Testing the compatibility of gpg and bouncy-gpg
For bouncy-gpg I needed to assert compatibility with gnupg. This means a lot of shelling out gpg.
Driving an external program from java and parsing its output is seldom needed. When it is needed, in often means: no stable API (changes in command output), configuration files, sporadic errors, and orchestrating parallel execution. To test the compatibility with gpg I needed to drive the GnuPG executable.