What are the recommended methods for handling input variables in a Perl script that is being executed from PHP?

When executing a Perl script from PHP and passing input variables, it is recommended to properly sanitize and validate the input to prevent security vulnerabilities such as code injection. One way to handle input variables is to use PHP's `escapeshellarg()` function to escape the variables before passing them to the Perl script. This function ensures that the input is safe to be used in a shell command.

$input_variable = "user_input_here";
$escaped_input = escapeshellarg($input_variable);
$perl_script = "/path/to/perl_script.pl";
$output = shell_exec("perl $perl_script $escaped_input");
echo $output;