String to string compression algorithm?

Question

I'm looking for an algorithm that would compress some string to another string (i.e. without "\0" or special control characters), but I can't find anything on the internet. Is there such an algorithm? It doesn't have to be particularly efficient, just something basic.

Answer 1

Easy:

$ echo "Hello world" | gzip -c | base64
H4sIALnHeU4AA/NIzcnJVyjPL8pJ4QIA1eA5twwAAAA=

$ echo "H4sIALnHeU4AA/NIzcnJVyjPL8pJ4QIA1eA5twwAAAA=" | base64 -d | gzip -dc
Hello world

Note: looks like there is no compression, but for bigger data the compression ratio will be better :-)