What are the best practices for integrating external scripts, such as Perl, with PHP to ensure proper functionality?

When integrating external scripts like Perl with PHP, it is important to use the appropriate functions to execute the external script and capture its output. One common approach is to use the `exec()` function in PHP to run the Perl script and retrieve the output. It is also crucial to properly sanitize any user input passed to the Perl script to prevent security vulnerabilities.

$perlScript = 'path/to/your/perl/script.pl';
$userInput = $_POST['user_input']; // Assuming user input is passed to the Perl script

// Sanitize user input before passing it to the Perl script
$sanitizedInput = escapeshellarg($userInput);

// Execute the Perl script and capture its output
$output = exec("perl $perlScript $sanitizedInput");

// Do something with the output
echo $output;