[unix-history] / usr / man / man2 / alarm.2

.TH ALARM 2 
.SH NAME
alarm \- schedule signal after specified time
.SH SYNOPSIS
.B alarm(seconds)
.br
.B unsigned seconds;
.SH DESCRIPTION
.I Alarm
causes signal SIGALRM, see
.IR signal (2),
to be sent to the invoking process
in a number of seconds given by the argument.
Unless caught or ignored, the signal terminates the process.
.PP
Alarm requests are not stacked;
successive calls reset the alarm clock.
If the argument is 0, any alarm request is cancelled.
Because the clock has a 1-second resolution,
the signal may occur up to one second early;
because of scheduling delays,
resumption of execution of when the signal is
caught may be delayed an arbitrary amount.
The longest specifiable delay time is 2147483647 seconds.
.PP
The return value is the amount of time
previously remaining in the alarm clock.
.SH "SEE ALSO"
pause(2), signal(2), sleep(3)
.SH "ASSEMBLER (PDP-11)"
(alarm = 27.)
.br
(seconds in r0)
.br
.B sys alarm
.br
(previous amount in r0)
Commit	Line	Data
e6817382 BJ	1	.TH ALARM 2
	2	.SH NAME
	3	alarm \- schedule signal after specified time
	4	.SH SYNOPSIS
	5	.B alarm(seconds)
	6	.br
	7	.B unsigned seconds;
	8	.SH DESCRIPTION
	9	.I Alarm
	10	causes signal SIGALRM, see
	11	.IR signal (2),
	12	to be sent to the invoking process
	13	in a number of seconds given by the argument.
	14	Unless caught or ignored, the signal terminates the process.
	15	.PP
	16	Alarm requests are not stacked;
	17	successive calls reset the alarm clock.
	18	If the argument is 0, any alarm request is cancelled.
	19	Because the clock has a 1-second resolution,
	20	the signal may occur up to one second early;
	21	because of scheduling delays,
	22	resumption of execution of when the signal is
	23	caught may be delayed an arbitrary amount.
	24	The longest specifiable delay time is 2147483647 seconds.
	25	.PP
	26	The return value is the amount of time
	27	previously remaining in the alarm clock.
	28	.SH "SEE ALSO"
	29	pause(2), signal(2), sleep(3)
	30	.SH "ASSEMBLER (PDP-11)"
	31	(alarm = 27.)
	32	.br
	33	(seconds in r0)
	34	.br
	35	.B sys alarm
	36	.br
	37	(previous amount in r0)