Use file_put_contents without removing the contents in it?

I want to put stuff into a file when typing a command but it always removes the content which is in it. How can I just leave the content there and put the new one in a new line?

PHP:

file_put_contents($file,file_get_contents($file) . $data);

Or you can use fopen, fwrite, and fclose with the append flag.

Thanks!

I did not know that existed.