summaryrefslogtreecommitdiff
path: root/src/lib/libc/stdlib/rand.3
diff options
context:
space:
mode:
Diffstat (limited to 'src/lib/libc/stdlib/rand.3')
-rw-r--r--src/lib/libc/stdlib/rand.3105
1 files changed, 105 insertions, 0 deletions
diff --git a/src/lib/libc/stdlib/rand.3 b/src/lib/libc/stdlib/rand.3
new file mode 100644
index 0000000000..75395976f8
--- /dev/null
+++ b/src/lib/libc/stdlib/rand.3
@@ -0,0 +1,105 @@
1.\" Copyright (c) 1990, 1991 The Regents of the University of California.
2.\" All rights reserved.
3.\"
4.\" This code is derived from software contributed to Berkeley by
5.\" the American National Standards Committee X3, on Information
6.\" Processing Systems.
7.\"
8.\" Redistribution and use in source and binary forms, with or without
9.\" modification, are permitted provided that the following conditions
10.\" are met:
11.\" 1. Redistributions of source code must retain the above copyright
12.\" notice, this list of conditions and the following disclaimer.
13.\" 2. Redistributions in binary form must reproduce the above copyright
14.\" notice, this list of conditions and the following disclaimer in the
15.\" documentation and/or other materials provided with the distribution.
16.\" 3. 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.\" $OpenBSD: rand.3,v 1.15 2014/04/07 17:57:56 schwarze Exp $
33.\"
34.Dd $Mdocdate: April 7 2014 $
35.Dt RAND 3
36.Os
37.Sh NAME
38.Nm rand ,
39.Nm rand_r ,
40.Nm srand
41.Nd bad random number generator
42.Sh SYNOPSIS
43.In stdlib.h
44.Ft void
45.Fn srand "unsigned int seed"
46.Ft int
47.Fn rand void
48.Ft int
49.Fn rand_r "unsigned int *seed"
50.Sh DESCRIPTION
51.Bf -symbolic
52These interfaces are obsoleted by
53.Xr random 3 .
54.Ef
55.Pp
56The
57.Fn rand
58function computes a sequence of pseudo-random integers in the range
59of 0 to
60.Dv RAND_MAX
61(as defined by the header file
62.In stdlib.h ) .
63.Pp
64The
65.Fn srand
66function sets its argument as the seed for a new sequence of
67pseudo-random numbers to be returned by
68.Fn rand .
69These sequences are repeatable by calling
70.Fn srand
71with the same seed value.
72.Pp
73If no seed value is provided, the functions are automatically
74seeded with a value of 1.
75.Pp
76The
77.Fn rand_r
78is a thread-safe version of
79.Fn rand .
80Storage for the seed must be provided through the
81.Fa seed
82argument, and needs to have been initialized by the caller.
83.Sh SEE ALSO
84.Xr arc4random 3 ,
85.Xr rand48 3 ,
86.Xr random 3
87.Sh STANDARDS
88The
89.Fn rand
90and
91.Fn srand
92functions conform to
93.St -ansiC .
94.Pp
95The
96.Fn rand_r
97function conforms to
98.St -p1003.1-2008 .
99.Sh HISTORY
100The functions
101.Fn rand
102and
103.Fn srand
104first appeared in
105.At v3 .