This Tampermonkey script extracts the a Splunk search's run duration and displays it in the title of the tab.

splunk_search_duration.js

```js
// ==UserScript==
// @name         Extract Splunk Search Run Duration
// @namespace    http://*
// @version      1.0
// @description  This script extracts the a Splunk search's run duration and displays it in the title of the tab.
// @match        http://splunk.example.com:8000/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    console.log('Script is running...');

    // Function to format the duration
    function formatDuration(duration) {
        if (duration < 60) {
            return duration.toFixed(0) + ' seconds';
        } else {
            var minutes = Math.floor(duration / 60);
            var seconds = duration % 60;
            return minutes + ' min' + (minutes > 1 ? 's ' : ' ') + seconds.toFixed(0) + ' sec';
        }
    }

    // Function to run the script logic
    function runScript() {
        // Select the element with class "extract-fields-button"
        var element = document.querySelector('.extract-fields-button');

        // Check if the element is found
        if (element) {
            console.log('Element with class "extract-fields-button" found.');

            // Get the value of the href attribute
            var hrefValue = element.getAttribute('href');

            // Define your regular expression
            var regex = /sid\=(?<sid>.*)/;

            // Match the regex against the href value
            var match = hrefValue.match(regex);

            // Check if there's a match
            if (match) {
                console.log('Regex pattern matched.');

                // Extract the value of the named capture group 'sid'
                var sidValue = match.groups.sid;
                console.log('sid value:', sidValue);

                // Build the URL using the extracted sid value and the current base URL
                var baseUrl = `${window.location.origin}/en-US/splunkd/__raw/services/search/jobs/`;
                var finalUrl = `${baseUrl}${sidValue}?output_mode=json&message_level=debug`;
                console.log('Final URL:', finalUrl);

                // Fetch data from the constructed URL
                fetch(finalUrl)
                    .then(response => response.json())
                    .then(data => {
                        // Log the full JSON payload
                        console.log('Full JSON:', data);

                        // Extract the desired field from the JSON payload
                        var runDuration = data.entry[0].content.runDuration; // Duration in seconds
                        console.log('runDuration:', runDuration);

                        // Format the run duration
                        var formattedDuration = formatDuration(runDuration);

                        // Update page title with formatted duration
                        document.title = document.title.split(' | ')[0] + ' | ' + formattedDuration;
                    })
                    .catch(error => {
                        console.error('Error fetching data:', error);
                    });
            } else {
                console.log('Regex pattern not found in href value.');
            }
        } else {
            console.log('Element with class "extract-fields-button" not found.');
        }
    }

    // Run the script initially
    runScript();

    // Set interval to rerun the script every 5 seconds
    setInterval(runScript, 5000); // 5000 milliseconds = 5 seconds
})();
```