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

/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