how can i fix this get query string?

Question

the code

<?php

$_SERVER['QUERY_STRING'];


$text = $_SERVER['QUERY_STRING'];
$var_str = var_export($text, true);
$var = "<?php\n\n\$text = $var_str;\n\n?>";
file_put_contents('testnew.php', $var);

echo $text;

 ?>

what i want to do is get query-string from the url and store it in a php file testnew.php

http://test.com/query.php?asdawdawd

note i am very beginner

edit: now the get query string part is working after @tim suggestion but it still doesn't write the query-string to the file

Answer 1

the working code

<?php

$text = $_SERVER['QUERY_STRING'];
$file = fopen("testnew.txt","ab");
fwrite($file,$text."\n");
fclose($file);


echo $text;

 ?>

edit : as @tim suggested i don't need the line $_SERVER['QUERY_STRING'];

so i removed it from the code .

edit 2 : as i asked @tim about

how can i make it type in a new line like using this fwrite($file,$text \n); but it doesn't work

so he gave me the working one fwrite($file,$text."\n"); and i replaced the old one from the code with it fwrite($file,$text);