<?php
    // Tracks the number of Firefox tabs.  For curiosity purposes.

    do
    {
        // I run Firefox Portable, so you'll have to find 'recovery.js' on your system and replace accordingly.
        $data = @json_decode(@file_get_contents("/FirefoxPortable/Data/profile/sessionstore-backups/recovery.js"), true);

        if ($data === false)  sleep(1);
    } while ($data === false);

    $numwindows = count($data["windows"]);
    $numtabs = 0;
    for ($x = 0; $x < count($data["windows"]); $x++)
    {
        $numtabs += count($data["windows"][$x]["tabs"]);
    }

    // In case you want to track it across time (e.g. run daily).
    $fp = fopen("/path/to/youruser/tab_tracker.csv", "ab");
    fputcsv($fp, array(date("Y-m-d"), $numtabs, $numwindows));
    fclose($fp);
?>