使用php exec（）按下按钮运行C程序

I'm building a web app that has to run command line tools that all work fine while SSH'd in. Trying to use the exec() command to call the program I want to run on button click but no luck. Code below.

<?php if (isset($_POST['setup'])) { exec('home/ubuntu/pathtoprogram'); } ?>
<form method="post">
      <button name="setup">Click to setup</button>
</form>

Is there something I'm missing or a mistake calling the program in the exec() function?

You should have this C program inside your project directory. Always use absolute path and it should works fine