1 files changed, 78 insertions, 0 deletions
diff --git a/lib/portage/util/_pty.py b/lib/portage/util/_pty.py
new file mode 100644
index 000000000..11c8b92af
--- /dev/null
+++ b/lib/portage/util/_pty.py
@@ -0,0 +1,78 @@
+# Copyright 2010-2011 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+
+import platform
+import pty
+import termios
+
+from portage import os
+from portage.output import get_term_size, set_term_size
+from portage.util import writemsg
+
+# Disable the use of openpty on Solaris as it seems Python's openpty
+# implementation doesn't play nice on Solaris with Portage's
+# behaviour causing hangs/deadlocks.
+# Additional note for the future: on Interix, pipes do NOT work, so
+# _disable_openpty on Interix must *never* be True
+_disable_openpty = platform.system() in ("SunOS",)
+
+_fbsd_test_pty = platform.system() == 'FreeBSD'
+
+def _create_pty_or_pipe(copy_term_size=None):
+	"""
+	Try to create a pty and if then fails then create a normal
+	pipe instead.
+
+	@param copy_term_size: If a tty file descriptor is given
+		then the term size will be copied to the pty.
+	@type copy_term_size: int
+	@rtype: tuple
+	@return: A tuple of (is_pty, master_fd, slave_fd) where
+		is_pty is True if a pty was successfully allocated, and
+		False if a normal pipe was allocated.
+	"""
+
+	got_pty = False
+
+	global _disable_openpty, _fbsd_test_pty
+
+	if _fbsd_test_pty and not _disable_openpty:
+		# Test for python openpty breakage after freebsd7 to freebsd8
+		# upgrade, which results in a 'Function not implemented' error
+		# and the process being killed.
+		pid = os.fork()
+		if pid == 0:
+			pty.openpty()
+			os._exit(os.EX_OK)
+		pid, status = os.waitpid(pid, 0)
+		if (status & 0xff) == 140:
+			_disable_openpty = True
+		_fbsd_test_pty = False
+
+	if _disable_openpty:
+		master_fd, slave_fd = os.pipe()
+	else:
+		try:
+			master_fd, slave_fd = pty.openpty()
+			got_pty = True
+		except EnvironmentError as e:
+			_disable_openpty = True
+			writemsg("openpty failed: '%s'\n" % str(e),
+				noiselevel=-1)
+			del e
+			master_fd, slave_fd = os.pipe()
+
+	if got_pty:
+		# Disable post-processing of output since otherwise weird
+		# things like \n -> \r\n transformations may occur.
+		mode = termios.tcgetattr(slave_fd)
+		mode[1] &= ~termios.OPOST
+		termios.tcsetattr(slave_fd, termios.TCSANOW, mode)
+
+	if got_pty and \
+		copy_term_size is not None and \
+		os.isatty(copy_term_size):
+		rows, columns = get_term_size()
+		set_term_size(rows, columns, slave_fd)
+
+	return (got_pty, master_fd, slave_fd)