Read HepMC events from pipe

[michael]

Hello,

I have some LHE events I’m passing through pythia8 and then delphes (v 3.3.2). Rather than store the huge HepMC file to disk and then pass it to DelphesHepMC, is there a way of piping the HepMC output directly to delphes on-the-fly? I’ve tried outputting the HepMC to a named pipe (e.g. hepmc.fifo) and using that pipe as a third argument for DelphesHepMC, but this does not work. Writing the HepMC output to stdout and reading that as stdin in DelphesHepMC does not work either, because then DelphesHepMC parses all the pythia info messages and banner as HepMC input too, and complains about invalid syntax. Is there a way of doing this?

Best,
Michael

[Pavel Demin]

I think that the following should work with a named pipe:

cat hepmc.fifo | ./DelphesHepMC cards/delphes_card_CMS.tcl delphes_output.root