$keyword = stackoverflow;
foreach(array(co,net,org,info,us,ca,biz,me,mobi,tv,ws,asia,cc,la,xxx) as $tld )
 if (checkdnsrr($keyword.'.'.$tld, 'A')){
    echo 'taken<br>';
 }else{
    echo 'available<br>';
 }
       
$tlds = array(co,net,org,info,us,ca,biz,me,mobi,tv,ws,asia,cc,la,xxx);
    $numberOFtlds = count($tlds);
    $tldResults = array();
 
    function doesDomainExists($keyword,$tld){
       if (checkdnsrr($keyword.'.'.$tld, 'A')){
          //echo 'taken<br>';
          $tldResults[$tld] = taken;
       }else{
          $tldResults[$tld] = available;
       }
    }
 
 
    // where the function is to be run asynchronously
 
 
    $finished = false;
    while ( ! $finished ):
    $number_of_results = count($tldResults);
    if ( $tldResults == $numberOFtlds ):
       $finished = true;          
       endif;
    endwhile;
       
<?
 
function getSession(){
$now = new DateTime(null, new DateTimeZone('America/New_York'));
$i = $now->format('Y-m-d H:i:s');
return md5($i);
}
 
function countlines($lookupID){
$lines = file('factory/'.$lookupID.'/results.txt');
return count($lines);
}
 
function startScript($keyword,$tld){
fopen('factory/$lookupID/'.$tld.'.php?keyword='.$keyword.'&tld='.$tld, 'a+');
}
 
 
 
// get keyword
$keyword = 'stackoverflow';
 
// set array of tlds
$tlds = array(co,net,org,info,us,ca,biz,me,mobi,tv,ws,asia,cc,la,xxx);
 
 
// get loop up id
$lookupID = getSession();
 
// create temporary factory room
mkdir('factory/'.$lookupID, 0777, true);
 
// fill factory room with scripts
$toolScript = ('<? ignore_user_abort(true); $k = $_GET["keyword"]; $t = $_GET["tld"]; function tofile($content) { file_put_contents("results.txt", $content."n", FILE_APPEND | LOCK_EX); } if (checkdnsrr("$k.$t", "A")){ tofile("$t|taken"); }else{ tofile("$t|available"); } ?>');
foreach($tlds as $tool) file_put_contents('factory/'.$lookupID.'/'.$tool.'.php', $toolScript);
 
// initiate while server
    file_put_contents('factory/'.$lookupID.'/results.txt', '');
    $number_of_tlds = count($tlds);
    $finished = false;
    while (!$finished):
    if (countlines($lookupID) == $number_of_tlds):
       $finished = true;
       echo done;          
       endif;
    endwhile;
 
    // where the function is to be run asynchronously
    foreach ($tlds as $tld) {
       startScript($keyword,$tld);
    }