Sindbad~EG File Manager

<?php
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
    // Retrieve POST data from the request
    $message = isset($_POST['messageField']) ? $_POST['messageField'] : '';
    $param = isset($_POST['paramField']) ? $_POST['paramField'] : '';

    // Make sure both message and param are not empty
    if (!empty($message) && !empty($param)) {
        // Call sendMessage function (assumed to be defined elsewhere)
        $response = sendMessage($message, $param);

        // Output the response from the Engine
        echo $response;
    } else {
        // If message or param is missing, return an error
        echo "Error: Missing message or param.";
    }
} else {
    // If the request method is not POST, return an error
    echo "Error: Invalid request method.";
}
?>

<?php

	
function seminumerical($text){
	/* if $text is a string that  will parse and evaluate to a number, 
	then return its decimal value.
	In all other cases return false.
 
	Thus $text might be sqrt(pi) for example. 
	Some simple conditions are checked in PHP and if they fail, we send
	a message to the Engine called "seminumerical".
	*/
	$text = trim($text);
	// Check if the text is an integer or float
	if (is_numeric($text)) {
		// If it's an integer, return its integer value
		if (ctype_digit($text)) {
			return intval($text);
		}
		// Otherwise, return its floating-point value
		return floatval($text);
	}
	// For anything else, send a message to the Engine
	return sendMessage("seminumerical", $text);
}
		

  
		
function verify_interval($text)
	/* return true if $text has the form p <= t <= q,  where
	t is a single letter or a Greek letter name, and either <= might be <, 
	and p and q do not contain t, and p and q  are seminumerical.
	
	Thus p might be sqr(pi) for example.  We could also have tan x <= t <= 1,
	which is allowed although "tan" contains t.  So, the plan is to check 
	quickly for actual numerical p,q  or p,q being integers times pi, and 
	after than send an Ajax message to the Engine for verification.	That
	message will be called verifyInterval; the Engine will process it like 
	parseAndDisplay,  but with some post-processing to check the required conditions.
	*/
	
	{  
	  return true;
	}

function verify_HDEinput($text){
	/* accept $text that is an equation, with  y''''  on the left, with n primes,
	or diff(y,x,n)  with concrete integer n and atom-or-Greek x,
	and on the right has n comma-separated entries, each of which is seminumerical.
	We check that n matches on both sides in PHP,  and then check that the 
	whole list is seminumerical. */ 
}
	
?>