diff -r 51bf56ba3c10 -r 0bbb006204fc printrun-src/printrun/power/osx.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/printrun-src/printrun/power/osx.py	Fri Jun 03 09:16:07 2016 +0200
@@ -0,0 +1,82 @@
+# This file is part of the Printrun suite.
+#
+# Printrun 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.
+#
+# Printrun 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 Printrun.  If not, see <http://www.gnu.org/licenses/>.
+#
+# Imported from http://www.benden.us/journal/2014/OS-X-Power-Management-No-Sleep-Howto/
+# Copyright (c) Joseph Benden 2014
+
+import ctypes
+import CoreFoundation
+import objc
+
+def SetUpIOFramework():
+    # load the IOKit library
+    framework = ctypes.cdll.LoadLibrary(
+        '/System/Library/Frameworks/IOKit.framework/IOKit')
+
+    # declare parameters as described in IOPMLib.h
+    framework.IOPMAssertionCreateWithName.argtypes = [
+        ctypes.c_void_p,  # CFStringRef
+        ctypes.c_uint32,  # IOPMAssertionLevel
+        ctypes.c_void_p,  # CFStringRef
+        ctypes.POINTER(ctypes.c_uint32)]  # IOPMAssertionID
+    framework.IOPMAssertionRelease.argtypes = [
+        ctypes.c_uint32]  # IOPMAssertionID
+    return framework
+
+def StringToCFString(string):
+    # we'll need to convert our strings before use
+    try:
+        encoding = CoreFoundation.kCFStringEncodingASCII
+    except AttributeError:
+        encoding = 0x600
+    cfstring = CoreFoundation.CFStringCreateWithCString(None, string, encoding)
+    return objc.pyobjc_id(cfstring.nsstring())
+
+def AssertionCreateWithName(framework, a_type,
+                            a_level, a_reason):
+    # this method will create an assertion using the IOKit library
+    # several parameters
+    a_id = ctypes.c_uint32(0)
+    a_type = StringToCFString(a_type)
+    a_reason = StringToCFString(a_reason)
+    a_error = framework.IOPMAssertionCreateWithName(
+        a_type, a_level, a_reason, ctypes.byref(a_id))
+
+    # we get back a 0 or stderr, along with a unique c_uint
+    # representing the assertion ID so we can release it later
+    return a_error, a_id
+
+def AssertionRelease(framework, assertion_id):
+    # releasing the assertion is easy, and also returns a 0 on
+    # success, or stderr otherwise
+    return framework.IOPMAssertionRelease(assertion_id)
+
+def inhibit_sleep_osx(reason):
+    no_idle = "NoIdleSleepAssertion"
+
+    # Initialize IOKit framework
+    if inhibit_sleep_osx.framework is None:
+        inhibit_sleep_osx.framework = SetUpIOFramework()
+    framework = inhibit_sleep_osx.framework
+
+    # Start inhibition
+    ret, a_id = AssertionCreateWithName(framework, no_idle, 255, reason)
+    inhibit_sleep_osx.assertion_id = a_id
+    return ret
+inhibit_sleep_osx.framework = None
+
+def deinhibit_sleep_osx():
+    return AssertionRelease(inhibit_sleep_osx.framework,
+                            inhibit_sleep_osx.assertion_id)