How to call PHP function using web service?

Question

I write PHP function in abc.php, it is like this,

function testFunction($par1, $par2){
    echo $par1." ".$par2;
}

Now I am trying to access above function via web services, how to do that, I tried using "CURL" but it seems not success. please help me,

$ch = curl_init();
$curlConfig = array(
    CURLOPT_URL            => "abc.php",
    CURLOPT_POST           => false,
    CURLOPT_RETURNTRANSFER => true,

);
curl_setopt_array($ch, $curlConfig);
$result = curl_exec($ch);
curl_close($ch);