Query: memshuffle
OS: debian
Section: 3pub
Format: Original Unix Latex Style Formatted with HTML and a Horizontal Scroll Bar
MEMSHUFFLE(3pub) C Programmer's Manual MEMSHUFFLE(3pub)NAMEmemshuffle - make an array be in random orderSYNOPSIS#include <publib.h> void *memshuffle(void *block, size_t elsize, size_t elnum);DESCRIPTIONmemshuffle will move around the elements of an array in a random fashion. It uses the standard library function rand(3) to get the pseudo- random numbers it needs. The caller must set a suitable seed with srand(3).RETURN VALUEmemshuffle returns its first argument.EXAMPLETo shuffle an integer array one might do the following. int array[4] = { 1, 2, 3, 4 }; memshuffle(array, sizeof(array[0]), 4);BUGSOn many systems rand(3) is not of very good quality. However, it is the only random number generator that can be assumed to exist. Making it possible for the caller to provide an alternate source of random numbers (e.g., via a function pointer) is perhaps too more trouble than its worth. A better way would be for everyone to fix their rand's.SEE ALSOpublib(3), memrev(3), rand(3), srand(3)AUTHORLars Wirzenius (lars.wirzenius@helsinki.fi) Publib C Programmer's Manual MEMSHUFFLE(3pub)