workbench/network/stacks/AROSTCP/netlib/_dup2.c

   1 /* $Id$
   2  *
   3  *      _dup2.c - duplicate a file descriptor (SAS/C)
   4  *
   5  *      Copyright © 1994 AmiTCP/IP Group,
   6  *                       Network Solutions Development Inc.
   7  *                       All rights reserved.
   8  */
   9
  10 #include <ios1.h>
  11 #include <fcntl.h>
  12 #include <stdlib.h>
  13 #include <dos.h>
  14 #define USE_BUILTIN_MATH
  15 #include <string.h>
  16 #include <errno.h>
  17 #include <dos/dos.h>
  18 #include <proto/dos.h>
  19
  20 #include <bsdsocket.h>
  21
  22 /****** net.lib/dup2 **********************************************************
  23     SEE ALSO
  24         dup()
  25 *******************************************************************************
  26 */
  27
  28
  29 int
  30 __dup2(int old_fd, int new_fd)
  31 {
  32   struct UFB *ufb;
  33   int ufbflg;
  34
  35   /*
  36    * Check if there is nothing to do
  37    */
  38   if (old_fd == new_fd)
  39     return old_fd;
  40
  41   /*
  42    * Check for the break signals
  43    */
  44   __chkabort();
  45
  46   __close(new_fd);
  47
  48   /*
  49    * Find the ufb * for the old FD
  50    */
  51   if ((ufb = __chkufb(old_fd)) == NULL) {
  52     errno = EBADF;
  53     return -1;
  54   }
  55
  56   ufbflg = ufb->ufbflg;
  57
  58   /*
  59    * The brain dead UFB system won't allow duplicating ordinary files
  60    */
  61   if ((ufbflg & UFB_SOCK) == UFB_SOCK) {
  62     return Dup2Socket(old_fd, new_fd);
  63   } else {
  64     errno = EBADF;
  65     return -1;
  66   }
  67
  68 }