I have looked at the problem of unneeded processes being started when using --pipe. https://savannah.gnu.org/bugs/?34241
One solution is to wrap the command with a test for eof: if perl -e 'eof() and exit(1)'; then (your;command;here); else true; fi Like this (your command = md5sum -c): echo | parallel -r -j2 -N1 --pipe "if perl -e 'eof() and exit(1)'; then ( md5sum -c ); else true; fi" This means that the process will still be spawned, but the eof-test will stop your command from being run. Also I need help with converting the if-template above to csh. Before I implement this as default for --pipe, can you see any problems with that approach? /Ole -- Did you get your GNU Parallel merchandise? https://www.gnu.org/software/parallel/merchandise.html
