logfile output other than stdout

Author: richard-li-sp

README.md

@@ -422,7 +422,7 @@ the message.
 	"source": "source_identifier",
 	"to": "originator_identifier",
 	"command": {
-		"id": "identifier (use the identifier from the request",
+		"id": "identifier (use the identifier from the request)",
 		"action": "info",
 		"type": "user",
 		"map": {"field1": "data1", "field2": "data2"}
@@ -441,7 +441,7 @@ the message.
 		"id": "identifier",
 		"action": "room_request",
 		"type": "name / id",
-		"data": "room
+		"data": "room"
 	}
 }
 ```
@@ -456,11 +456,17 @@ the message.
 		"id": "identifier",
 		"action": "info",
 		"type": "room",
+		"error": "Error message (if request fails)",
 		"map": {"field1": "data1", "field2": "data2"}
 	}
 }
 ```
 
+**Note** "error" field is only send back when error occurs. Information
+requester should first evaluate whether "error" field is empty before
+proceeding. If "error" field contains value, the map part of the information
+response should be considered invalided and discarded.
+
 **Note** Both user and room information request are neither validated nor
 evaluated by Priscilla server, it's simply forwarded to the target adapter. The
 information response from the adapter, is also directly forwarded to the

commandQuery.go

@@ -15,6 +15,7 @@ type commandBlock struct {
 	Type    string            `json:"type"`
 	Time    int64             `json:"time,omitempty"`
 	Data    string            `json:"data,omitempty"`
+	Error   string            `json"error,omitempty"`
 	Array   []string          `json:"array,omitempty"`
 	Options []string          `json:"options,omitempty"`
 	Map     map[string]string `json:"map,omitempty"`

priscilla.go

@@ -79,16 +79,49 @@ var unhandledAResponders *list.List
 var subRegex *regexp.Regexp
 var help *list.List
 
+var version, build string
+
 func main() {
 	confFile := flag.String("conf", "", "Conf files, you know, conf files")
 	loglevel :=
 		flag.String("loglevel", "warn", "log level: debug/info/warn/error")
+	logfile := flag.String("log", "STDOUT", "Log file")
+	showversion := flag.Bool("version", false, "show version and exit")
 
 	flag.Parse()
 
+	if *showversion {
+		if version == "" {
+			fmt.Println("Version: development")
+		} else {
+			fmt.Println("Version:", version)
+		}
+
+		if build == "" {
+			fmt.Println("Build: development")
+		} else {
+			fmt.Println("Build:", build)
+		}
+		os.Exit(0)
+	}
+
 	var err error
 
-	logger, err = prislog.NewLogger(os.Stdout, *loglevel)
+	var logwriter *os.File
+
+	if *logfile == "STDOUT" {
+		logwriter = os.Stdout
+	} else {
+		logwriter, err = os.OpenFile(*logfile,
+			os.O_RDWR|os.O_CREATE|os.O_APPEND, 0644)
+		if err != nil {
+			fmt.Println("Unable to write to log file", *logfile, ":", err)
+			os.Exit(1)
+		}
+		defer logwriter.Close()
+	}
+
+	logger, err = prislog.NewLogger(logwriter, *loglevel)
 
 	if err != nil {
 		fmt.Println("Error initializing logger: ", err)
@@ -222,13 +255,15 @@ func main() {
 	}
 
 	if conf.Port == 0 {
-		logger.Error.Fatal("No port specified!")
+		logger.Warn.Println("No port specified, using default: 4517")
+		conf.Port = 4517
 	}
 
 	// Prefix need to be free of excess spaces
 	conf.Prefix = strings.Trim(conf.Prefix, " ")
 	if len(conf.Prefix) < 1 {
-		logger.Error.Fatal("Prefix is empty")
+		logger.Warn.Println("No prefix specified, using default: pris")
+		conf.Prefix = "pris"
 	}
 	conf.Prefix += " "
 	conf.prefixLen = len(conf.Prefix)