Rename files to md5 sum + extension (BASH)

This might work for you:

# mkdir temp && cd temp && touch file.{a..e}
# ls
file.a  file.b  file.c  file.d  file.e
# md5sum * | sed -e 's/\([^ ]*\) \(.*\(\..*\)\)$/mv -v \2 \1\3/' | sh
`file.a' -> `d41d8cd98f00b204e9800998ecf8427e.a'
`file.b' -> `d41d8cd98f00b204e9800998ecf8427e.b'
`file.c' -> `d41d8cd98f00b204e9800998ecf8427e.c'
`file.d' -> `d41d8cd98f00b204e9800998ecf8427e.d'
`file.e' -> `d41d8cd98f00b204e9800998ecf8427e.e'

Or GNU sed can do it even shorter:
# md5sum * | sed -e 's/\([^ ]*\) \(.*\(\..*\)\)$/mv -v \2 \1\3/e'

The Apple/OSX version is: md5 * | sed -e 's/MD5 (\([^.]*\)\(.[^)]*\)) = \(.*\)$/mv -v "\1\2" \3\2/' | sh – fnl

http://stackoverflow.com/questions/8201729/rename-files-to-md5-sum-extension-bash