How to calculate a hash for a string (url) in bash for wget caching
Sounds like you want the md5sum system utility.
URLMD5=`/bin/echo $URL | /usr/bin/md5sum | /bin/cut -f1 -d" "`
If you want to only create the hash on the filename, you can get that quickly with sed:
FILENAME=`echo $URL | /bin/sed -e 's#.*/##'`
URLMD5=`/bin/echo $FILENAME | /usr/bin/md5sum | /bin/cut -f1 -d" "`
Note that, depending on your distribution, the path to cut may be /usr/bin/cut.
Other options on my Ubuntu (Precise) box:
echo -n $STRING | sha512sumecho -n $STRING | sha256sumecho -n $STRING | sha224sumecho -n $STRING | sha384sumecho -n $STRING | sha1sumecho -n $STRING | shasum
Other options on my Mac:
echo -n $STRING | shasum -a 512echo -n $STRING | shasum -a 256- etc.