Make UUID shorter (Hex to ASCII conversion)

In my web application one model uses identifier that was generated by some UUID tool. As I want that identifier to be part of the URL I am investigating methods to shorten that UUID string. 开发者_运维百科As it is currently is in hexadecimal format I thought about converting it to ASCII somehow. As it should afterwards only contain normal characters and number ([\d\w]+) the normal hex to ASCII conversion doesn't seem to work (ugly characters). Do you know of some nice algorithm or tool (Ruby) to do that?

A UUID is a 128-bit binary number, in the end. If you represent it as 16 unencoded bytes, there's no way to avoid "ugly characters". What you probably want to do is decode it from hex and then encode it using base64. Note that base64 encoding uses the characters + / = as well as A-Za-z0-9, you'll want to do a little postprocessing (I suggest s/+/-/g; s/\//_/g; s/==$// -- a base64ed UUID will always end with two equals signs)