Stderr support

Author: neumond

computercraft/back.lua

@@ -69,11 +69,9 @@ while true do
             event_sub[msg.event] = nil
         elseif msg.action == 'close' then
             if msg.error ~= nil then
-                print(msg.error)
+                io.stderr:write(msg.error)
             end
             break
-        else
-            print(msg)
         end
     elseif event_sub[event] == true then
         ws.send(textutils.serializeJSON{

computercraft/sess.py

@@ -54,8 +54,9 @@ def get_current_session():
 
 
 class StdFileProxy:
-    def __init__(self, native):
+    def __init__(self, native, err):
         self._native = native
+        self._err = err
 
     def read(self, size=-1):
         if _is_global_greenlet():
@@ -80,9 +81,14 @@ def write(self, s):
         if _is_global_greenlet():
             return self._native.write(s)
         else:
-            return rproc.nil(eval_lua(
-                lua_call('io.write', s)
-            ))
+            if self._err:
+                return rproc.nil(eval_lua(
+                    lua_call('io.stderr:write', s)
+                ))
+            else:
+                return rproc.nil(eval_lua(
+                    lua_call('io.write', s)
+                ))
 
     def fileno(self):
         if _is_global_greenlet():
@@ -129,9 +135,9 @@ def install_import_hook():
 
 
 install_import_hook()
-sys.stdin = StdFileProxy(sys.__stdin__)
-sys.stdout = StdFileProxy(sys.__stdout__)
-sys.stderr = StdFileProxy(sys.__stderr__)
+sys.stdin = StdFileProxy(sys.__stdin__, False)
+sys.stdout = StdFileProxy(sys.__stdout__, False)
+sys.stderr = StdFileProxy(sys.__stderr__, True)
 
 
 def eval_lua(lua_code, immediate=False):

examples/broken.py

@@ -0,0 +1 @@
+raise ValueError