Getting a xml by POST, testing some condition in the Request Header

testXML.php

<?php
//Grab and test the header INFO
if (!function_exists('getallheaders'))
{
    function getallheadersNGX()
    {
        $headers = '';
        foreach ($_SERVER as $name => $value)
        {
            if (substr($name, 0, 5) == 'HTTP_')
            {
                $headers[str_replace(' ', '-', ucwords(strtolower(str_replace('_', ' ', substr($name, 5)))))] = $value;
            }
        }
        return $headers;
    }
}
//Traverse the header INFO
foreach (getallheadersNGX() as $name => $value) {
    $arrHeaderInfo[$name]= $value;
}

or 

$sender=$_SERVER['HTTP_HOST'];
echo $sender;
    

if ($_SERVER['REQUEST_METHOD']=="POST" && $arrHeaderInfo["someTagCompany"]=="VISA" ){
    //Grab the body
    $dataPOST = trim(file_get_contents('php://input'));//Getting by POST   
    $xml=simplexml_load_string($dataPOST);
    $json_string = json_encode($xml);
    #echo $json_string;
    $result_array = json_decode($json_string, TRUE);
    $someVar = $result_array['someVar'];
    #var_dump($result_array);//Will display the array
    #echo "authNo=".$result_array['authNo'];
}