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+.\" This manpage is Copyright (C) 1992 Drew Eckhardt;
+.\" and Copyright (C) 1993 Michael Haardt, Ian Jackson.
+.\"
+.\" SPDX-License-Identifier: Linux-man-pages-copyleft
+.\"
+.\" Modified Wed Jul 21 19:42:57 1993 by Rik Faith <faith@cs.unc.edu>
+.\" Modified Sun Jul 21 21:25:26 1996 by Andries Brouwer <aeb@cwi.nl>
+.\" Modified Wed Nov 6 03:46:05 1996 by Eric S. Raymond <esr@thyrsus.com>
+.\"
+.TH alarm 2 2024-05-02 "Linux man-pages (unreleased)"
+.SH NAME
+alarm \- set an alarm clock for delivery of a signal
+.SH LIBRARY
+Standard C library
+.RI ( libc ", " \-lc )
+.SH SYNOPSIS
+.nf
+.B #include <unistd.h>
+.P
+.BI "unsigned int alarm(unsigned int " seconds );
+.fi
+.SH DESCRIPTION
+.BR alarm ()
+arranges for a
+.B SIGALRM
+signal to be delivered to the calling process in
+.I seconds
+seconds.
+.P
+If
+.I seconds
+is zero, any pending alarm is canceled.
+.P
+In any event any previously set
+.BR alarm ()
+is canceled.
+.SH RETURN VALUE
+.BR 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.
+.SH STANDARDS
+POSIX.1-2008.
+.SH HISTORY
+POSIX.1-2001, SVr4, 4.3BSD.
+.SH NOTES
+.BR alarm ()
+and
+.BR setitimer (2)
+share the same timer; calls to one will interfere with use of the
+other.
+.P
+Alarms created by
+.BR alarm ()
+are preserved across
+.BR execve (2)
+and are not inherited by children created via
+.BR fork (2).
+.P
+.BR sleep (3)
+may be implemented using
+.BR SIGALRM ;
+mixing calls to
+.BR alarm ()
+and
+.BR sleep (3)
+is a bad idea.
+.P
+Scheduling delays can, as ever, cause the execution of the process to
+be delayed by an arbitrary amount of time.
+.SH SEE ALSO
+.BR gettimeofday (2),
+.BR pause (2),
+.BR select (2),
+.BR setitimer (2),
+.BR sigaction (2),
+.BR signal (2),
+.BR timer_create (2),
+.BR timerfd_create (2),
+.BR sleep (3),
+.BR time (7)