file_get_contents（）无法读取PHP标记<?php ?>

Question

I am using cakePHP and got stuck with this riddle. Time ago i made function that inserts custom routes dynamically in file using file_get_contents() and string replace functions.

$filename = "301routes.php";
$path = SERVER_PUBLIC_PATH . 'app' . DS . 'config';
$add_data = "Router::connect('".$old."', array('controller'=>'index_router', 'action'=>'redirect_301','".$new."'));\n";
$file_data = file_get_contents($path . DS . $filename);
$file_data = str_replace("<?php\n","<?php\n".$add_data,$file_data);
file_put_contents($path . DS . $filename, $file_data);

this worked, but now i tried to put exactly the same function in other project and its working only when there is no PHP tag. Problem is with file_get_contents() function becouse it reads file well when content is:

// routes here
Router::connect('/articles/category/en/test', array('controller'=>'index_router', 'action'=>'redirect_301','/articles/category/en/test-old'));

but when i change beginning like this

<?php
Router::connect('/articles/category/en/test', array('controller'=>'index_router', 'action'=>'redirect_301','/articles/category/en/test-old'));
?>

file_get_contents() returns only part of file:

string(154) "'index_router', 'action'=>'redirect_301','/articles/category/en/test-old')); ?>"

Can someone help me with this?

Answer 1

To run php codes and assign to $file_data variable,

ob_start();
$file_data = file_get_contents($path . DS . $filename);
ob_end_flush();

Answer 2

Try: Create new file 301routes.php in config directory then read write permission of file.
$filename = "301routes.php";
$path =  __DIR__;
$add_data = "Router::connect('".$old."', array('controller'=>'index_router', 'action'=>'redirect_301','".$new."'));\n";
$file_data = file_get_contents($path . DS . $filename);
$file_data = str_replace("<?php\n","<?php\n".$add_data,$file_data);
file_put_contents($path . DS . $filename, $file_data);