System Call

rgraves

Hi,

A coworker of mine has a perl script that he uses to authenticate users on our system. He has "exit 1;" in the script to return a 1 if the authentication succeeds and "exit 0;" to return 0 otherwise.

I've tried running the script using the PHP system() function however, I am unable to retrieve the value from his exit condition. My guess as to why this was not working was because his script is not printing the value to stdout.

Does anyone know how I can retrieve this value from his script?

biggus

have you tried exec()?

http://us3.php.net/manual/en/function.exec.php

Biggus

rgraves

Yep, no luck with exec() either.

biggus

could you post your code (the call) and the OS info? I've done similar things a few time and may be able to help (aside from my hasty previous attempt)

Biggus

rgraves

Here's the code for my system call

$auth = system("/path/to/auth/script/phpauth ". escapeshellarg($POST['username']) ." ". escapeshellarg($POST['password']));

Here is a piece of his perl script (called phpauth):

@args = ($authprog, $user, $pass, $group);

$return = system @args;

if ($return == 0 ) {
exit 1;
}
else {
exit 0; #unauthorized

}

As for our server, here are the specs:

OS: Solaris 9
PHP: v.4.3.10

laserlight

What if you try:

$auth = system("/path/to/auth/script/phpauth "
	. escapeshellarg($_POST['username']) . " "
	. escapeshellarg($_POST['password']), $status);
//use $status as result from exit() in external script

rgraves

Humm,

That returned 1 when I used my correct username / password. However when I changed the password to test an incorrect combination, it still returned 1.

Unless you can spot a problem with the PHP code that would cause this, I will check with my coworker to ensure the problem is not with his authentication script.

Thanks for your help!

laserlight

I think the problem could be that exit is intended to state whether the script ran successfully or failed.
Wouldnt it be simpler if you modified the Perl script to print 1 and print 0 instead?
Then $auth would contain what you want.

EDIT:
not quite, since you're using system().

You would use:
exec(..., $auth);
//$auth[0] should be either 1 or 0

rgraves

Hi,

I was just going through the PHP documentation again before reading your reply and I also got the impression that $status would return 1 if the script ran successfully. This certainly makes sense.

Having the perl script just print the value to stdout was my first solution but I figured I'd ask to see if there was another way to fetch the result.

Thanks for your assistance everyone!

laserlight

I also got the impression that $status would return 1 if the script ran successfully

Actually, I think you cant rely on $status - for example, I tested with a C++ program, and since main() returns 0 on success, $status would be 0.