This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Avatar for Username

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

This thread was archived. Please ask a new question if you need help.

Mac OS: How do I target a specific instance of Firefox from the command line when more than one instance is running?

firefox.com14
firefox.com14
more options

I use different instance of FF with different profiles as front ends for specific php applications. Sometimes when I launch a new instance via the backend script of a GUI app I've created, even though the command line arguments for the firefox binary specify the url, the instance sometimes fails to open the url and stays at the default home page. I'd like to avoid having to set the target url in the preferences for the FF profile and instead load it from the command line, as I set the url in a config file for my GUI app and don't want to have it set in multiple places.

Obviously I can get the PID of the instance, but then how would I use that (or the firefox binary) to tell that instance to open a specific URL?

Code from the script that launches FF: (included variable are defined previously) 

   browserlaunchcmd="$browserdir/Firefox.app/Contents/MacOS/firefox -P $browserprofile -no-remote \"http://$webdomain/\""
   ...
   eval "$browserlaunchcmd"
I use different instance of FF with different profiles as front ends for specific php applications. Sometimes when I launch a new instance via the backend script of a GUI app I've created, even though the command line arguments for the firefox binary specify the url, the instance sometimes fails to open the url and stays at the default home page. I'd like to avoid having to set the target url in the preferences for the FF profile and instead load it from the command line, as I set the url in a config file for my GUI app and don't want to have it set in multiple places. Obviously I can get the PID of the instance, but then how would I use that (or the firefox binary) to tell that instance to open a specific URL? Code from the script that launches FF: (included variable are defined previously) browserlaunchcmd="$browserdir/Firefox.app/Contents/MacOS/firefox -P $browserprofile -no-remote \"http://$webdomain/\"" ... eval "$browserlaunchcmd"

All Replies (1)

firefox.com14
firefox.com14 Question owner
more options

I've figured a workaround for the url not loading on launch, but still haven't figured an answer to the targeting question.

The workaround is to echo 

   user_pref('browser.startup.homepage', '[STARTUP URL]');

to the file "user.js" in the profile directory prior to issuing the FF launch command (or else check if that file with that line already exists in that folder). Coarse, but it works, and allows the URL to be set via the variable in the App's config file without duplication.

Modified by firefox.com14