70 lines
1.7 KiB
C
70 lines
1.7 KiB
C
/* dup2.c
|
|
The Unix dup2 function, for systems which only have dup.
|
|
|
|
Copyright (C) 1985, 1986, 1987, 1988, 1990 Free Software Foundation, Inc.
|
|
|
|
This file is part of the Taylor UUCP package.
|
|
|
|
This program is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU General Public License as
|
|
published by the Free Software Foundation; either version 2 of the
|
|
License, or (at your option) any later version.
|
|
|
|
This program 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
|
|
General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, write to the Free Software
|
|
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
|
|
|
The author of the program may be contacted at ian@airs.com or
|
|
c/o Infinity Development Systems, P.O. Box 520, Waltham, MA 02254.
|
|
*/
|
|
|
|
#include "uucp.h"
|
|
#include "sysdep.h"
|
|
|
|
#include <errno.h>
|
|
|
|
#if HAVE_FCNTL_H
|
|
#include <fcntl.h>
|
|
#else
|
|
#if HAVE_SYS_FILE_H
|
|
#include <sys/file.h>
|
|
#endif
|
|
#endif
|
|
|
|
/* I basically took this from the emacs 18.57 distribution, although I
|
|
cleaned it up a bit and made it POSIX compliant. */
|
|
|
|
int
|
|
dup2 (oold, onew)
|
|
int oold;
|
|
int onew;
|
|
{
|
|
if (oold == onew)
|
|
return onew;
|
|
(void) close (onew);
|
|
|
|
#ifdef F_DUPFD
|
|
return fcntl (oold, F_DUPFD, onew);
|
|
#else
|
|
{
|
|
int onext, oret, isave;
|
|
|
|
onext = dup (oold);
|
|
if (onext == onew)
|
|
return onext;
|
|
if (onext < 0)
|
|
return -1;
|
|
oret = dup2 (oold, onew);
|
|
isave = errno;
|
|
(void) close (onext);
|
|
errno = isave;
|
|
return oret;
|
|
}
|
|
#endif
|
|
}
|