> O_APPEND is just redundant (because by definition if you truncate the file you're writing at its end). No, O_APPEND is not redundant with O_TRUNC. When you u

> O_APPEND is just redundant (because by definition if you truncate the file you're writing at its end). No, O_APPEND is not redundant with O_TRUNC. When you use O_APPEND, you also have the extra behavior that every write goes to the end of the file, instead of the current position; this is important when more than one process is writing to the same file.