[Solved] Remotely closing X apps over ssh

Question

I'm trying to figure out a way to remotely close an application (like firefox) cleanly over ssh.  I know I could run "kill [pid]" or "killall firefox-bin" to close it, but the default termination signal causes firefox to close immediately and give a message at its next start complaining about the program not being shut down properly.  I tried several other signals, all of which had the same problem. 
Is there a signal that I can issue from kill that will be equivalent to closing the application by clicking the X, pressing Alt-F4, going to File > Quit, etc?  If not, is there some other command I can issue to accomplish the same goal?
Last edited by liquidsunshine (2009-03-30 21:56:43)

Answer 1

@Bralkein:
i like the one liner, i've incorporated it into my script.  i split it up only because i wanted more meaningful errors.
@liquidsunshine:
thanks for asking this question, this turned out a nifty script.  i use pkill all the time, now i have wkill to gracefully close programs from CLI and it works from SSH just as well as locally.
here's the finished product:
#!/bin/bash
# wKill
# pbrisbin 2009
# gracefully close a program's window from
# a remote ssh session, or not
# requires wmctrl
# example usage: wkill firefox
# always exit cleanly
errorout() {
if [ $R -eq 1 ]; then
export DISPLAY=""
fi
echo "$1"
exit $2
# set DISPLAY to your remote X session if we're ssh'd
# though: maybe a "local DISPLAY=" would work?
# it'd be cleaner if it did
if [ -z "$DISPLAY" ]; then
export DISPLAY=":0.0"
R=1
else
R=0
fi
# get the PID by process name
PID=$(pgrep "$1") || errorout "no process by the name: $1" 1
# get the hex by pid
APP=$(wmctrl -pl | grep "$PID" | awk '{print $1}')
# some things don't get reported correctly
if [ -z "$APP" ]; then
APP=$(wmctrl -l | grep "$1" | awk '{print $1}')
if [ -z "$APP" ]; then
errorout "wmctrl can't find pid: $PID or app: $1" 1
fi
fi
# close the apps window
wmctrl -i -c $APP || errorout "wmctrl could not close app: $APP" 1
# put the DISPLAY back to prevent any problems
# do this only if we set it above
if [ $R -eq 1 ]; then
export DISPLAY=""
fi
exit 0
as Bralkein said, some windows might not get reported correctly.  i added a nested if in there for two reasons:
a) anything running in a terminal (irssi, mutt, htop) will only be captured by this if they were started with the terminal.  something like `xterm -e mutt`.  if you opened xterm, then opened mutt.  it will be listed as "bash ~" or something in wmctrl and the pid would be of mutt and not xterm... so we're kinda SOL there
b) b/c i'd rather get a nice "could not find pid: X for app: Y" instead of a grep or wmctrl error message (which is what you'd get if the $APP variable is empty)
other than the CLI app issue, it should pretty much catch every exception and run quite cleanly.  now if only i knew a real programming language...
Last edited by brisbin33 (2009-03-31 00:26:49)