Gnome: how to close all applications

gnomeshutdown

I've configured the Debian system on my netbook to shut down whenever the battery runs too low. Problem is, shutting down kills all running applications without giving them any chance to save any document I may be working on.

I'd like to write a script to "gently" close all open applications before shutdown kicks in, but I can't find a way to broadcast a "Close" message to all running applications in Gnome. Is there a way?

Thanks.

EDIT: Hibernating does not work on my netbook, so I can't use it as an alternative solution.

Best Answer

You could ask gnome to close the current session before the shutdown. Something like:

gnome-session-quit --logout --no-prompt
shutdown -h now

The command syntax can change according to gnome version (e.g. gnome-session-quit is the new name of gnome-session-save).

The --no-prompt force running applications to quit without user confirmation.

Related Solutions

Debian – way to control the delay before shutdown on low battery

I don't use it, but a few google searches and it looks like GNOME Power Manager isn't that configurable (i.e., there are reports that it doesn't allow any customization).

That being the case I'd recomend switching to something else (e.g, acpid, hal, devicekit-power, etc.) that is scriptable.

Find (or create) the script that runs on the low battery event and use zenity to give yourself a warning, schedule a shutdown.

zenity --warning --title "Battery" --text "Low battery. (state = $state)" &
shutdown -h -t 300

The 300 gives you 5 minutes (customize this for your needs).

There will also be an "ac" event, when you plug into AC power. You'll want this event to cancel any pending shutdown.

shutdown -c

Sorry it's not a complete solution, but there are many ways to do this.

Linux – Can it harm if I shutdown without closing applications

TL;DR

It's a best-practice to close any applications that might have unsaved data before shutting down.

Longer Explanation

It is the individual application's responsibility to gracefully handle a SIGTERM, but there are certainly cases where this will not suffice. Two examples that could cause data loss are:

An application does not properly handle (or even ignores) SIGTERM.
The application takes longer to save its data than the system allows before sending SIGKILL (e.g. around 5 seconds on Ubuntu according to the upstart cookbok).

A Few Practical Examples

I would personally recommend closing open documents in your text editor or word processor, but I wouldn't worry about Tomboy notes or open Firefox tabs. You should probably take care with any bulk file transfers in Nautilus, but I wouldn't worry about a resumable download with wget or transmission.

Like all things Unix-like, YMMV.