Add --log option to add a logfile

logging/logging.go

@@ -0,0 +1,73 @@
+package logging
+
+import (
+	"io"
+	"log"
+	"os"
+)
+
+var (
+	defaultWriter    io.Writer
+	additionalWriter io.Writer
+)
+
+type doubleLogger struct {
+	defaultLogger    io.Writer
+	additionalLogger io.Writer
+}
+
+// SetAdditionalOutput defines where we log to. This wraps the writer with another
+// writer to allow a second logging location.
+func SetAdditionalOutput(newAdditionalWriter io.Writer) {
+	additionalWriter = newAdditionalWriter
+	updateLogger()
+}
+
+// SetDefaultOutput defines the default location for logoutput. This can't
+// be overriden by calling SetOutput.
+func SetDefaultOutput(newDefaultWriter io.Writer) {
+	defaultWriter = newDefaultWriter
+	updateLogger()
+
+}
+
+func updateLogger() {
+	if defaultWriter != nil && additionalWriter != nil {
+		log.SetOutput(&doubleLogger{
+			defaultLogger:    defaultWriter,
+			additionalLogger: additionalWriter,
+		})
+	} else if defaultWriter != nil {
+		log.SetOutput(defaultWriter)
+	} else if additionalWriter != nil {
+		log.SetOutput(additionalWriter)
+	} else {
+		log.SetOutput(os.Stdout)
+	}
+}
+
+// Write redirects the output to both the default logger and the additional
+// logger. If any is null, it is skipped. If any errors, an error is returned.
+func (l *doubleLogger) Write(p []byte) (n int, err error) {
+	var (
+		count                int
+		writeErrorDefault    error
+		writeErrorAdditional error
+	)
+	if l.defaultLogger != nil {
+		count, writeErrorDefault = l.defaultLogger.Write(p)
+	}
+	if l.additionalLogger != nil {
+		count, writeErrorAdditional = l.additionalLogger.Write(p)
+	}
+
+	if writeErrorDefault != nil {
+		return 0, writeErrorDefault
+	}
+
+	if writeErrorAdditional != nil {
+		return 0, writeErrorAdditional
+	}
+
+	return count, nil
+}

main.go

@@ -5,9 +5,11 @@ package main
 import (
 	"flag"
 	"fmt"
+	"os"
 
 	"github.com/Bios-Marcel/cordless/app"
 	"github.com/Bios-Marcel/cordless/config"
+	"github.com/Bios-Marcel/cordless/logging"
 	"github.com/Bios-Marcel/cordless/ui/shortcutdialog"
 	"github.com/Bios-Marcel/cordless/version"
 )
@@ -19,8 +21,18 @@ func main() {
 	setScriptDirectory := flag.String("script-dir", "", "Sets the script directory")
 	setConfigFilePath := flag.String("config-file", "", "Sets exact path of the configuration file")
 	accountToUse := flag.String("account", "", "Defines which account cordless tries to load")
+	logPath := flag.String("log", "", "Defines what file we log to")
 	flag.Parse()
 
+	if logPath != nil {
+		logFile, openError := os.OpenFile(*logPath, os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
+		if openError != nil {
+			panic(openError)
+		}
+		defer logFile.Close()
+		logging.SetDefaultOutput(logFile)
+	}
+
 	if setConfigDirectory != nil {
 		config.SetConfigDirectory(*setConfigDirectory)
 	}

ui/window.go

@@ -12,6 +12,7 @@ import (
 	"github.com/mdp/qrterminal/v3"
 
 	"github.com/Bios-Marcel/cordless/fileopen"
+	"github.com/Bios-Marcel/cordless/logging"
 	"github.com/Bios-Marcel/cordless/util/files"
 	"github.com/Bios-Marcel/cordless/util/fuzzy"
 	"github.com/Bios-Marcel/cordless/util/text"
@@ -125,7 +126,7 @@ func NewWindow(doRestart chan bool, app *tview.Application, session *discordgo.S
 	}
 
 	window.commandView = NewCommandView(window.ExecuteCommand)
-	log.SetOutput(window.commandView)
+	logging.SetAdditionalOutput(window.commandView)
 
 	for _, engine := range window.extensionEngines {
 		initError := window.initExtensionEngine(engine)