Is there a way to simulate a “Close” event on various windows using the terminal?

Question

I answered on Ask Ubuntu Quit all instances of gnome-terminal via a command but as you all can read gnome-terminal didn't seems to have a SIGcall I could use to simulate this "Close" event. So this lead me to ask, is there a way in GNOME/KDE/LXDE/{put your window/desktop manager/environment here} to simulate the "Click in close button" event? I have read different questions that could have any relation to this, but don't answer this.

What I'm looking is for a global command (if exist) to do this in different scenarios. If none exist, please explain how the "Close" button works.

Posible uses:

• I open a set of applications for a determinated task, and want to close all of them (when no longer used) in a single stroke/command without suppress any You want to save your work? alerts.
• Close all the gnome-terminal instances but warn me if there is child process still running.
• Nothing else comes into my mind right now...

Answer 1

I believe the related man page is, XKillClient. You can use xdotool to simulate the close button being clicked from a terminal like so.

Example

Assuming I have a gnome-terminal open and it's name is "saml@grinchy:/home".

1. Get the window ID

   $ xdotool search --name "saml@grinchy:/home"
   96488188
   

2. Send it a Alt+F4

   $ xdotool windowactivate --sync 96488188 key --clearmodifiers \
        --delay 100 alt+F4
   

You can put them together by embedding the first command into the second:

$ xdotool windowactivate --sync $( ...1st command...) key --clearmodifiers \
         --delay 100 alt+F4

You can save yourself by letting xdotool do both at the same time:

$ xdotool search --name "saml@grinchy:~" key alt+f4

Globally

You can adapt what I've provided to run it on windows that have the same name:

$ xdotool search --name "saml@grinchy:~"
96488779
96468996

Or on windows by other attributes. You can use xwininfo to find out more about a particular window. Run it and then just click on the window of interest:

$ xwininfo

xwininfo: Please select the window about which you
          would like information by clicking the
          mouse in that window.

xwininfo: Window id: 0x5c04d4b "saml@grinchy:~"

  Absolute upper-left X:  14
  Absolute upper-left Y:  74
  Relative upper-left X:  14
  Relative upper-left Y:  74
  Width: 941
  Height: 361
  Depth: 32
  Visual: 0x62
  Visual Class: TrueColor
  Border width: 0
  Class: InputOutput
  Colormap: 0x5c00003 (not installed)
  Bit Gravity State: NorthWestGravity
  Window Gravity State: NorthWestGravity
  Backing Store State: NotUseful
  Save Under State: no
  Map State: IsViewable
  Override Redirect State: no
  Corners:  +14+74  -485+74  -485-465  +14-465
  -geometry 132x24+14+74

Other useful tools when dealing with X11 windows are xdpyinfo & xprop. xdpyinfo can be used to find out information about the X server. So you can figure out which window has focus:

$ xdpyinfo |grep focus
focus:  window 0x5c00005, revert to Parent

xprop and xwininfo can take a -id switch so you can provide them the Window ID that you're interested in instead of having to click on it:

$ xprop -id 0x5c00001|grep -i class
WM_CLASS(STRING) = "gnome-terminal", "Gnome-terminal"

References

• xwininfo man page
• xdpyinfo man page
• xprop man page

Answer 2

I found xdotool to be flaky/buggy, sometimes it closes the foreground window instead of the one that should be closed. This seems to be due to the way that keys are sent after bringing the window to the foreground instead of directly sending window events, and it's a very annoying issue. I suggest using wmctrl, which directly closes a window without sending keystrokes.

You can close a window directly by matching on the name, e.g. both these will close the "Untitled Document 1 - gedit" window:

wmctrl -c "gedit"
wmctrl -c "Untitled"

You can use the -F option to only consider exact matches:

wmctrl -F -c "Untitled Document 1 - gedit"

Or you can give the id directly:

wmctrl -i -c "121634821"

More usage examples/documentation can be found here.

One thing I do find very useful is xdotool's ability to wait until there is a result using the --sync argument. Combining the two in one command is done like this:

xdotool search --sync --name "gedit" | xargs wmctrl -i -c

If you are on a Mac, you'll probably need the -I{} parameter:

xdotool search --sync --name "gedit" | xargs -I{} wmctrl -i -c {}

If you want to support multiple windows, you should tell xargs to call wmctrl with at at most 1 argument each time with the -n option. wmctrl does not explicitly support multiple windows as arguments:

xdotool search --sync --name "gedit" | xargs -I{} -n 1 wmctrl -i -c {}

This will wait until there is at least 1 such window, and then closes all of them.

Answer 3

pkill(1) should be what you need.