[php] Check if xdebug is working

Without installing a texteditor or an IDE, is it possible to test if xdebug is working, i.e. if it can debug php code?

The only part xdebug comes up in phpinfo() is the following:

Additional .ini files parsed /etc/php5/apache2/conf.d/mysql.ini, /etc/php5/apache2/conf.d/mysqli.ini, /etc/php5/apache2/conf.d/pdo.ini, /etc/php5/apache2/conf.d/pdo_mysql.ini, /etc/php5/apache2/conf.d/xdebug.ini

It is not mentioned in the phpinfo() anywhere else.

Just to extend KsaRs answer and provide a possibility to check xdebug from command line:

php -r "echo (extension_loaded('xdebug') ? '' : 'non '), 'exists';"

you can run this small php code

<?php
phpinfo();
?>

Copy the whole output page, paste it in this link. Then analyze. It will show if Xdebug is installed or not. And it will give instructions to complete the installation.

in your question you mentioned that your phpinfo was stating that apache was loading xdebug's configuration in /etc/php5/apache2/conf.d/xdebug.ini In many of the instructions online you may note that they ask you to put xdebug config in php.ini (and that is what I did) HOWEVER, if the configuration is set to /etc/php5/apache2/conf.d/xdebug.ini, then you should remove the [XDebug] configuration settings from /etc/php5/apache2/php.ini and put it in /etc/php5/apache2/conf.d/xdebug.ini INSTEAD. Once I removed from /etc/php5/apache2/php.ini and put in /etc/php5/apache2/conf.d/xdebug.ini instead, and restarted apache, it worked!!

Therefore, in your /etc/php5/apache2/conf.d/xdebug.ini, put the following:

[XDebug]
zend_extension="/usr/lib/php5/20121212+lfs/xdebug.so"
xdebug.remote_enable=1
xdebug.remote_port="9000"
xdebug.profiler_enable=1
xdebug.profiler_output_dir="/home/paul/tmp"

xdebug.remote_host="localhost"
xdebug.remote_handler="dbgp";
xdebug.idekey="phpstorm_xdebug"

then remove this from the /etc/php5/apache2/php.ini if you put it there as well.

Then do:

sudo service apache2 restart

Then it should work!!!

After a bitter almost 24 hours long run trying to make xdebug to work with Netbeans 8.0.2, I have found a solution that, I hope, will work for all Ubuntu and Ubuntu related stacks.

Problem number 1: PHP and xdebug versions must be compatible

Sometimes, if you're running a Linux setup and apt-get to install xdebug, it won't get you the proper xdebug version. In my case, I had the latest php version but an old xdebug version. That must be due to my current Xubuntu version. Software versions are dependent on repositories, which are dependent on the OS version you are running.

Solution: PHP has a neat extension manager called PECL. Follow the instructions given here to have it up and running. First, as pointed out by a member at the comments, you should install PHP's developer package in order to get PECL to work:

sudo apt-get install php5-dev

Then, using PECL, you'll be able to install the latest stable version of xdebug:

sudo pecl install php5-xdebug

Once you do it, the proper version of xdebug will be installed but not ready to use. After that, you'll need to enable it. I've seen many suggestions on how to do it, but the fact of the matter is that PHP needs some modules to be enabled both to the client and the server, in this case Apache. It seems that the best practice here is to use the built in method of enabling modules, called php5enmod. Usage is described here.

Problem number 2: Enable the module correctly

First, you'll need to go inside the /etc/php5 folder. In there, you'll find 3 folders, apache2, cli, and mods_available. The mods_available folder contains text files with instructions to activate a given module. The name convention is [module].ini. Take a look inside a few of them, see how they are set up.

Now you'll have to create your ini file inside mods_available folder. Create a file named xdebug.ini, and inside the file, paste this:

[xdebug]
zend_extension = /usr/lib/php5/20121212/xdebug.so
xdebug.remote_enable=on
xdebug.remote_handler=dbgp
xdebug.remote_mode=req
xdebug.remote_host=localhost
xdebug.remote_port=9000

Make sure that the directive [xdebug] is present, exactly like the example above. It is imperative for the module to work. In fact, just copy and paste the whole code, you'll be a happier person that way. :D

Note: the zend_extension path is very important. On this example it is pointing o the current version of the PHP engine, but you should first go to /usr/lib/php5 and make sure the folder that is named with numbers is the correct one. Adjust the name to whatever you see there, and while you're at it, check inside the folder to make sure the xdebug.so is really there. It should be, if you did everything right.

Now, with your xdebug.ini created, it's time to enable the module. To do that, open a console and type:

php5enmod xdebug

If everything went right, PHP created two links to this file, one inside /etc/php5/apache2/conf.d and other inside /etc/php5/cli/conf.d

Restart your Apache server and type this on the console:

php -v

You should get something like this:

PHP 5.5.9-1ubuntu4.6 (cli) (built: Feb 13 2015 19:17:11) 
Copyright (c) 1997-2014 The PHP Group
Zend Engine v2.5.0, Copyright (c) 1998-2014 Zend Technologies
with Zend OPcache v7.0.3, Copyright (c) 1999-2014, by Zend Technologies
with Xdebug v2.3.1, Copyright (c) 2002-2015, by Derick Rethans

Which means the PHP client did read your xdebug.ini file and loaded the xdebug.so module. So far so good.

Now create a phpinfo script somewhere on your web server, and run it. This is what you should see, if everything went wright:

If you see this, Apache also loaded the module, and you are probably ready to go. Now let's see if Netbeans will debug correctly. Create a very simple script, add some variables, give them values, and set a break point on them. Now hit CTRL+F5, click on "step in" on your debugger panel, and see if you get something like this:

Remember to check Netbeans configuration for debugging, under tools/options/php. It should look something like this:

I hope this sheds some light on this rather obscure, confusing problem.

Best wishes!

If you are using Eclipse then please note that while running on XDebug mode the magic constant __FILE__ will always be evaluated to:

xdebug://debug-eval

So the following check will return true if your session is under XDebug:

$is_xdebug = false !== strpos(__FILE__,'xdebug'); // true while on XDebug

Starting with xdebug 3 you can use the following command line :

php -r "xdebug_info();"

And it will display useful information about your xdebug installation.

Try as following, should return "exists" or "non exists":

<?php
echo (extension_loaded('xdebug') ? '' : 'non '), 'exists';

Run

php -m -c

in your terminal, and then look for [Zend Modules]. It should be somewhere there if it is loaded!

NB

If you're using Ubuntu, it may not show up here because you need to add the xdebug settings from /etc/php5/apache2/php.ini into /etc/php5/cli/php.ini. Mine are

[xdebug]
zend_extension = /usr/lib/php5/20121212/xdebug.so
xdebug.remote_enable=on
xdebug.remote_handler=dbgp
xdebug.remote_mode=req
xdebug.remote_host=localhost
xdebug.remote_port=9000