What do the dup() and dup2() system calls really do? How would I use them in practice?
What do the dup() and dup2() system calls really do? How would I use
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What do the dup() and dup2() system calls really do? How would I use them in practice?
Both make a new file descriptor corresponding to an existing open file description. Most properties between the old and new fd (like position) are shared; the only property I can think of that’s not shared is the close-on-exec flag. The difference between
dupanddup2is thatdupassigns the lowest available file descriptor number, whiledup2lets you choose the file descriptor number that will be assigned and atomically closes and replaces it if it’s already taken.