https://phpstudy.connpass.com/event/286669/
# Spec
https://pubs.opengroup.org/onlinepubs/9699919799
> ### 3.403 Text File
>
> A file that contains characters organized into zero or more lines. (略)
---
> ### 3.206 Line
>
> A sequence of zero or more non- \ characters plus a terminating \ character.
