NAME

dup − duplicate an open file descriptor

SYNOPSIS

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 in the range of legal file descriptors ­dup will use that for the new file descriptor (closing any old file associated with newfd); if ­newfd is −1 the system chooses the lowest available file descriptor. 

SEE ALSO

intro(2), dup(3)

DIAGNOSTICS

Sets ­errstr. 

Plan 9  —  January 03, 1993