Coproc Tutorial (2011)

cryptonector 2 years ago | |

You can get the pid of the process in the process redirection case (`while read ...; do ...; done < <(some_program)`) but not in the | case (`some_program | while read ...; do ...; done`).

nerdponx 2 years ago | |

I used it once for configuring Herbstluftwm and Dzen, but it was very fussy and I ended up refactoring my script later into separate processes.

0x45696e6172 2 years ago | |

I use it to launch GUI apps from the terminal, e.g.

    coproc 'nemo .'

wiml 2 years ago | | |

Is that better than using ordinary job control (nemo . &) ?

cryptonector 2 years ago | | |

Possibly. There are race conditions with `wait` for `$somepid` because shells kinda have to reap processes as soon as possible, but that means that your `$somepid` can be stale and even refer to some other process. If you have a pipe from the process' stdout and/or stderr then when you can try to read from that pipe to know if the process exited -- you might still lose the exit status, unless you run the program like `(the_program ...; stat=$?; printf '%s\n' $stat 1>&2; exit $stat) &` and then read the exit status from the stderr pipe.

wavemode 2 years ago | | |

Most GUI apps are noisy as hell in their output.

Though I guess there's always nemo . >/dev/null 2>&1 &