Source: http://ie2.php.net/manual/en/function.fgets.php#113113
Regarding Leigh Purdie's comment (from 4 years ago) about stream_get_line being better for large files, I decided to test this in case it was optimized since then and I found out that Leigh's comment is just completely incorrect
fgets actually has a small amount of better performance, but the test Leigh did was not set up to produce good results.
The suggested test was: