Use Gnulib forkpty()

1 files changed, 108 insertions, 0 deletions

diff --git a/lib/posix_openpt.c b/lib/posix_openpt.c
new file mode 100644
index 00000000..92eec2e9
--- /dev/null
+++ b/lib/posix_openpt.c
@@ -0,0 +1,108 @@
+/* Open the master side of a pseudo-terminal.
+   Copyright (C) 2010-2014 Free Software Foundation, Inc.
+
+   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 3 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, see <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <stdlib.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#if defined __OpenBSD__
+# include <sys/ioctl.h>
+# include <sys/tty.h>
+#endif
+
+/* posix_openpt() is already provided on
+     glibc >= 2.2.1 (but is a stub on GNU/Hurd),
+     Mac OS X >= 10.4,
+     FreeBSD >= 5.1 (lived in src/lib/libc/stdlib/grantpt.c before 8.0),
+     NetBSD >= 3.0,
+     AIX >= 5.2, HP-UX >= 11.31, Solaris >= 10, Cygwin >= 1.7.
+   Thus, this replacement function is compiled on
+     Mac OS X 10.3, OpenBSD 4.9, Minix 3.1.8,
+     AIX 5.1, HP-UX 11.23, IRIX 6.5, OSF/1 5.1, Solaris 9,
+     Cygwin 1.5.x, mingw, MSVC 9, Interix 3.5, BeOS.
+   Among these:
+     - AIX has /dev/ptc.
+     - HP-UX 10..11, IRIX 6.5, OSF/1 5.1, Solaris 2.6..9, Cygwin 1.5
+       have /dev/ptmx.
+     - HP-UX 10..11 also has /dev/ptym/clone, but this should not be needed.
+     - OpenBSD 4.9 has /dev/ptm and the PTMGET ioctl.
+     - Minix 3.1.8 have a list of pseudo-terminal devices in /dev.
+     - On native Windows, there are no ttys at all.  */
+
+int
+posix_openpt (int flags)
+{
+  int master;
+
+#ifdef _AIX /* AIX */
+
+  master = open ("/dev/ptc", flags);
+
+#elif (defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__ /* mingw */
+
+  /* Mingw lacks pseudo-terminals altogether.  */
+  master = -1;
+  errno = ENOSYS;
+
+#elif defined __OpenBSD__
+
+  /* On OpenBSD, master and slave of a pseudo-terminal are allocated together,
+     by opening /dev/ptm and applying the PTMGET ioctl to it.  */
+  int fd;
+  struct ptmget data;
+
+  fd = open (PATH_PTMDEV, O_RDWR);
+  if (fd >= 0)
+    {
+      if (ioctl (fd, PTMGET, &data) >= 0)
+        {
+          master = data.cfd;
+          close (data.sfd);
+          close (fd);
+        }
+      else
+        {
+          int saved_errno = errno;
+          close (fd);
+          errno = saved_errno;
+          master = -1;
+        }
+    }
+  else
+    master = -1;
+
+#else /* Mac OS X, Minix, HP-UX, IRIX, OSF/1, Solaris 9, Cygwin 1.5 */
+
+  /* Most systems that lack posix_openpt() have /dev/ptmx.  */
+  master = open ("/dev/ptmx", flags);
+
+  /* If all this does not work, we could try to open, one by one:
+     - On Mac OS X: /dev/pty[p-w][0-9a-f]
+     - On *BSD:     /dev/pty[p-sP-S][0-9a-v]
+     - On Minix:    /dev/pty[p-q][0-9a-f]
+     - On AIX:      /dev/ptyp[0-9a-f]
+     - On HP-UX:    /dev/pty[p-r][0-9a-f]
+     - On OSF/1:    /dev/pty[p-q][0-9a-f]
+     - On Solaris:  /dev/pty[p-r][0-9a-f]
+   */
+
+#endif
+
+  return master;
+}