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oldlinux-files/gnu/glibc/glibc-1.05.tar/glibc-1.05/sysdeps/mach/hurd/__dup.c
2024-02-19 00:24:47 -05:00

71 lines
2.1 KiB
C

/* Copyright (C) 1991, 1992 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <ansidecl.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <hurd.h>
/* Duplicate FD, returning a new file descriptor open on the same file. */
int
DEFUN(__dup, (fd), int fd)
{
int new;
int dealloc, dealloc_ctty;
io_t port, ctty;
int flags;
int dealloc_dt;
struct _hurd_fd_user d;
/* Extract the ports and flags from FD. */
d = _hurd_fd (fd, &dealloc_dt);
if (d.d == NULL)
{
badf:
errno = EBADF;
return -1;
}
flags = d.d->flags;
ctty = _hurd_port_get (&d.d->ctty, &dealloc_ctty);
port = _hurd_port_locked_get (&d.d->port, &dealloc); /* Unlocks D.d. */
if (port == MACH_PORT_NULL)
goto badf;
/* Get a new descriptor. */
new = _hurd_dalloc (port, ctty, flags);
if (new >= 0)
{
/* Give the ports each a user ref for the new descriptor. */
__mach_port_mod_refs (__mach_task_self (), port,
MACH_PORT_RIGHT_SEND, 1);
if (ctty != MACH_PORT_NULL)
__mach_port_mod_refs (__mach_task_self (), ctty,
MACH_PORT_RIGHT_SEND, 1);
}
_hurd_port_free (&d->port, port, &dealloc);
if (ctty != MACH_PORT_NULL)
_hurd_port_free (&d->ctty, ctty, &dealloc_ctty);
_hurd_fd_done (d, &dealloc_dt);
return new;
}