Select a tab in Firefox from command line

Question

Firefox already lets you open new URLs from the command line. Is there a way to select an existing tab from the command line, by title or URL?

Answer 1

Yes, there is:

• install MozRepl addon
• start it: Tools -> MozRepl -> Start

• use telnet to connect to the running MozRepl instance:

  $ telnet 127.0.0.1 4242
  

  You can also use rlwrap to enable readline-like keybindings inside telnet session:

  $ rlwrap telnet 127.0.0.1 4242
  

• define a function for searching a tab with a given URL and switching to it. This one from https://github.com/emacsmirror/cedet/blob/master/lisp/cedet/semantic/db-mozrepl.el is pretty cool:

  function semanticselecttab(url) {
       var numTabs=gBrowser.browsers.length;
       for(i=0; i<numTabs-1; i++) {
         if(gBrowser.browsers[i].contentDocument.location.href.indexOf(url)>=0) {
           gBrowser.tabContainer.selectedIndex=i;
           break;
         }
       }   
  }
  

• run it like this:

  repl> semanticselecttab("https://stackoverflow.com/questions/31055148/select-a-tab-in-firefox-from-command-line")