Finding errors due to register globals?

[Kevin Thorpe]

I don't suppose anyone knows of a script/program to try and identify
where variables are used assuming register_global s is on? I'm trying to
fix an application and would rather not turn it on as there are several
applications on the server.

I'm thinking of something which can identify use of variables (right
hand side of assignments) before definition (left hand side of assignments).

Any pointers?

[Pedro Graca]

Re: Finding errors due to register globals?

Kevin Thorpe wrote:[color=blue]
> I don't suppose anyone knows of a script/program to try and identify
> where variables are used assuming register_global s is on? I'm trying to
> fix an application and would rather not turn it on as there are several
> applications on the server.
>
> I'm thinking of something which can identify use of variables (right
> hand side of assignments) before definition (left hand side of assignments).
>
> Any pointers?[/color]

http://www.php.net/error_reporting

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[Kevin Thorpe]

Re: Finding errors due to register globals?

Pedro Graca wrote:
[color=blue]
> Kevin Thorpe wrote:
>[color=green]
>>I don't suppose anyone knows of a script/program to try and identify
>>where variables are used assuming register_global s is on? I'm trying to
>>fix an application and would rather not turn it on as there are several
>>application s on the server.
>>
>>I'm thinking of something which can identify use of variables (right
>>hand side of assignments) before definition (left hand side of assignments).
>>
>>Any pointers?[/color]
>
>
> http://www.php.net/error_reporting
>[/color]
Unfortunately that's only at runtime. I don't rely on default values for
variables and have turned on all the error checking but I still need to
read every line of code or perform a comprehensive test to execute every
line.

I was hoping someone had a script to assist. If php was compiled then
these errors would be caught at compile time.

[Pedro Graca]

Re: Finding errors due to register globals?

Kevin Thorpe wrote:[color=blue]
> Pedro Graca wrote:[color=green]
>> Kevin Thorpe wrote:[color=darkred]
>>>Any pointers?[/color]
>>
>> http://www.php.net/error_reporting[/color]
>
> Unfortunately that's only at runtime. ...[/color]

There's no saying where a uninitialized variable can be used ...
It can be on the right side of an assignment; as a parameter to a
function call; on the left side of a test; ...

Good luck in finding a script that finds them all :)



You might want to try installing the scripts in a test directory and set
auto_prepend_fi le in that directory to a script that sets error_handler
to a function that logs all notices to a file (or database, or ...).

Make a few test runs, examine the log, and (manually) correct the
errors.


Skeleton auto_prepend_fi le

<?php
function Notice_Handler( $n, $d, $f, $l) {
if ($n == 8) {
// log $d, $f, and $l somewhere
}
}

set_error_handl er('Notice_Hand ler');
?>

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[Kevin Thorpe]

Re: Finding errors due to register globals?

> There's no saying where a uninitialized variable can be used ...[color=blue]
> It can be on the right side of an assignment; as a parameter to a
> function call; on the left side of a test; ...
>
> Good luck in finding a script that finds them all :)
>[/color]
I know. Looking into it requires writing a full parser. I can do that
but is it really worth my time? php syntax is pretty complex with
embedded variables and such so it's a lot of work. Maybe I should do it
and make it GPL, but I'm not sure I have the time.
[color=blue]
> You might want to try installing the scripts in a test directory and set
> auto_prepend_fi le in that directory to a script that sets error_handler
> to a function that logs all notices to a file (or database, or ...).[/color]

That still requires a test script (or me) to exercise all the code. Lots
of work for a one-off intranet app.

People keep hitting this problem, it's a FAQ. I was just wishfully
thinking that it had been addressed. Are there any zend people listening?