Turning PHP warnings into User defined Exception

Question

Language Used: PHP
Version: 5.6

I am trying to upload a file to the server with the following function:

move_uploaded_file($source,$destination);

Whenever file fails to upload due to any reason such as

Permission denied,

No Destination folder found,

etc

It simply raises a warning and continues with other parts of the code. But I want to catch that warning and change the flow of the program if any of the warnings are raised with their name so that I can throw appropriate Exception.

I am currently using try{}catch(){} block to upload a file but an exception is not raised for the warning.

Edited Found this...

move_uploaded_file($source,$destination);

returns true or false based on status of file upload. But it does not specify reason. How to know that?

It's a warning, so it won't throw it's own exception. [move_uploaded_file](https://www.php.net/manual/en/function.move-uploaded-file.php) returns false if it fails, so you can always throw your own exception there. — aynber, Nov 13 '19 at 18:39
@aynber Thanks for your input. But, what if want to know the reason behind failure of file upload? — Jain Rishav Amit, Nov 13 '19 at 18:42
You might want to look here (https://stackoverflow.com/questions/1241728/can-i-try-catch-a-warning). Using the error handler should allow you to get more information. — aynber, Nov 13 '19 at 18:44
In the error handler you can then look for `Permission denied` etc... — AbraCadaver, Nov 13 '19 at 18:50
If you are still using PHP 5 I strongly recommend to upgrade as soon as possible. This version is no longer supported. [Let Rasmus Lerdorf explain it to you](https://youtu.be/wCZ5TJCBWMg?t=2434) — Dharman, Nov 13 '19 at 23:48

score 0 · Answer 1 · edited Nov 13 '19 at 23:49

I guess set_error_handler() would be the right choice. Make sure your read the documentation carefully.

https://www.php.net/manual/en/function.set-error-handler.php.

First, you'd need an function (or public class-method) to handle the error. Example:

function error_handler($code, $text, $file, $line) {
    echo sprintf('code: %s, text: %s, file: %s, line: %s', $code, $text, $file, $line );

    return false; // continue with PHPs error handling
}

Second, call set_error_handler somewhere in your init/bootstrap code. Specify your error_handler method and set appropriate flags for which situations you want to be informed.

$flags = E_ALL & ~(E_STRICT | E_NOTICE);
set_error_handler('error_handler', $flags);
error_reporting($flags);

A word of warning: If you intend to catch errors like out-of-memory, your code should be prepared to use as less memory as possible. Also resources may not be available anymore (like database connections or file handles).

Turning PHP warnings into User defined Exception

1 Answers1