So there was a correction here, zsh and fish do wait for processes in the interactive part, but apparently not bash/dash/mksh: https://lobste.rs/s/om32da/unix_

So there was a correction here, zsh and fish do wait for processes in the interactive part, but apparently not bash/dash/mksh: https://lobste.rs/s/om32da/unix_process_api_is_unreliable_unsafe#c_amz4g4 https://lobste.rs/s/om32da/unix_process_api_is_unreliable_un... As far as your question, shells don't use signalfd() because it's Linux-only! Most shells predate not just signalfd(), but Linux itself :) I wouldn't use it in a newer shell for portability. If it ever came up, I probably I would use the self-pipe trick. BTW I think there was some argument awhile ago that signalfd() is actually quite bad in the presence of threads, but a shell doesn't have threads so that doesn't matter.