Linux Firefox Tips

Jack Wallen
Feb 14, 2009
Updated • Dec 28, 2012

If you use Linux you most likely use Firefox. And if you use Firefox on Linux you might know there are some differences than when using it on Windows. I know I have spent many an hour trying to figure out some of these issues. Hopeful, with the help of gHacks, you won't have to spend as much time and energy.

There are two main issues that come up with Firefox (one dealing with plugins and the other dealing with a "hidden" lock file). These two issues alone could be considered deal breakers with new users. As for plugins, I am going to show you how to install the Flashplayer plugin (as that is one of the most popular and widely used plugins) on Linux-based Firefox. So, without further adieu, let's see how to get past these issues. The solutions are very simple.


I have seen Firefox behave two ways: I have seen the browser automatically install the necessary plugins, and I have seen it demand manual installation of plugins. I would like to think the automated installation is where Linux Firefox is heading, but you can never count on automation 100% of the time. For those times when you will need to install Flashplayer manually here is how you do it.

The first thing you need to do is to download the appropriate version of the Flashplayer plugin. You can get the plugin from the Adobe Flashplayer Download Page. For simplicity sake download the source file which will be a tar.gz file. Once that is downloaded unpack the file with the command:

tar xvzf install_flash_player_10_linux.tar.gz

which will create the new directory install_flash_player_10_linux/. Change into that directory with the command:

cd install_flash_player_10_linux/

and you will find two files:

  • flashplayer-installer

The file flashplayer-installer is the executable installer. In order to actually execute this you will have to give the file executable permissions with the command chmod u+x flashplayer-installer. Once you  have done this close your browser and issue the command ./flashplayer-installer. To complete the installation answer a few simple questions. Once the installer finishes, fire up Firefox and enter about:plugins in the address bar to check to make sure the plugin was installed. If all went well you should see a listing for Shockwave Flash.

Lock File

That dastardly lock file can be a real pain some times. When Firefox is running it creates a special file called a lock file in the users Firefox directory. As long as this lock file is there another instance of Firefox will not open. If Firefox crashes and the lock file isn't automatically removed by Firefox, you will get an error message saying you need to close Firefox before it will run. There are two ways to do this. You can issue the command killall -9 firefox-bin and hope it takes the lock file with it, or you can remove the lock file manually.

To remove the file manually open up a terminal window and issue the command cd ~/.mozilla/firefox. Within this directory will be a directory unique to the user. To find out the name of this directory issue the command ls. The directory will be a random string of characters. Mine, for example, is u6n8y834.default. Change into this directory and issue the command ls. You should now see a file called lock. Issue the command rm lock to remove this file. Firefox should now start up.

The issue of this lock file shouldn't come up very often. But when it does, it's nice to know how to solve the problem.

Final Thoughts

Firefox is an outstanding browser. But no matter how good it is, it can still have issues. When these issues arise, it is reassuring to know you can get beyond them. Hopefully, however, your experience with Firefox in Linux will be bereft of problems.


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  1. nka said on March 16, 2009 at 10:10 am

    They rm lock tip was a wonderful find. Whenever ff crashes and since I’m using an older machine, unfortunately this happens quite often, it is annoying getting that stupid error. With the lock file removed, no more. Thanks.

  2. Gerhard said on March 2, 2009 at 3:56 pm

    Ubuntu Intrepid: I had the “Firefox is already running…” error today and the only lock file I had was .parentlock (or something), deleted with no success. I’m sharing a profile with Windows on Ubuntu. I forgot to mount my XP partition (I prefer it manually). Only realized my problem when I managed to run “firefox -profilemanager” successfully.

    So make sure Firefox have access to selected profile.

  3. shippou said on February 15, 2009 at 3:17 am

    I have no gripes with the command line, but then there is an easier way to install flash: via Synaptic.

    This is just a suggestion.

    This is what I like in Linux: there are many ways to do the same thing. :)

  4. What is Firefox? said on February 15, 2009 at 12:39 am

    Wow, scary Linux!

    Seriously, in Ubuntu to install Flash 10 you just go to the Adobe site (Firefox takes you there if you don’t already have Flash installed but visit a page with Flash) and click Ubuntu Version. Then click Install, enter your system password, and you are done.

    As for the lock file, I’ve never had it bother me in Ubuntu. I have had a Windows computer refuse to start Firefox because it thought that Firefox was already running, but it’s never happened to me in Ubuntu.

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