error-reporting-display.txt

How to get PHP errors to log/display

TL;DR:

Put/modify this in the php.ini file:
error_reporting = -1
display_errors = On

Long version:

1. In case you have an access to the php.ini file:

	1a. Open your php.ini file

		If you don't know where is this php.ini file located, create a new file like blah.php and put this there: <?php phpinfo();
		Open it in your browser
		Under "Loaded Configuration File" you'll find the path to the ini file

		Now put or modify this in the php.ini file:
		
		error_reporting = -1
		display_errors = On
		display_startup_errors = On
		log_errors = On
		;the below path is just an example
		error_log = /tmp/php_errors.log
		
		

	2b.	Restart your webserver/fastcgi-listeners. 
		Restarting Apache:
			Debian and Debian-based (e.g. Ubuntu): sudo service apache2 restart
			OS X: sudo apachectl -k restart 


	Side note: The above solution is better than using ini_set() and error_reporting() in the script (described below),becase the latter will fail 
	if there are parse errors. 


2. In case you don't have access to php.ini file for any reason:

	2a. Put this at the top of your script

		ini_set('display_errors', 1);
		ini_set('display_startup_errors', 1);
		error_reporting(-1);

	2b. That's all.

	Side note: when using this method you will not see syntax errors.
 
 3. More side notes
 
 	3a. You can easily "watch" the log file, like this:
 		tail -f /tmp/php_errors.log

	3b. You should consider having two setups, one for dev environment, and one for production. In the latter you don't want to *display* errors,
	so you can create two versions of php.ini file and in the production version put display_errors = Off and display_startup_errors = Off or in the php code:
	
		define('ENVIRONMENT','DEV');//or 'PROD';
		
		//these are for both environments, even on production we want to have the errors logged to a file, we just don't want them to be displayed on the screen 
		error_reporting(-1);
		ini_set ('log_errors',1);
		ini_set ('error_log','/tmp/php_errors.log');
		
		if (ENVIRONMENT === 'DEV'){
			ini_set('display_errors',1);
			ini_set('display_startup_errors',1);
		}else{//production env
			ini_set('display_errors',0);
			ini_set('display_startup_errors',0);
		}

	3c. There is one thing with PDO. By default, PDO::ATTR_ERRMODE is set to ERRMODE_SILENT. This means, if there is an error in SQL/Whatever, PDO will throw no exceptions and it will issue no warnings. You want to change it to:
	
    	$dbh = new PDO("mysql:host=localhost;dbname=DATABASE_NAME",'USER','PASSWORD',[
	  PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION;//this is if you want exceptions to be thrown, you can also use PDO::ERRMODE_WARNING to generate warnings.
	]);	
	
	side note: PDO::__construct will always throw an exception if the connection fails.