Brandon Allbery wrote:
If you're using a pipe
Yup.
and writing to it in the logHook,
Yup.
then the child xmobar will close automatically when xmonad restarts.
Err, Nope. At least not here it doesn't: me@mybox:~$ head -n 154 .xmonad/xmonad.hs | tail -n 10 main = do xmobarPipe <- spawnPipe "xmobar" dzenPipe <- spawnPipe "dzen2 -p -x -0" xmonad myConfig { logHook = updatePointer (Relative 1 1) >> (dynamicLogWithPP $ myDzenPP { ppOutput = hPutStrLn dzenPipe }) >> (dynamicLogWithPP $ myXmobPP { ppOutput = hPutStrLn xmobarPipe }) } me@mybox:~$ xmonad --recompile me@mybox:~$ killall xmobar dzen2 me@mybox:~$ ps ax | grep dzen2 | grep -v sh | grep -v grep | wc -l; ps ax | grep xmobar | grep -v sh | grep -v grep | wc -l 0 0 me@mybox:~$ xmonad --restart me@mybox:~$ ps ax | grep dzen2 | grep -v sh | grep -v grep | wc -l; ps ax | grep xmobar | grep -v sh | grep -v grep | wc -l 1 1 me@mybox:~$ xmonad --restart me@mybox:~$ ps ax | grep dzen2 | grep -v sh | grep -v grep | wc -l; ps ax | grep xmobar | grep -v sh | grep -v grep | wc -l 2 2 me@mybox:~$ xmonad --restart me@mybox:~$ ps ax | grep dzen2 | grep -v sh | grep -v grep | wc -l; ps ax | grep xmobar | grep -v sh | grep -v grep | wc -l 3 3
spawnPipe is not the same thing as spawn, it creates a communication channel and that is not useful and may be counterproductive if you aren't communicating with the xmobar.
which is what "ppOutput = hPutStrLn statusbarPipe" should be doing (and I'm pretty sure it works, as the status bars *are* getting data all the time). (What would be the point of having an xmobar, if you (xmonad) aren't communicating with it? (Or, rather than "not communicating" do you mean "communicating with it via stdin rather than a pipe"?))
(In particular, if xmobar isn't reading from the pipe because you didn't include a StdinReader in its config, it will never notice when that pipe gets closed.)
Don't you mean PipeReader, if we started it with spawnPipe? And presumably StdinReader would be used with the startupHook version you suggested? In any case, I had neither StdinReader nor PipeReader in my xmobar config. StdinReader doesn't fix it, and PipeReader is for named pipes, which is not what spawnPipe creates, so I wouldn't know how to configure one for this case. Obviously I'm still missing something. Thanks for all your input, it's making all sorts of things clearer.