Upsh stands for Unix to Prolog shell. It is a Prolog program which can be used to run Prolog programs from the command line or as scripts. It runs on three prolog engines: SICStus, SWI and Yap without changes to the source code.

With version 2.0.*, Upsh has all the features I had envisaged and many which I just thought of, on the way. It is also fairly stable, and runs well on all three supported engines. It is thus unlikely there will be any major releases in the future. I will of course fix any bugs reported or add features that are interesting. For reporting a bug or asking for a feature contact me on

If you use Upsh for a while I would appreciate an email with the kind of scripts you using it with.