Refreshing Browsers over SSH

Today I was faced with the challenge of having to refresh a Chrome browser window on a networked Ubuntu machine via SSH. (Admittedly, I could have walked over to the computer in question and hit F5, but where’s the fun in that?) This seemed like it would be simple, but I immediately ran into problems.

Opening Chrome

My first thought was to see if Google Chrome’s command-line interface has any support for interacting with existing windows, but unfortunately it doesn’t. Oh well - if the browser is set to remember the last opened tabs, then it should just be a matter of closing and reopening the window: once I SSH in,

sudo killall chrome
google-chrome & > /dev/null

should be all it takes, right?

Well, not quite:

(chromium-browser:3217): Gtk-WARNING **: cannot open display:

Hmm, Chrome refuses to start because it can’t find a display. Since we’re logged in remotely, we’ll need to manually set the display to be the one that is currently being used:

export DISPLAY=:0.0

After this, running google-chrome works. So far, so good.

Now comes the next problem: the original window was full screen. Could I make the new instance be full screen as well?

Making it full screen

Suprisingly, there is no command-line switch for full-screen mode! The closest I could find was –app, which didn’t seem to do anything. Well, if we can’t start the browser in full screen, can we at least make the window full screen after it starts?

Here the xdotool keyboard/mouse simulator package can come in handy - we can use it to mimic an F11 keypress as follows:

# You might need to sudo apt-get install xdotool
xdotool search chrome windowactivate --sync key F11

Now all that’s left is the matter of timing: we should only run xdotool once Chrome’s window has opened, so let’s give it a few seconds:

sleep 2

Putting it all together

The full sequence of commands to run is:

export DISPLAY=:0.0
sudo killall chrome
google-chrome & > /dev/null
sleep 2
xdotool search chrome windowactivate --sync key F11

Since I don’t want to have to enter this every time I need to refresh the browser, I saved this into a shell file on the remote machine at ~/local/bin/google-chrome-fullscreen and assigned appropriate permissions. Now, to refresh chrome on that machine, all I need to run is:

ssh <host> 'google-chrome-fullscreen > /dev/null'

(The > /dev/null is necessary, apparently because otherwise the SSH session hangs while waiting for output.)

What about other browsers?

Similar method should work for other browsers. A generic browser-refresh script that works for me is:

#!/bin/sh
# refresh_fullscreen

export DISPLAY=:0.0
sudo killall $1
$1 & > /dev/null
sleep 2
xdotool search $1 windowactivate --sync key F11

where the usage is

refresh_fullscreen <browser name or path>

I’ve tried this with Firefox and Chromium and it seems to work fine, but your mileage may vary.

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