Utility for computing entropy of files. Just point at some, and it will return entropy value in range [0; 1].
$ entropy /etc/*
[OK] /etc/afpovertcp.cfg => entropy: 0.59891, bytes: 515
[OK] /etc/aliases => entropy: 0.53517, bytes: 10086
[OK] /etc/asl.conf => entropy: 0.60119, bytes: 1051
...