How to read a large file line by line?

Question

I want to read a file line by line, but without completely loading it in memory.

My file is too large to open in memory, and if try to do so I always get out of memo

Answer 1

if ($file = fopen("file.txt", "r")) {
    while(!feof($file)) {
        $line = fgets($file);
        # do same stuff with the $line
    }
    fclose($file);
}