Unknown problem with PHP's XML parsing functions

I'm using a PHP4 implementation of SimpleXML, which uses the built-in xml_* functions from PHP 4. I have an odd problem that I'm unable to diagnose due to no error reporting on the server and not being able to turn on error_reporting.

I've modified the Parse() function to include this:

[stuff here to initialise the parser]
echo '<textarea rows="8" cols="50">', htmlspecialchars($this->xml), '</textarea>';
$parsed = xml_parse($this->parser, $this->xml) or die('error with xml_parse function');

The textarea displays the XML fine, and the XML itself is perfectly valid. But the page stops right after that and doesn't appear to call the xml_parse function, or output the 'die' message.

Should also add that this works fine on other pages, it just appears to be a problem with this particular p开发者_如何学运维age for some reason.

What could be happening here? Are there other ways to debug this?

Yes, you can debug this by adding this to your script:

error_reporting(E_ALL);

Thus will turn on error reporting.

Also, using ‘or die‘ only works if the function call before it returns a falsey value. In the event of fatal errors, it doesn't help.

Try to set the error reporting on and see what error comes though, it is likely there is some fatal error coming up:

ini_set('display_errors', true);
error_reporting(E_ALL);

Try getting the XML specific parser error message:

echo xml_error_string(xml_error_code($parser));

IIRC, these are not output by default no matter what your error reporting is set to.

Reference:

• xml_get_error_code
• xml_get_error_string

It seems that the problem was due to the XML being too big for the parser. Since we can't turn on error_reporting there was no way to get proper debugging info.

I decided to use a separate script the generate the HTML for the page, to avoid issues with the page going down occasionally.