Julia Evans on Nostr: does anyone know why in libc output to pipes and files is “fully buffered” ...

does anyone know why in libc output to pipes and files is “fully buffered” instead of line buffered? (output to a tty is line buffered)

I imagine it’s a Performance Thing but also it’s really annoying sometimes, like when you’re piping to ‘grep’

(only interested in explanations of *why* libc behaves this way, not *what* libc is doing)