Loading...
stdlib/random.3 Libc-262.3.2 Libc-583
--- Libc/Libc-262.3.2/stdlib/random.3
+++ Libc/Libc-583/stdlib/random.3
@@ -30,38 +30,51 @@
 .\" SUCH DAMAGE.
 .\"
 .\"     @(#)random.3	8.1 (Berkeley) 6/4/93
-.\" $FreeBSD: src/lib/libc/stdlib/random.3,v 1.17 2001/09/07 14:46:36 asmodai Exp $
+.\" $FreeBSD: src/lib/libc/stdlib/random.3,v 1.20 2004/07/02 23:52:12 ru Exp $
 .\"
 .Dd June 4, 1993
 .Dt RANDOM 3
 .Os
 .Sh NAME
+.Nm initstate ,
 .Nm random ,
+.Nm setstate ,
 .Nm srandom ,
-.Nm srandomdev ,
-.Nm initstate ,
-.Nm setstate
+.Nm srandomdev
 .Nd better random number generator; routines for changing generators
 .Sh LIBRARY
 .Lb libc
 .Sh SYNOPSIS
 .In stdlib.h
+.Ft char *
+.Fo initstate
+.Fa "unsigned seed"
+.Fa "char *state"
+.Fa "size_t size"
+.Fc
 .Ft long
-.Fn random void
+.Fo random
+.Fa void
+.Fc
+.Ft char *
+.Fo setstate
+.Fa "const char *state"
+.Fc
 .Ft void
-.Fn srandom "unsigned long seed"
+.Fo srandom
+.Fa "unsigned seed"
+.Fc
 .Ft void
-.Fn srandomdev void
-.Ft char *
-.Fn initstate "unsigned long seed" "char *state" "long n"
-.Ft char *
-.Fn setstate "char *state"
+.Fo srandomdev
+.Fa void
+.Fc
 .Sh DESCRIPTION
 The
 .Fn random
 function
-uses a non-linear additive feedback random number generator employing a
-default table of size 31 long integers to return successive pseudo-random
+uses a non-linear, additive feedback, random number generator, employing a
+default table of size 31 long integers.
+It returns successive pseudo-random
 numbers in the range from 0 to
 .if t 2\u\s731\s10\d\(mi1.
 .if n (2**31)\(mi1.
@@ -81,9 +94,11 @@
 The difference is that
 .Xr rand 3
 produces a much less random sequence \(em in fact, the low dozen bits
-generated by rand go through a cyclic pattern.  All the bits generated by
-.Fn random
-are usable.  For example,
+generated by rand go through a cyclic pattern.
+All of the bits generated by
+.Fn random
+are usable.
+For example,
 .Sq Li random()&01
 will produce a random binary
 value.
@@ -100,7 +115,7 @@
 .Pp
 The
 .Fn srandomdev
-routine initialize a state array using
+routine initializes a state array, using the
 .Xr random 4
 random number device which returns good random numbers,
 suitable for cryptographic use.
@@ -115,15 +130,17 @@
 The
 .Fn initstate
 routine allows a state array, passed in as an argument, to be initialized
-for future use.  The size of the state array (in bytes) is used by
+for future use.
+The size of the state array (in bytes) is used by
 .Fn initstate
 to decide how sophisticated a random number generator it should use \(em the
 more state, the better the random numbers will be.
 (Current "optimal" values for the amount of state information are
 8, 32, 64, 128, and 256 bytes; other amounts will be rounded down to
-the nearest known amount.  Using less than 8 bytes will cause an error.)
+the nearest known amount.
+Using less than 8 bytes will cause an error.)
 The seed for the initialization (which specifies a starting point for
-the random number sequence, and provides for restarting at the same
+the random number sequence and provides for restarting at the same
 point) is also an argument.
 The
 .Fn initstate
@@ -162,7 +179,7 @@
 With 256 bytes of state information, the period of the random number
 generator is greater than
 .if t 2\u\s769\s10\d,
-.if n 2**69
+.if n 2**69 ,
 which should be sufficient for most purposes.
 .Sh AUTHORS
 .An Earl T. Cohen
@@ -173,10 +190,36 @@
 .Fn setstate
 detects that the state information has been garbled, error
 messages are printed on the standard error output.
+.Sh LEGACY SYNOPSIS
+.Fd #include <stdlib.h>
+.Pp
+.Ft char *
+.br
+.Fo initstate
+.Fa "unsigned long seed"
+.Fa "char *state"
+.Fa "long size"
+.Fc ;
+.Pp
+.Ft char *
+.br
+.Fo setstate
+.Fa "char *state"
+.Fc ;
+.Pp
+.Ft void
+.br
+.Fo srandom
+.Fa "unsigned long seed"
+.Fc ;
+.Pp
+The type of each parameter is different in the legacy version.
 .Sh SEE ALSO
+.Xr arc4random 3 ,
 .Xr rand 3 ,
 .Xr srand 3 ,
-.Xr random 4
+.Xr random 4 ,
+.Xr compat 5
 .Sh HISTORY
 These
 functions appeared in
@@ -189,3 +232,6 @@
 random sequence did not vary much with the seed.
 The current implementation employs a better pseudo-random number
 generator for the initial state calculation.
+.Pp
+Applications requiring cryptographic quality randomness should use
+.Xr arc4random 3 .