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diff --git a/man3/random.3 b/man3/random.3 deleted file mode 100644 index 94f146a13..000000000 --- a/man3/random.3 +++ /dev/null @@ -1,196 +0,0 @@ -'\" t -.\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) -.\" -.\" SPDX-License-Identifier: Linux-man-pages-copyleft -.\" -.\" References consulted: -.\" Linux libc source code -.\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) -.\" 386BSD man pages -.\" Modified Sun Mar 28 00:25:51 1993, David Metcalfe -.\" Modified Sat Jul 24 18:13:39 1993 by Rik Faith (faith@cs.unc.edu) -.\" Modified Sun Aug 20 21:47:07 2000, aeb -.\" -.TH random 3 (date) "Linux man-pages (unreleased)" -.SH NAME -random, srandom, initstate, setstate \- random number generator -.SH LIBRARY -Standard C library -.RI ( libc ", " \-lc ) -.SH SYNOPSIS -.nf -.B #include <stdlib.h> -.PP -.B long random(void); -.BI "void srandom(unsigned int " seed ); -.PP -.BI "char *initstate(unsigned int " seed ", char " state [. n "], size_t " n ); -.BI "char *setstate(char *" state ); -.fi -.PP -.RS -4 -Feature Test Macro Requirements for glibc (see -.BR feature_test_macros (7)): -.RE -.PP -.BR random (), -.BR srandom (), -.BR initstate (), -.BR setstate (): -.nf - _XOPEN_SOURCE >= 500 -.\" || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED - || /* glibc >= 2.19: */ _DEFAULT_SOURCE - || /* glibc <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE -.fi -.SH DESCRIPTION -The -.BR random () -function uses a nonlinear additive feedback random -number generator employing a default table of size 31 long integers to -return successive pseudo-random numbers in -the range from 0 to 2\[ha]31\ \-\ 1. -The period of this random number generator is very large, approximately -.IR "16\ *\ ((2\[ha]31)\ \-\ 1)" . -.PP -The -.BR srandom () -function sets its argument as the seed for a new -sequence of pseudo-random integers to be returned by -.BR random (). -These sequences are repeatable by calling -.BR srandom () -with the same -seed value. -If no seed value is provided, the -.BR random () -function -is automatically seeded with a value of 1. -.PP -The -.BR initstate () -function allows a state array \fIstate\fP to -be initialized for use by -.BR random (). -The size of the state array -\fIn\fP is used by -.BR initstate () -to decide how sophisticated a -random number generator it should use\[em]the larger the state array, -the better the random numbers will be. -Current "optimal" values for the size of the state array \fIn\fP are -8, 32, 64, 128, and 256 bytes; other amounts will be rounded down to -the nearest known amount. -Using less than 8 bytes results in an error. -\fIseed\fP is the seed for the -initialization, which specifies a starting point for the random number -sequence, and provides for restarting at the same point. -.PP -The -.BR setstate () -function changes the state array used by the -.BR random () -function. -The state array \fIstate\fP is used for -random number generation until the next call to -.BR initstate () -or -.BR setstate (). -\fIstate\fP must first have been initialized -using -.BR initstate () -or be the result of a previous call of -.BR setstate (). -.SH RETURN VALUE -The -.BR random () -function returns a value between 0 and -.IR "(2\[ha]31)\ \-\ 1" . -The -.BR srandom () -function returns no value. -.PP -The -.BR initstate () -function returns a pointer to the previous state array. -On failure, it returns NULL, and -.I errno -is set to indicate the error. -.PP -On success, -.BR setstate () -returns a pointer to the previous state array. -On failure, it returns NULL, and -.I errno -is set to indicate the error. -.SH ERRORS -.TP -.B EINVAL -The -.I state -argument given to -.BR setstate () -was NULL. -.TP -.B EINVAL -A state array of less than 8 bytes was specified to -.BR initstate (). -.SH ATTRIBUTES -For an explanation of the terms used in this section, see -.BR attributes (7). -.ad l -.nh -.TS -allbox; -lbx lb lb -l l l. -Interface Attribute Value -T{ -.BR random (), -.BR srandom (), -.BR initstate (), -.BR setstate () -T} Thread safety MT-Safe -.TE -.hy -.ad -.sp 1 -.SH STANDARDS -POSIX.1-2008. -.SH HISTORY -POSIX.1-2001, 4.3BSD. -.SH NOTES -Random-number generation is a complex topic. -.I Numerical Recipes in C: The Art of Scientific Computing -(William H.\& Press, Brian P.\& Flannery, Saul A.\& Teukolsky, -William T.\& Vetterling; New York: Cambridge University Press, 2007, 3rd ed.) -provides an excellent discussion of practical random-number generation -issues in Chapter 7 (Random Numbers). -.PP -For a more theoretical discussion which also covers many practical issues -in depth, see Chapter 3 (Random Numbers) in Donald E.\& Knuth's -.IR "The Art of Computer Programming" , -volume 2 (Seminumerical Algorithms), 2nd ed.; Reading, Massachusetts: -Addison-Wesley Publishing Company, 1981. -.SH CAVEATS -The -.BR random () -function should not be used in multithreaded programs -where reproducible behavior is required. -Use -.BR random_r (3) -for that purpose. -.SH BUGS -According to POSIX, -.BR initstate () -should return NULL on error. -In the glibc implementation, -.I errno -is (as specified) set on error, but the function does not return NULL. -.\" http://sourceware.org/bugzilla/show_bug.cgi?id=15380 -.SH SEE ALSO -.BR getrandom (2), -.BR drand48 (3), -.BR rand (3), -.BR random_r (3), -.BR srand (3) |