Question

I am having difficulty with the PHP exec() function. It seems to not be calling certain functions. For instance, the code echo exec('ls'); produces no output whatsoever (it should, there are files in the directory). That main reason this is a problem for me is that I’m trying execute a .jar from a PHP exec() call.

As far as I know I’m calling the java program properly, but I’m not getting any of the output. The .jar can be executed from the command line on the server. (For the record, it’s an apache server).

My php for the .jar execute looks like this:

$output = array();
exec('java -jar testJava.jar', $output);
print_r($output);

All I get for output from this exec() call is Array().

I have had success with exec() executing 'whoami' and 'pwd'. I can’t figure out why some functions are working and some aren’t. I’m not the most experienced person with PHP either, so I’m not too sure how to diagnose the issue. Any and all help would be appreciated.

Answer 1

I have found the issue – SELinux was blocking PHP from accessing certain functions. Putting SELinux into permissive mode has fixed the issues (although, I’d rather not have to leave SELinux in permissive mode; I’d rather find a way of allowing certain functions if I can).