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1 | .\" Copyright (c) 1986, 1991 Regents of the University of California. |
2 | .\" All rights reserved. | |
3 | .\" | |
4 | .\" Redistribution and use in source and binary forms, with or without | |
5 | .\" modification, are permitted provided that the following conditions | |
6 | .\" are met: | |
7 | .\" 1. Redistributions of source code must retain the above copyright | |
8 | .\" notice, this list of conditions and the following disclaimer. | |
9 | .\" 2. Redistributions in binary form must reproduce the above copyright | |
10 | .\" notice, this list of conditions and the following disclaimer in the | |
11 | .\" documentation and/or other materials provided with the distribution. | |
12 | .\" 3. All advertising materials mentioning features or use of this software | |
13 | .\" must display the following acknowledgement: | |
14 | .\" This product includes software developed by the University of | |
15 | .\" California, Berkeley and its contributors. | |
16 | .\" 4. Neither the name of the University nor the names of its contributors | |
17 | .\" may be used to endorse or promote products derived from this software | |
18 | .\" without specific prior written permission. | |
19 | .\" | |
20 | .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
21 | .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
22 | .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
23 | .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
24 | .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
25 | .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
26 | .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
27 | .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
28 | .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
29 | .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
30 | .\" SUCH DAMAGE. | |
31 | .\" | |
32 | .\" @(#)ualarm.3 6.5 (Berkeley) 4/19/91 | |
33 | .\" | |
34 | .Dd April 19, 1991 | |
35 | .Dt UALARM 3 | |
36 | .Os BSD 4.3 | |
37 | .Sh NAME | |
38 | .Nm ualarm | |
39 | .Nd schedule signal after specified time | |
40 | .Sh SYNOPSIS | |
41 | .Fd #include <unistd.h> | |
42 | .Ft u_int | |
43 | .Fn ualarm "u_int microseconds" "u_int interval" | |
44 | .Sh DESCRIPTION | |
45 | .Bf -symbolic | |
46 | This is a simplified interface to setitimer(2). | |
47 | .Ef | |
48 | .Pp | |
49 | The | |
50 | .Fn ualarm | |
51 | function | |
52 | waits a count of | |
53 | .Ar microseconds | |
54 | before asserting the terminating signal | |
55 | .Dv SIGALRM . | |
56 | System activity or time used in processing the call may cause a slight | |
57 | delay. | |
58 | .Pp | |
59 | If the | |
60 | .Fa interval | |
61 | argument is non-zero, the | |
62 | .Dv SIGALRM | |
63 | signal will be sent | |
64 | to the process every | |
65 | .Fa interval | |
66 | microseconds after the timer expires (e.g. after | |
67 | .Fa value | |
68 | microseconds have passed). | |
69 | .Sh RETURN VALUES | |
70 | When the signal has successfully been caught, | |
71 | .Fn alarm | |
72 | returns the amount of time left on the clock. | |
73 | The maximum mumber of | |
74 | .Ar microseconds | |
75 | allowed | |
76 | is 2147483647. | |
77 | .Sh SEE ALSO | |
78 | .Xr getitimer 2 , | |
79 | .Xr setitimer 2 , | |
80 | .Xr sigpause 2 , | |
81 | .Xr sigvec 2 , | |
82 | .Xr signal 3 , | |
83 | .Xr sleep 3 , | |
84 | .Xr alarm 3 , | |
85 | .Xr usleep 3 | |
86 | .Sh HISTORY | |
87 | The | |
88 | .Fn ualarm | |
89 | function appeared in | |
90 | .Bx 4.3 . |