alarm — set an alarm clock for delivery of a signal
#include <unistd.h>
unsigned int
alarm( |
unsigned int seconds); |
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.
alarm() returns the number
of seconds remaining until any previously scheduled alarm was
due to be delivered, or zero if there was no previously
scheduled alarm.
alarm() and setitimer(2) share the same
timer; calls to one will interfere with use of the other.
Alarms created by alarm()
are preserved across execve(2) and are not
inherited by children created via fork(2).
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.
gettimeofday(2), pause(2), select(2), setitimer(2), sigaction(2), signal(2), timer_create(2), timerfd_create(2), sleep(3), time(7)
This page is part of release 4.16 of the Linux man-pages project. A
description of the project, information about reporting bugs,
and the latest version of this page, can be found at
https://www.kernel.org/doc/man−pages/.
|
This manpage is Copyright (C) 1992 Drew Eckhardt; and Copyright (C) 1993 Michael Haardt, Ian Jackson. %%%LICENSE_START(VERBATIM) Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Since the Linux kernel and libraries are constantly changing, this manual page may be incorrect or out-of-date. The author(s) assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein. The author(s) may not have taken the same level of care in the production of this manual, which is licensed free of charge, as they might when working professionally. Formatted or processed versions of this manual, if unaccompanied by the source, must acknowledge the copyright and authors of this work. %%%LICENSE_END Modified Wed Jul 21 19:42:57 1993 by Rik Faith <faithcs.unc.edu> Modified Sun Jul 21 21:25:26 1996 by Andries Brouwer <aebcwi.nl> Modified Wed Nov 6 03:46:05 1996 by Eric S. Raymond <esrthyrsus.com> |