The GNU Awk User's Guide
13.2.4 The Cliff Random Number Generator
The Cliff random number
generator(53)
is a very simple random number generator that "passes the noise sphere test
for randomness by showing no structure."
It is easily programmed, in less than 10 lines of awk
code:
 # cliff_rand.awk  generate Cliff random numbers
BEGIN { _cliff_seed = 0.1 }
function cliff_rand()
{
_cliff_seed = (100 * log(_cliff_seed)) % 1
if (_cliff_seed < 0)
_cliff_seed =  _cliff_seed
return _cliff_seed
}

This algorithm requires an initial "seed" of 0.1. Each new value
uses the current seed as input for the calculation.
If the builtin rand
function
(see section 9.1.2 Numeric Functions)
isn't random enough, you might try using this function instead.