DUP(3) DUP(3) 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 intro(3).