diff --git a/commandline.go b/commandline.go
index 2566b39..9a51961 100644
--- a/commandline.go
+++ b/commandline.go
@@ -28,6 +28,7 @@ func NewCommandLine(logger *slog.Logger, backend backend.Backend) *CommandLine {
 	return &CommandLine{
 		log:     logger,
 		backend: backend,
+		Listen:  defaultListen,
 	}
 }
 
diff --git a/commandline_test.go b/commandline_test.go
index 28352b3..8e3674a 100644
--- a/commandline_test.go
+++ b/commandline_test.go
@@ -3,12 +3,119 @@ package main
 import (
 	"bytes"
 	"errors"
+	"flag"
 	"github.com/mbretter/go-mmcli-svr/backend"
 	"github.com/stretchr/testify/assert"
 	"log/slog"
+	"os"
 	"testing"
 )
 
+func TestCommandLine_New(t *testing.T) {
+	var buff bytes.Buffer
+	logger := slog.New(slog.NewTextHandler(&buff, nil))
+
+	backendMock := backend.NewBackendMock(t)
+	cmd := NewCommandLine(logger, backendMock)
+
+	assert.Equal(t, defaultListen, cmd.Listen)
+	assert.Equal(t, defaultGpsRefresh, cmd.GpsRefresh)
+	assert.Empty(t, cmd.LocationGatherings)
+	assert.Same(t, logger, cmd.log)
+	assert.Same(t, backendMock, cmd.backend)
+}
+
+func TestCommandLine_Parse(t *testing.T) {
+	tests := []struct {
+		name     string
+		args     []string
+		settings *CommandLine
+		error    string
+	}{
+		{
+			name: "No args",
+			args: []string{},
+			settings: &CommandLine{
+				Listen: defaultListen,
+			},
+		},
+		{
+			name: "Listen",
+			args: []string{"-listen=192.168.1.22:12345"},
+			settings: &CommandLine{
+				Listen: "192.168.1.22:12345",
+			},
+		},
+		{
+			name: "GPS refresh",
+			args: []string{"-gps-refresh=5"},
+			settings: &CommandLine{
+				Listen:     defaultListen,
+				GpsRefresh: 5,
+			},
+		},
+		{
+			name: "Location enable agps-msa",
+			args: []string{"-location-enable=agps-msa"},
+			settings: &CommandLine{
+				Listen:             defaultListen,
+				LocationGatherings: []string{"agps-msa", "gps-nmea"}, // assistet gps needs gps-nmea
+			},
+		},
+		{
+			name: "Location enable gps-nmea",
+			args: []string{"-location-enable=gps-nmea"},
+			settings: &CommandLine{
+				Listen:             defaultListen,
+				LocationGatherings: []string{"gps-nmea"}, // assistet gps needs gps-nmea
+			},
+		},
+		{
+			name: "Location enable agps-msa",
+			args: []string{"-location-enable=agps-msb"},
+			settings: &CommandLine{
+				Listen:             defaultListen,
+				LocationGatherings: []string{"agps-msb", "gps-nmea"}, // assistet gps needs gps-nmea
+			},
+		},
+		{
+			name: "Location enable multi",
+			args: []string{"-location-enable=agps-msa,gps-nmea,gps-raw,3gpp"},
+			settings: &CommandLine{
+				Listen:             defaultListen,
+				LocationGatherings: []string{"3gpp", "agps-msa", "gps-nmea", "gps-raw"},
+			},
+		},
+		{
+			name: "Unknown location",
+			args: []string{"-location-enable=xxx"},
+			settings: &CommandLine{
+				Listen: defaultListen,
+			},
+			error: "unknown location type: xxx",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+
+			os.Args = append([]string{"cmd"}, tt.args...)
+			// reset flag, otherwise redefinition errors might be thrown
+			flag.CommandLine = flag.NewFlagSet(os.Args[0], flag.ExitOnError) //flags are now reset
+
+			cmd := &CommandLine{}
+			err := cmd.Parse()
+
+			assert.Equal(t, tt.settings, cmd)
+			if len(tt.error) > 0 {
+				assert.Equal(t, tt.error, err.Error())
+			} else {
+				assert.Nil(t, err)
+			}
+		})
+	}
+}
+
 func TestCommandLine_Activate(t *testing.T) {
 	tests := []struct {
 		name      string
@@ -18,7 +125,7 @@ func TestCommandLine_Activate(t *testing.T) {
 		settings  *CommandLine
 	}{
 		{
-			name:     "GPS refresh success",
+			name:     "GPS refresh",
 			execArgs: []string{"--location-set-gps-refresh-rate=10"},
 			logs:     []string{`level=INFO msg="Set gps-refresh" refresh=10`},
 			settings: &CommandLine{
@@ -35,7 +142,7 @@ func TestCommandLine_Activate(t *testing.T) {
 			},
 		},
 		{
-			name:     "Location 3gpp enable success",
+			name:     "Location 3gpp enable",
 			execArgs: []string{"--location-enable-3gpp"},
 			logs:     []string{`level=INFO msg="Enable location gatherings" location=3gpp`, `level=INFO msg=mmcli message=success`},
 			settings: &CommandLine{