TH DUP 2
SH NAME
dup \- duplicate an open file descriptor
SH SYNOPSIS
B #include <u.h>
br
B #include <libc.h>
PP
B
int dup(int oldfd, int newfd)
SH DESCRIPTION
Given a file descriptor,
IR oldfd ,
referring to an open file,
I dup
returns a new file descriptor referring to the same file.
PP
If
I newfd
is \-1 the system chooses the lowest available file descriptor.
Otherwise,
I dup
will use
I newfd
for the new file descriptor
(closing any old file associated with
IR newfd ).
File descriptors are allocated dynamically,
so to prevent unwarranted growth of the file descriptor table,
I dup
requires that
I newfd
be no greater than 20 more than the highest file descriptor ever used by
the program.
SH SOURCE
B /sys/src/libc/9syscall
SH SEE ALSO
IR intro (2),
IR dup (3)
SH DIAGNOSTICS
Sets
IR errstr .

You are viewing proxied material from sdf.org. The copyright of proxied material belongs to its original authors. Any comments or complaints in relation to proxied material should be directed to the original authors of the content concerned. Please see the disclaimer for more details.