As we know,in Windows system left-click in firefox address bar will select the url by highlight all characters in the urlbar.So we can quickly copy and paste this url or type in another website address without manually delete the current one.In Ubuntu,this functionality for firefox is not enabled by default.Following is how to enable this!

Open a new tab in firefox window and type about:config,then click I’ll be careful,I promise!

In Filter area,type browser.urlbar.clickSelectsAll.Double click the result line and set its value to True.

Finally,restart your firefox.Left click in the address bar and see the effect!