sysdeps/mach/hurd/pipe.c

   1 /* Copyright (C) 1992,93,94,95,96,99,2000,2002 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <errno.h>
  20 #include <sys/socket.h>
  21 #include <sys/stat.h>
  22 #include <unistd.h>
  23
  24 /* Create a one-way communication channel (pipe).
  25    Actually the channel is two-way on the Hurd.
  26    If successful, two file descriptors are stored in FDS;
  27    bytes written on FDS[1] can be read from FDS[0].
  28    Returns 0 if successful, -1 if not.  */
  29 int
  30 __pipe (int fds[2])
  31 {
  32   int save_errno = errno;
  33   int result;
  34
  35   /* The magic S_IFIFO protocol tells the pflocal server to create
  36      sockets which report themselves as FIFOs, as POSIX requires for
  37      pipes.  */
  38   result = __socketpair (PF_LOCAL, SOCK_STREAM, S_IFIFO, fds);
  39   if (result == -1 && errno == EPROTONOSUPPORT)
  40     {
  41       /* We contacted an "old" pflocal server that doesn't support the
  42          magic S_IFIFO protocol.
  43          FIXME: Remove this junk somewhere in the future.  */
  44       __set_errno (save_errno);
  45       return __socketpair (PF_LOCAL, SOCK_STREAM, 0, fds);
  46     }
  47
  48   return result;
  49 }
  50 libc_hidden_def (__pipe)
  51 weak_alias (__pipe, pipe)