sysdeps/mach/hurd/pipe.c

   1 /* Copyright (C) 1992-2015 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, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <sys/socket.h>
  20 #include <sys/stat.h>
  21 #include <unistd.h>
  22
  23 /* Create a one-way communication channel (pipe).
  24    Actually the channel is two-way on the Hurd.
  25    If successful, two file descriptors are stored in FDS;
  26    bytes written on FDS[1] can be read from FDS[0].
  27    Returns 0 if successful, -1 if not.  */
  28 int
  29 __pipe (int fds[2])
  30 {
  31   int save_errno = errno;
  32   int result;
  33
  34   /* The magic S_IFIFO protocol tells the pflocal server to create
  35      sockets which report themselves as FIFOs, as POSIX requires for
  36      pipes.  */
  37   result = __socketpair (PF_LOCAL, SOCK_STREAM, S_IFIFO, fds);
  38   if (result == -1 && errno == EPROTONOSUPPORT)
  39     {
  40       /* We contacted an "old" pflocal server that doesn't support the
  41          magic S_IFIFO protocol.
  42          FIXME: Remove this junk somewhere in the future.  */
  43       __set_errno (save_errno);
  44       return __socketpair (PF_LOCAL, SOCK_STREAM, 0, fds);
  45     }
  46
  47   return result;
  48 }
  49 libc_hidden_def (__pipe)
  50 weak_alias (__pipe, pipe)