i'm trying to make a php code that return the result of graph.facebook.com/facebook_page

i'm trying to make a php code that return the result of
graph.facebook.com/facebook_page

I'm trying to to make a php code that return the ID of the page when I do
graph.facebook.com/facebook_page
For example I have a my_file.txt file that contain the facebook pages that
I want to get the code of them.
I know the code of looping inside my_file.txt
<?php
$lines = file('my_file.txt');
foreach ($lines as $line)
{
echo htmlspecialchars($line) . '<br>';
}
?>
but I can't find a way to return the ID of each page in the txt file.