random - random lines from a file or random numbers
random [-er] [denominator]
random reads lines from the standard input and copies them to the
standard output with a probability of 1/denominator. The default value
for denominator is 2.
The options are as follows:
-e If the -e option is specified, random does not read or write
anything, and simply exits with a random exit value of 0 to
-r The -r option guarantees that the output is unbuffered.