PHP error reporting

Error levels		 name		 value		 description		 example 1		 example 2		 E_ERROR		 1		 Fatal run-time errors		 notdefined();		 E_WARNING		 2		 Run-time warnings		 1 / 0;		 E_PARSE		 4		 Compile-time parse errors		 +-;		E_eval(‘+-;’);		 E_NOTICE		 8		 Run-time notices		 print $i_am_not_defined;		 E_CORE_*		 varies		 generated by PHP core		 E_USER_*		 varies		 generated by trigger_error		 E_ALL		 2047		 EverythingCustom Error Handler
It can only catch E_WARNING, E_PARSE, E_USER_ERROR, E_USER_WARNING and E_USER_NOTICE. If something else happens, PHP’s default error handler takes place.
functional my_error_handler($errno, $error, $file, $line) { ... handle the error ...}
set_error_handler(‘my_error_handler’);
Apache
In Apache, you can customize how it responses to a particular HTTP status code. It can show a message or load a specific page. e.g. (from Apache’s doc)
ErrorDocument 500 /cgi-bin/crash-recoverErrorDocument 500 "Sorry, our script crashed. Oh dearErrorDocument 500 http://xxx/ErrorDocument 404 /Lame_excuses/not_found.htmlErrorDocument 401 /Subscription/how_to_subscribe.html
However, when executed as an Apache module PHP returns a HTTP status code of 200 (OK) even if there is an compile or run-time error. (Not sure if it’s a bug or a feature, since this behavior is not mentioned anywhere else.) Therefore, one cannot use Apache’s custom error capability for PHP errors.
Instead, either use a custom error handler (see above) or have PHP wrap the message inside some specific HTML code (see below).
Pretty-printing Error Messages
Config keys error_prepend_string and error_append_string are used to determine the HTML code that prepends or appends an error message.
e.g. To display each error message inside a box, put these in php.ini:
; String to output before an error message.error_prepend_string = "<fieldset>An error has occured. Please notify the <a href=\"mailto:admin@yourname.com\">administrator</a> with the following error message: <br>"; String to output after an error message.error_append_string = "</fieldset>"
To make the change effective to a directory instead of system-wide, put these in .htaccess:
php_value error_prepend_string "(... starting tags ...)"php_value error_append_string "(... ending tags ...)"
Note: Because any compile-time error stops the compilation, there will be at most one box.