added protected peripheral manager and file system logger

scada-common/log.lua

@@ -0,0 +1,43 @@
+--
+-- File System Logger
+--
+
+-- we use extra short abbreviations since computer craft screens are very small
+-- underscores are used since some of these names are used elsewhere (e.g. 'debug' is a lua table)
+
+local file_handle = fs.open("/log.txt", "a")
+
+local _log = function (msg)
+    local stamped = os.date("[%c] ") .. msg
+    file_handle.writeLine(stamped)
+    file_handle.flush()
+end
+
+function _debug(msg, trace)
+    local dbg_info = ""
+    
+    if trace then
+        local name = ""
+
+        if debug.getinfo(2).name ~= nil then
+            name = ":" .. debug.getinfo(2).name .. "():"
+        end
+        
+        dbg_info = debug.getinfo(2).short_src .. ":" .. name .. 
+            debug.getinfo(2).currentline .. " > "
+    end
+
+    _log("[DBG] " .. dbg_info .. msg)
+end
+
+function _warning(msg)
+    _log("[WRN] " .. msg)
+end
+
+function _error(msg)
+    _log("[ERR] " .. msg)
+end
+
+function _fatal(msg)
+    _log("[FTL] " .. msg)
+end