What is the documented behavior of functions invocation listed in disable_functions

Question

I were not able to find a proper source stating what the intended behaviour is when invoking a function listed in disable_functions.

My observation is that a log entry is created saying something like

[04-Sep-2014 16:17:55 UTC] PHP Warning: curl_exec() has been disabled for security reasons in {file} {line}

But what does the function return in such a case? And I mean what is it documented to return?

possible duplicate of [PHP exec - check if enabled or disabled](http://stackoverflow.com/questions/2749591/php-exec-check-if-enabled-or-disabled) — Machavity, Sep 08 '14 at 15:43
Be sure to take note of the comment on the accepted answer. That should answer your question — Machavity, Sep 08 '14 at 15:44
@DCoder: perfect, thanks. That would be my accepted answer. How would I handle that? Can you transform your comment into an answer? — Adrian Föder, Sep 09 '14 at 15:23

score 1 · Accepted Answer · answered Sep 09 '14 at 17:59

This functionality is not formally documented, but if you look at the source, PHP has a placeholder function that gets called instead of a disabled function. This placeholder function only generates the warning and does not explicitly return any value. This "lack of a return value" is translated to a NULL before your PHP code sees it.

score 0 · Answer 2 · answered Sep 08 '14 at 15:48

I haven't seen it documented, but it returns NULL. With disable_functions = file_get_contents:

var_dump(file_get_contents(__FILE__));

Warning: file_get_contents() has been disabled for security reasons in test.php on line 2

NULL

Same results with curl_exec.

What is the documented behavior of functions invocation listed in disable_functions

2 Answers2