DUP(2) DUP(2)
NAME
dup, dup2 - duplicate an open file descriptor
SYNOPSIS
int dup(fildes)
int fildes;
int dup2(fildes, fildes2)
int fildes, fildes2;
DESCRIPTION
Given a file descriptor dup allocates another file descrip-
tor synonymous with the original. The new file descriptor
is returned.
In dup2, fildes is a file descriptor referring to an open
file, and fildes2 is an integer in the range of legal file
descriptors. Dup2 causes fildes2 to refer to the same file
and returns fildes2. If fildes2 already referred to another
open file, it is closed first.
SEE ALSO
open(2), pipe(2), fd(4)
DIAGNOSTICS
EBADF, EMFILE
BUGS
Dup of a file descriptor greater than 63 turns into a dup2
with a random second argument.