Question

Is is possible for a php script to know if another script calls it via require or require_once?

eg:

if scripta.php calls me do xyz;
if scriptb.php calls me do abc;

Edit: Thanks for your suggestions guys. It was more of a what if question, rather than an actual problem. I realise I could set a variable, $caller and update it when I made the require statement. I just wondered if there was another way to do this in the file that’s being called 🙂

Answer 1

If you just want to check if the your file was included or not:

$_SERVER['SCRIPT_FILENAME'] will always return the filename of the script that has been originally called. (e.g. “start.php”)

The constant __FILE__ will always return the true file name of the script that it is used in. (e.g. “library.inc.php”)

So you can do something like this:

if ($_SERVER['SCRIPT_FILENAME'] !== __FILE__) {
    echo "script was included!";
}
else {
    echo "script was called directly!";
}

If you want to distinguish from where the file has been included:

$include_from = get_included_files();
if (count($include_from) > 1) {
    $include_from = $include_from[count($include_from)-2];
}
else {
    $include_from = $include_from[0];
}
switch ($include_from) {
    case __FILE__:
        // not included, called directly
        break;
    case "/path/to/scripta.php":
        // do abc
        break;
    case "/path/to/scriptb.php": 
        // do xyz
        break;
    default:
        // do other stuff
        break;
}