make sure the xrandr we call to get information properly quits, and detect failure...

diff --git a/external_screen.py b/external_screen.py
index e365ef58b51e082b3c3edd2af8047b6a39ee4bdd..a419908a2a95ffe8f50c55cf0645ac78b23fed2a 100755 (executable)
--- a/external_screen.py
+++ b/external_screen.py
@@ -10,17 +10,19 @@ def getXrandrInformation():
        connector = None # current connector
        for line in p.stdout:
                # new connector?
-               m = re.search('^([\w]+) connected ', line)
+               m = re.search(r'^([\w]+) connected ', line)
                if m is not None:
                        connector = m.groups()[0]
                        assert connector not in connectors
                        connectors[connector] = []
                        continue
                # new resolution?
-               m = re.search('^   ([\d]+)x([\d]+) +', line)
+               m = re.search(r'^   ([\d]+)x([\d]+) +', line)
                if m is not None:
                        assert connector is not None
                        connectors[connector].append((int(m.groups()[0]), int(m.groups()[1])))
+       p.communicate()
+       if p.returncode != 0: raise Exception("Querying xrandr for data failed")
        return connectors
 
 def res2str(res):
@@ -50,6 +52,6 @@ if externalResolutions is not None: # we need to ask what to do
        else:
                externalArgs += ["--right-of", internalName]
 # and do it
-args = ["--output", internalName] + internalArgs + ["--output", externalName] + externalArgs
-print args
-subprocess.check_call(["xrandr"] + args)
+call = ["xrandr", "--output", internalName] + internalArgs + ["--output", externalName] + externalArgs
+print "Call that will be made:",call
+subprocess.check_call(call)