NAME

	dup – duplicate an open file descriptor

SYNOPSIS

	#include <u.h> #include <libc.h> int dup(int oldfd, int newfd)

DESCRIPTION

	Given a file descriptor, oldfd, referring to an open file, dup returns a new file descriptor referring to the same file. If newfd is –1 the system chooses the lowest available file descriptor. Otherwise, dup will use newfd for the new file descriptor (closing any old file associated with newfd).

SOURCE

	/usr/local/plan9/src/lib9/dup.c

DIAGNOSTICS

	Sets errstr.

BUGS

	To avoid name conflicts with the underlying system, dup is a preprocessor macro defined as p9dup; see intro(3).