NAME

       memshuffle - make an array be in random order

SYNOPSIS

       #include <publib.h>
       void *memshuffle(void *block, size_t elsize, size_t elnum);

DESCRIPTION

       memshuffle  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 VALUE

       memshuffle returns its first argument.

EXAMPLE

       To shuffle an integer array one might do the following.

            int array[4] = { 1, 2, 3, 4 };

            memshuffle(array, sizeof(array[0]), 4);

BUGS

       On  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 ALSO

       publib(3), memrev(3), rand(3), srand(3)

AUTHOR

       Lars Wirzenius (lars.wirzenius@helsinki.fi)