Using Eclipse to Debug PHP

With EasyEclipse and the PHP Debugger extension, you can debug and step through a PHP call.

Installing the PHP Debugger (DBG) Extension

Download the PHP Debugger (DBG); specifically the DBG 2.15.5 dbg modules for windows.
Unzip the dbg modules to a temporary directory.
Copy the relevant php extension file, currently “x86\php_dbg.dll-5.2.x” in the archive (since XAMPP 1.6 comes with PHP 5.2.5), to the extension directory “c:\xampp\php\ext” and rename it to “php_dbg.dll”.
Open up the “c:\xampp\apache\bin\php.ini” config file.
- Add this to the end of php.ini:
  [debugger]
  extension=php_dbg.dll
  debugger.enabled=on
  debugger.profiler_enabled=on
  debugger.hosts_allow=localhost
  debugger.hosts_deny=ALL
  debugger.ports=7869, 10000/16
- Search for the first instance of “zend_extension_ts” in php.ini (it should be right underneath the “[Zend]” section) and before it, add this line:
  [Zend]
  zend_extension_ts = "c:\xampp\php\ext\php_dbg.dll"
  ...
Verify that the DBG Extension is loaded:
- Stop and start the apache http server (a reload or restart won’t work).
- Create a phpinfo.php file with this content:
  <html>
  <head>
  <title>PHP Test Script</title>
  </head>
  <body>
  <?php
  phpinfo();
  ?>
  </body>
  </html>
- Install phpinfo.php under the apache root document directory and then browse to it. You will see the info on the PHP environment. If DBG is installed correctly, you should see this line:
  Zend Engine v2.2.0, Copyright (c) 1998-2007 Zend Technologies
  with DBG v2.15.5, (C) 2000,2007, by Dmitri Dmitrienko
- Search on “dbg” and you will see the configuration section for dbg also.

Disabling PHP Debugging

Once you have installed the DBG extension, debugging will be enabled and for any PHP file that is browsed to, the PHP engine will attempt to debug and fail because we have not setup a PHP Debugger service yet.
To disable debugging permanently:
1. Open up the “c:\xampp\apache\bin\php.ini” config file.
2. Change the “debugger.enabled=on” to “debugger.enabled=off”.
3. Restart the Apache HTTP server.
To disable debugging for the current active HTTP session:
1. Browse to “http://localhost/myproject/index.php?DBGSESSID=-1”.
2. This URL will remove the cookie added by the DBG extension to enable PHP debugging.

Starting the PHP Debugger Service

In order for PHP debugging to work, we must configure and start a PHP Debugger service using EasyEclipse:

Run EasyEclipse and go to menu “Run->Debug…”. If you don’t see the Run->Debug menu, then open up the Debug perspective, switch back to PHP perspective, and try again.
Select and highlight the “PHP DBG Script” and click on the New icon on the upper-left.
Input whatever Name you want.
Under the File tab, input “index.php” (or your main entrypoint PHP file). (Alternatively, you can Browse… and select it.)
Under the Arguments tab, you should see “Use default working directory” checked and the “Working Directory” is “C:\Projects”.
Under Environment tab:
- Under the Interpreter sub-tab, click the New button and browse to “c:\xampp\php\php.exe”
- Under the “Remote Debug” sub-tab, check “Remote Debug” and uncheck “Open with DBGSession URL in internal Browser”. Make sure that the Remote Sourcepath is “C:\Projects\myproject”.
- Note: It is very important that the Remote Sourcepath (and all other paths) is set correctly; otherwise the PHP debug won’t work.
Hit the Apply button.
Start the PHP Debugger service by clicking on the Debug button below the Apply button. Take note of the port number (should be 10001) that the PHP Debugger service is listening on.

Debug Tracing PHP

Open up “index.php” and set a breakpoint inside it (I suggest setting a breakpoint in the main entry routine).
- You can set a breakpoint by clicking on the leftmost vertical blue bar in the file viewer. You should see a blue dot show up and an entry added to the Debug perspective’s Breakpoints window.
- Alternatively, you can right-click on the leftmost vertical blue bar and select “Toggle PHP Breakpoint”.
Browse to “http://localhost/myproject/index.php?DBGSESSID=1@localhost:10001” and the breakpoint should be hit. You can then step into, over, or out. Yippee!
- Note: The 10001 in “localhost:10001” should match the port that the PHP Debugger is listening on in the EasyEclipse debug window.
- Passing in the request parameter DBGSESSID will create a cookie (session based), so you no longer have to pass in the DBGSESSID http parameter in subsequent requests. Yipee again!
Disable debug tracing for the current session by browsing to “http://localhost/myproject/index.php?DBGSESSID=-1”. Adding the parameter “DBGSESSID” with value “-1” will delete the debugging cookie.
CAVEAT: Unfortunately, there is a bug with the PHP Debugger service in that after servicing the HTTP request, the PHP Debugger service will terminate.
- You can quickly start the PHP Debugger service again by hitting F11 shortcut key. You will want to do this after each HTTP request is debugged.

Note: Some info above was derived from XOOPS Docman – Installing DBG.

Using Eclipse to Debug PHP

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