Analysis of PHP fwrite write txt file when using \ r \ n can not wrap the problem _php skills

Today encountered a problem is to write TXT file with Fwrite when the RN can not wrap
Tried for a long time did not find a way!
All of a sudden think of a dongdong before the book to see the later or with this dongdong to solve!
Now write to prevent future forget also hope to help the need to help friends!
Look directly at the code:

Copy Code code as follows:

<?php
$stream = fopen ("robots.txt", "w+");
Fwrite ($stream, "Did you change the line? \ r \ n I've changed the line!");
?>