System/Exec/`` Problem

[moejoe22]

I am trying to get php to send a signal to a concurrently running c/c++ program. I have tried several ways of attempting this but every time the php route fails.

 

I can from terminal send the appropriate signal and the c/c++ program(s) will acknowledge receiving the signal (I have custom handlers written for them) but when I try through php it does nothing.

 

Here's an example of some of the things I've tried:

 

    $y = `./sendsig`;

    system("./sendsig", $x);

    system("./sikil", $z); 

    exec("./sendsig");

 

sendsig is a shell script I wrote that when run from terminal sends the right signal to the c/c++ prog and the program acknowledges the signal.

 

    $y = `./siint`;

    system("./siint", $x);

    system("./siint", $z); 

    exec("./"siint);

 

siint is another c program that I wrote that sends the right signal to the c/c++ program and it acknowledges the signal being received (only when I run siint from terminal.. from php it blunders).

 

    $pid = `pgrep ex`; // this line doesn't work atm so I have $pid set by hand to the process of the c/c++ program

    $y = `kill -10 $pid`;

    system("kill -10 $pid", $x);

    exec("./sendsig");

 

Is the direct route I tried getting php to send the signal itself, and that didn't work at all.

 

Does anyone have any ideas? I'm running out of options to get php to send a signal to a program.

[JonnoTheDev]

exec should work as long as you are using the full correct path.

exec('/path/program', $output);

 

Also has your CLI program got the appropriate permissions for php to execute it?

 

If you are on a shared host then they may have disabled the use of exec().

[moejoe22]

Yes, I can use system, exec to run simple commands like echo or execute simple scripts. I think the problem is that the c/c++ program has different ownership while the php has ownership of apache.. I don't know how to get apache to send a signal to a program that it doesn't own.

[DarkWater]

Are the shell scripts really in the same folder as your PHP script?  You have ./ in front of the path, which would mean that it HAS to be in the same folder or deeper.  If it's in like, ~/bin, then use a full path or hope that you have nothing else with the same name in your PATH.

[moejoe22]

Yep same folder, I will move later for security reasons.. now I just want them to work.

[DarkWater]

What OS are you running?  It's very strange that this isn't working for you, because I just tried pgrep from PHP and it worked just fine.  Maybe it's some php.ini setting that I don't know about, but idk.  Do you have access to your php.ini?

[moejoe22]

It's a linux server, I don't know the version.. I also don't own the server.

 

Yes, I have it, which setting would you like to view?

[DarkWater]

safe_mode and safe_mode_exec_dir.

[moejoe22]

safe_mode Off Off

safe_mode_exec_dir no value no value

[DarkWater]

That's weird then.  I'll get back to you tomorrow; I need to go.

[JonnoTheDev]

Make sure the program file has the correct permissions. Doesnt matter about ownership.

Use chmod.

[moejoe22]

Yea, it has +x permissions.