exec() silliness

Anon

Howdy,

Trying to call an executable from my PHP script:

$cmd = "/path/binary";

File permissions on /path/binary are rwxr-xr-x, also tried rwsr-xr-x

$params = " parameter list";

$run = exec($cmd.$params, $return_array);

When the script runs, /path/binary does not execute, and both $run and $return_array are empty.

HOWEVER, when I just run exec($cmd, $return_array) - note no parameters passed to /path/binary, it returns the usage help for /path/binary - just as one would expect when running from a shell w/out parameters.

The parameters are valid, I can run /path/binary <params> from a shell (as user nobody).

One thing that comes to mind - /path/binary is dynamically linked (uses shared objects). I have tried setting permissions on the lib.so files called by the binary, but to no avail.

Anyone out there had this before?

Regards,
Iven

Anon

Some troubleshooting steps:

Echo the command line so that you can verify it is constructed the way you want.
Make sure you are not running the args together with the command. You are not in this example, but it is a common error. An easy way of avoiding it to use "$command $args" rather than the concatenation operator.
Try constructing an example of how you want to look and exec() it to see if it works.

Anon

Thanks for the reply,

I have done :

$full_cmd = $cmd.$params;
echo $full_cmd;

Then copied and pasted the result of this from browser to shell, and run it successfully as user nobody.

I have also hardset the full command, i.e. $cmd = \"/path/binary -a 1 -b 2 -c 3\"; exec($cmd);

I get the same thing, nothing.

Still stuck, thanks for the tips tho...

Anon

FYI, fixed my prob ... had nothing to do with PHP 😛

after wrappering the external binary in strace, it showed that the prog (C++ binary) wasn't able to find its config file (even though it was located in the same dir).

so I hacked a config file specification option into the C prog, run that as parameter in exec(), and all is good.

it sure would be nice though if exec() and similar functions would let you define a working directory for external progs ...

Anon

Try a chdir() before exec().