How do you debug PHP scripts? [closed]

Answer 1

PhpEd is really good. You can step into/over/out of functions. You can run ad-hoc code, inspect variables, change variables. It is amazing.

Answer 2

PhpEdit has a built in debugger, but I usually end up using echo(); and print_r(); the old fashioned way!!

Answer 3

+1 for print_r(). Use it to dump out the contents of an object or variable. To make it more readable, do it with a pre tag so you don't need to view source.

echo '<pre>';
print_r($arrayOrObject);

Also var_dump($thing) - this is very useful to see the type of subthings

Answer 4

XDebug is essential for development. I install it before any other extension. It gives you stack traces on any error and you can enable profiling easily.

For a quick look at a data structure use var_dump(). Don't use print_r() because you'll have to surround it with <pre> and it only prints one var at a time.

<?php var_dump(__FILE__, __LINE__, $_REQUEST); ?>

For a real debugging environment the best I've found is Komodo IDE but it costs $$.

Answer 5

I often use CakePHP when Rails isn't possible. To debug errors I usually find the error.log in the tmp folder and tail it in the terminal with the command...

tail -f app/tmp/logs/error.log

It give's you running dialog from cake of what is going on, which is pretty handy, if you want to output something to it mid code you can use.

$this->log('xxxx');

This can usually give you a good idea of what is going on/wrong.

Answer 6

Well, to some degree it depends on where things are going south. That's the first thing I try to isolate, and then I'll use echo/print_r() as necessary.

NB: You guys know that you can pass true as a second argument to print_r() and it'll return the output instead of printing it? E.g.:

echo "<pre>".print_r($var, true)."</pre>";