adtools/clib2

/*
 * $Id: stdio_duplicate_fd.c,v 1.6 2006-10-10 13:39:26 obarthel Exp $
 *
 * :ts=4
 *
 * Portable ISO 'C' (1994) runtime library for the Amiga computer
 * Copyright (c) 2002-2015 by Olaf Barthel <obarthel (at) gmx.net>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Neither the name of Olaf Barthel nor the names of contributors
 *     may be used to endorse or promote products derived from this
 *     software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _STDIO_HEADERS_H
#include "stdio_headers.h"
#endif /* _STDIO_HEADERS_H */

/****************************************************************************/

void
__duplicate_fd(struct fd * duplicate_fd,struct fd * original_fd)
{
    assert( duplicate_fd != NULL && original_fd != NULL );

    __fd_lock(original_fd);

    /* Initialize the duplicate to match the original. */
    __initialize_fd(duplicate_fd,original_fd->fd_Action,original_fd->fd_DefaultFile,original_fd->fd_Flags,original_fd->fd_Lock);

    /* Figure out where the linked list of file descriptors associated
       with this one starts. */
    if(original_fd->fd_Original != NULL)
        duplicate_fd->fd_Original = original_fd->fd_Original;
    else
        duplicate_fd->fd_Original = original_fd;

    /* Add the duplicate at the beginning of the list. */
    duplicate_fd->fd_NextAlias                = duplicate_fd->fd_Original->fd_NextAlias;
    duplicate_fd->fd_Original->fd_NextAlias    = duplicate_fd;

    __fd_unlock(original_fd);
}