alt Hacker News> The whole issue is specific to C and languages that copied C or use its runtime underneath in implementations (like Python)
So it's "specific to" almost all programming languages in actual use. That's a rather esoteric point.
> For reference, Unix has no API other than bytes either.
Unix does offer an API for writing C-standard in-memory text strings to Unix-standard on-disk text files, it just happens to be the same one as the API for writing in-memory binary strings to on-disk binary files.
> Unix does offer an API for writing C-standard in-memory text strings
Why on bloody Earth should a presumably generic-purpose OS provide a special API for dealing with internal representation of some data structure in a (particular) implementation of a (particular) programming language?
Besides, it doesn't offer such an API anyhow; you need to take care to manually pass the result of a strlen() call instead of sizeof()'s as the value for the len parameter of a write() call, otherwise a NUL-terminator will get written into the file as well.
And C says nothing about what constitutes a line break, by the way. Nor does it have any concept of a "line", or any utilities for working with lines specifically, it only knows of strings, and that's all. The concept of "text line" is POSIX.