I post this a lot - whenever you have a file do something funky like that, do 'file
filename'. It's great. You get stuff like:
openssl-0.9.7c-i486-2.tgz: gzip compressed data, was "openssl-0.9.7c-i486-2.tar", from Unix, max compression
openssl-0.9.7c-i486-2.tgz.asc: PGP armored text
openssl-0.9.7c-i486-2.txt: ASCII English text
Tells you exactly what it is in many cases which lets you know exactly what to do with it.