In many astronomy programs, we have to put up with the PFILES convention, where arguments are given like so

    mytool infile=foo.fits outfile=bar.fits

Some parameters need to be given (and will be prompted for if not given), and some get a default if they are omitted. The extra tricky part is that the parameters and their defaults are read from .par files in a path. There are the default ones for the tool, and a user-specific parameter file which can be modified using the "pset" program (or read with "pget"). A tool when run will also modify the par file to update various parameters with the ones given on the command line.

Unfortunately, there is no form of locking on these par files, so one has to mess around with the path settings (to make per-process paths), or use some form of locking, to ensure they don't get corrupted if multiple processes are run at once.