mgreenblog

I frequently start interactive programs from a terminal---often using the handy xdg-open script, sometimes explicitly. I sometimes remember to redirect stdout and stderr to /dev/null, but not always. Hell, half the time I forget to run the command asynchronously with &. It's easy to put a command into the background---a quick ^Z and bg and disown and you're off to the races. But it's a little harder to silence a command after the fact!

"A happy life must be to a great extent a quiet life, for it is only in an atmosphere of quiet that true joy can live." ---Bertrand Russell

I wrote a tool I call mute that uses gdb to intervene on a running program and try to redirect various file descriptors to /dev/null (or, failing that, close them). mute is pretty flexible, with the ability to specify particular file descriptors or auto-detect any file descriptor open on a tty (-t):

Usage: mute [-tfandv] [-o TARGET] PID [FD ...]

  -t         only close FDs if they are ttys (if no FDs specified, will close all tty FDs)
  -f         close FDs unconditionally
  -a         append to TARGET rather than truncating
  -n         dry run; shows the GDB script to be used, but does not run it
  -d         debug mode (shows debugging output on stdout; repeat to increase output)
  -v         show version information and exit
  -o TARGET  redirect FDs to TARGET [default: /dev/null]
             relative paths are relative to `mute`'s current directory, not PID's

  FD can be a decimal number or one of stdout, stderr, or stdin

  Running `mute PID` is the same as `mute -t PID stdout stderr`: FDs 1 and 2 will be
  closed if they are tty FDs.

I've only tested on Linux, but most of the features should work anywhere gdb works. (mute -t relies on /proc to find open file descriptors, though.)

mute is licensed under GPLv3; you can download it from https://github.com/mgree/mute/releases.

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