PHP New Line will not work

Question

Hi I am trying to create some code that first reads the existing contents of the file in and then adds the new line of code on a new line but the code i am using just adds i

Answer 1

Line endings per OS

Unix / Linux
\n

DOS / Windows
\r\n

Invalid
\r and \n\r

The value of PHP_EOL constant depends on the platform php is running on.
It doesn't detect the line-endings in the current file or anything magic.