xref: /freebsd/lib/libc/gen/alarm.3 (revision ef5d438ed4bc17ad7ece3e40fe4d1f9baf3aadf7)
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32.\"     @(#)alarm.3	8.2 (Berkeley) 4/19/94
33.\"
34.Dd April 19, 1994
35.Dt ALARM 3
36.Os BSD 4
37.Sh NAME
38.Nm alarm
39.Nd set signal timer alarm
40.Sh SYNOPSIS
41.Fd #include <unistd.h>
42.Ft u_int
43.Fn alarm "u_int seconds"
44.Sh DESCRIPTION
45.Bf -symbolic
46This interface is made obsolete by setitimer(2).
47.Ef
48.Pp
49The
50.Fn alarm
51function
52waits a count of
53.Ar seconds
54before asserting the terminating signal
55.Dv SIGALRM .
56When the signal has successfully been caught,
57.Fn alarm
58returns the amount of time left on the clock.
59The maximum number of
60.Ar seconds
61allowed
62is 2147483647.
63.Pp
64If an alarm has been set with
65.Fn alarm ,
66another call to
67.Fn alarm
68will supersede the prior call.
69The request
70.Fn alarm "0"
71voids the current
72alarm.
73.Sh SEE ALSO
74.Xr sigaction 2 ,
75.Xr setitimer 2 ,
76.Xr sigpause 2 ,
77.Xr sigvec 2 ,
78.Xr signal 3 ,
79.Xr sleep 3 ,
80.Xr ualarm 3 ,
81.Xr usleep 3
82.Sh HISTORY
83An
84.Fn alarm
85function appeared in
86.At v7 .
87