The purpose of the (undocumented) startpar -f flag is to read from stdin and write whatever it finds to to stdout. That's pretty much all it does. And it keeps going until it runs out of input.
I'm not sure why it would do that or why someone would call startpar with that parameter since it doesn't seem to do anything useful. The program just keeps passing stdin to stdout until it reaches an end-of-input flag (like ctrl-d) or someone kills it. I don't even think startpar is running the given commands (sks and shellinabox) in the above situations as it exits after doing its input-to-output copying. So my suggestion is: looks like someone called startpar with -f, perhaps by accident in a script. And the -f flag should probably not have been used in that case. And the lingering startpar processes can be terminated. - Jesse (upstream dev)
