUE
       alarm() returns the number of seconds remaining  until  any  previously
       scheduled alarm was due to be delivered, or zero if there was no previ-
       ously scheduled alarm.
CONFORMING TO
       SVr4, POSIX.1-2001, 4.3BSD.
NOTES
       alarm() and setitimer(2) share the same timer; calls to one will inter-
       fere with use of the other.
       sleep(3)  may be implemented using SIGALRM; mixing calls to alarm() and
       sleep(3) is a bad idea.
       Scheduling delays can, as ever, cause the execution of the  process  to
       be delayed by an arbitrary amount of time.
SEE ALSO
       gettimeofday(2),  pause(2), select(2), setitimer(2), sigaction(2), sig-
       nal(2), sleep(3), 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                             2013-04-18                          ALARM(2)