Embedding PHP inside PHP

Question

I have recently put up a server, and I am making changes gradually. One of the changes is the contents of a php page. I commonly use a php "shell" (just a textarea and the php just evals what is written). I have made some changes and want to use

fwrite($file, "<?php php here ?>");

but i am getting an error. I believe I know the problem, and it is because i have nested php like

<?php
$a = fopen('../php.php', 'w');
fwrite($a, "
<?php
eval($_POST['phptorun']);
?>
");
fclose($a);
?>

Is there any way I can get it to just put that php code into the file php.php?

The error i was getting is:

Parse error: syntax error, unexpected '' (T_ENCAPSED_AND_WHITESPACE), expecting identifier (T_STRING) or variable (T_VARIABLE) or number (T_NUM_STRING) in /var/www/html/Tyler/replace.php on line 5

Edit:

I forgot to say a couple of things. The server is a LAMP (Linux Apache MySQL PHP), running on my Raspberry Pi 2, model B. If you want to visit my server, it is at 71.204.114.18

Answer 1

Try to escape the $ symbol:

<?php
$a = fopen('../php.php', 'w');
fwrite($a, "
<?php
eval(\$_POST['phptorun']);
?>
");
fclose($a);
?>