Function getline 

pub unsafe extern "C" fn getline(
    __lineptr: *mut *mut c_char,
    __n: *mut usize,
    __stream: *mut FILE,
) -> __ssize_t

Like `getdelim’, but reads up to a newline.

This function is not part of POSIX and therefore no official cancellation point. But due to similarity with an POSIX interface or due to the implementation it is a cancellation point and therefore not marked with __THROW.