Find PID of browser process launched by Selenium WebDriver

Question

In C# I start up a browser for testing, I want to get the PID so that on my winforms application I can kill any remaining ghost processes started

driver = new FirefoxDriver();

How can I get the PID?

Answer 1

Looks more like a C# question, instead of Selenium specific.

This is a very old non-deterministic answer, please reconsider if you want to try this out.

My logic would be you get all process PIDs with the name firefox using Process.GetProcessesByName Method, then start your FirefoxDriver, then get the processes' PIDs again, compare them to get the PIDs just started. In this case, it doesn't matter how many processes have been started by a specific driver (For example, Chrome starts multiple, Firefox only one).

using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using OpenQA.Selenium.Firefox;

namespace TestProcess {
    [TestClass]
    public class UnitTest1 {
        [TestMethod]
        public void TestMethod1() {
            IEnumerable<int> pidsBefore = Process.GetProcessesByName("firefox").Select(p => p.Id);

            FirefoxDriver driver = new FirefoxDriver();
            IEnumerable<int> pidsAfter = Process.GetProcessesByName("firefox").Select(p => p.Id);

            IEnumerable<int> newFirefoxPids = pidsAfter.Except(pidsBefore);

            // do some stuff with PID if you want to kill them, do the following
            foreach (int pid in newFirefoxPids) {
                Process.GetProcessById(pid).Kill();
            }
        }
    }
}

Answer 2

var g = Guid.NewGuid();
driver.Navigate().GoToUrl("about:blank");
driver.ExecuteScript($"document.title = '{g}'");
var pid = Process.GetProcessesByName("firefox").First(p => 
p.MainWindowTitle.Contains(g.ToString()));

Answer 3

I didn't try with Firefox, but that is the way that works with Chrome:

        // creating a driver service
        var driverService = ChromeDriverService.CreateDefaultService();
        _driver = new ChromeDriver(driverService);

        //create list of process id
        var driverProcessIds = new List<int> { driverService.ProcessId };

        //Get all the childs generated by the driver like conhost, chrome.exe...
        var mos = new System.Management.ManagementObjectSearcher($"Select * From Win32_Process Where ParentProcessID={driverService.ProcessId}");
        foreach (var mo in mos.Get())
        {
            var pid = Convert.ToInt32(mo["ProcessID"]);
            driverProcessIds.Add(pid);
        }

        //Kill all
        foreach (var id in driverProcessIds)
        {
            System.Diagnostics.Process.GetProcessById(id).Kill();
        }

Answer 4

        int _processId = -1;

        var cService = ChromeDriverService.CreateDefaultService();
        cService.HideCommandPromptWindow = true;

        // Optional
        var options = new ChromeOptions();
        options.AddArgument("--headless");

        IWebDriver webdriver = new ChromeDriver(cService, options);
        _processId = cService.ProcessId;

        Console.Write("Process Id : " + _processId);

        webdriver.Navigate().GoToUrl("https://www.google.lk");

        webdriver.Close();
        webdriver.Quit();
        webdriver.Dispose();