diff --git a/cli.go b/cli.go
new file mode 100644
index 0000000..0214863
--- /dev/null
+++ b/cli.go
@@ -0,0 +1,188 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"net/http"
+	"os"
+
+	"github.com/schollz/progressbar"
+	"github.com/urfave/cli"
+)
+
+var (
+	errBaseURLRequired  = errors.New("-u, --base-url argument is required")
+	errFileRequired     = errors.New("-f, --file argument is required required")
+	errURLRequired      = errors.New("-u, --url argument is required")
+	errRequestsRequired = errors.New("-n, --requests argument is required")
+
+	baseURL          string
+	filePath         string
+	concurrencyLevel int
+	noOfRequests     int
+	promExport       bool
+	promGwURL        string
+	httpHeader       string
+)
+
+type cassowary struct {
+	fileMode         bool
+	isTLS            bool
+	inputFile        string
+	baseURL          string
+	concurrencyLevel int
+	requests         int
+	promExport       bool
+	promURL          string
+	client           *http.Client
+	bar              *progressbar.ProgressBar
+}
+
+func validateRun(c *cli.Context) error {
+	if baseURL == "" {
+		return errURLRequired
+	}
+	if noOfRequests == 0 {
+		return errRequestsRequired
+	}
+	if concurrencyLevel == 0 {
+		concurrencyLevel = 1
+	}
+	if promGwURL == "" {
+		promExport = false
+	} else {
+		promExport = true
+	}
+
+	cass := &cassowary{
+		fileMode:         false,
+		baseURL:          baseURL,
+		concurrencyLevel: concurrencyLevel,
+		requests:         noOfRequests,
+		promExport:       promExport,
+		promURL:          promGwURL,
+	}
+
+	cass.coordinate()
+
+	return nil
+}
+
+func validateRunFile(c *cli.Context) error {
+	if baseURL == "" {
+		return errBaseURLRequired
+	}
+	if filePath == "" {
+		return errFileRequired
+	}
+	if concurrencyLevel == 0 {
+		concurrencyLevel = 1
+	}
+	if promGwURL == "" {
+		promExport = false
+	} else {
+		promExport = true
+	}
+
+	cass := &cassowary{
+		fileMode:         true,
+		baseURL:          baseURL,
+		concurrencyLevel: concurrencyLevel,
+		requests:         noOfRequests,
+		promExport:       promExport,
+		promURL:          promGwURL,
+	}
+
+	cass.coordinate()
+
+	return nil
+}
+
+func runCLI(args []string) {
+	app := cli.NewApp()
+	app.Name = "cassowary - 鹤鸵"
+	app.HelpName = "cassowary"
+	app.UsageText = "cassowary [command] [command options] [arguments...]"
+	app.EnableBashCompletion = true
+	app.Usage = ""
+	app.Commands = []cli.Command{
+		{
+			Name:  "run-file",
+			Usage: "start load test",
+			Flags: []cli.Flag{
+				cli.StringFlag{
+					Name:        "u, base-url",
+					Usage:       "the base url (absoluteURI) to be used",
+					Destination: &baseURL,
+				},
+				cli.IntFlag{
+					Name:        "c, concurrency",
+					Usage:       "number of concurrent users. defaults to 1",
+					Destination: &concurrencyLevel,
+				},
+				cli.StringFlag{
+					Name:        "f, file",
+					Usage:       "specify `FILE` path, local or www, containing the url suffixes",
+					Destination: &filePath,
+				},
+				cli.StringFlag{
+					Name:        "p, prompushgwurl",
+					Usage:       "specify prometheus push gateway url to send metrics (optional)",
+					Destination: &promGwURL,
+				},
+				cli.StringFlag{
+					Name:        "h, header",
+					Usage:       "Add Arbitrary header line, eg. 'Host: www.example.com'",
+					Destination: &httpHeader,
+				},
+			},
+			Action: validateRunFile,
+		},
+		{
+			Name:  "run",
+			Usage: "start load-test",
+			Flags: []cli.Flag{
+				cli.StringFlag{
+					Name:        "u, url",
+					Usage:       "the url (absoluteURI) to be used",
+					Destination: &baseURL,
+				},
+				cli.IntFlag{
+					Name:        "c, concurrency",
+					Usage:       "number of concurrent users. defaults to 1",
+					Destination: &concurrencyLevel,
+				},
+				cli.IntFlag{
+					Name:        "n, requests",
+					Usage:       "number of requests to perform",
+					Destination: &noOfRequests,
+				},
+				cli.StringFlag{
+					Name:        "p, prompushgwurl",
+					Usage:       "specify prometheus push gateway url to send metrics (optional)",
+					Destination: &promGwURL,
+				},
+				cli.StringFlag{
+					Name:        "h, header",
+					Usage:       "Add Arbitrary header line, eg. 'Host: www.example.com'",
+					Destination: &httpHeader,
+				},
+			},
+			Action: validateRun,
+		},
+	}
+
+	app.CommandNotFound = func(c *cli.Context, command string) {
+		err := cli.ShowAppHelp(c)
+		if err != nil {
+			fmt.Println(err)
+			os.Exit(0)
+		}
+	}
+
+	err := app.Run(os.Args)
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(0)
+	}
+}
diff --git a/main.go b/main.go
index d18aa92..2968f60 100644
--- a/main.go
+++ b/main.go
@@ -1,188 +1,9 @@
 package main
 
 import (
-	"errors"
-	"fmt"
-	"net/http"
 	"os"
-
-	"github.com/schollz/progressbar"
-	"github.com/urfave/cli"
 )
 
-var (
-	errBaseURLRequired  = errors.New("-u, --base-url argument is required")
-	errFileRequired     = errors.New("-f, --file argument is required required")
-	errURLRequired      = errors.New("-u, --url argument is required")
-	errRequestsRequired = errors.New("-n, --requests argument is required")
-
-	baseURL          string
-	filePath         string
-	concurrencyLevel int
-	noOfRequests     int
-	promExport       bool
-	promGwURL        string
-	httpHeader       string
-)
-
-type cassowary struct {
-	fileMode         bool
-	isTLS            bool
-	inputFile        string
-	baseURL          string
-	concurrencyLevel int
-	requests         int
-	promExport       bool
-	promURL          string
-	client           *http.Client
-	bar              *progressbar.ProgressBar
-}
-
-func validateRun(c *cli.Context) error {
-	if baseURL == "" {
-		return errURLRequired
-	}
-	if noOfRequests == 0 {
-		return errRequestsRequired
-	}
-	if concurrencyLevel == 0 {
-		concurrencyLevel = 1
-	}
-	if promGwURL == "" {
-		promExport = false
-	} else {
-		promExport = true
-	}
-
-	cass := &cassowary{
-		fileMode:         false,
-		baseURL:          baseURL,
-		concurrencyLevel: concurrencyLevel,
-		requests:         noOfRequests,
-		promExport:       promExport,
-		promURL:          promGwURL,
-	}
-
-	cass.coordinate()
-
-	return nil
-}
-
-func validateRunFile(c *cli.Context) error {
-	if baseURL == "" {
-		return errBaseURLRequired
-	}
-	if filePath == "" {
-		return errFileRequired
-	}
-	if concurrencyLevel == 0 {
-		concurrencyLevel = 1
-	}
-	if promGwURL == "" {
-		promExport = false
-	} else {
-		promExport = true
-	}
-
-	cass := &cassowary{
-		fileMode:         true,
-		baseURL:          baseURL,
-		concurrencyLevel: concurrencyLevel,
-		requests:         noOfRequests,
-		promExport:       promExport,
-		promURL:          promGwURL,
-	}
-
-	cass.coordinate()
-
-	return nil
-}
-
 func main() {
-	app := cli.NewApp()
-	app.Name = "cassowary - 鹤鸵"
-	app.HelpName = "cassowary"
-	app.UsageText = "cassowary [command] [command options] [arguments...]"
-	app.EnableBashCompletion = true
-	app.Usage = ""
-	app.Commands = []cli.Command{
-		{
-			Name:  "run-file",
-			Usage: "start load test",
-			Flags: []cli.Flag{
-				cli.StringFlag{
-					Name:        "u, base-url",
-					Usage:       "the base url (absoluteURI) to be used",
-					Destination: &baseURL,
-				},
-				cli.IntFlag{
-					Name:        "c, concurrency",
-					Usage:       "number of concurrent users. defaults to 1",
-					Destination: &concurrencyLevel,
-				},
-				cli.StringFlag{
-					Name:        "f, file",
-					Usage:       "specify `FILE` path, local or www, containing the url suffixes",
-					Destination: &filePath,
-				},
-				cli.StringFlag{
-					Name:        "p, prompushgwurl",
-					Usage:       "specify prometheus push gateway url to send metrics (optional)",
-					Destination: &promGwURL,
-				},
-				cli.StringFlag{
-					Name:        "h, header",
-					Usage:       "Add Arbitrary header line, eg. 'Host: www.example.com'",
-					Destination: &httpHeader,
-				},
-			},
-			Action: validateRunFile,
-		},
-		{
-			Name:  "run",
-			Usage: "start load-test",
-			Flags: []cli.Flag{
-				cli.StringFlag{
-					Name:        "u, url",
-					Usage:       "the url (absoluteURI) to be used",
-					Destination: &baseURL,
-				},
-				cli.IntFlag{
-					Name:        "c, concurrency",
-					Usage:       "number of concurrent users. defaults to 1",
-					Destination: &concurrencyLevel,
-				},
-				cli.IntFlag{
-					Name:        "n, requests",
-					Usage:       "number of requests to perform",
-					Destination: &noOfRequests,
-				},
-				cli.StringFlag{
-					Name:        "p, prompushgwurl",
-					Usage:       "specify prometheus push gateway url to send metrics (optional)",
-					Destination: &promGwURL,
-				},
-				cli.StringFlag{
-					Name:        "h, header",
-					Usage:       "Add Arbitrary header line, eg. 'Host: www.example.com'",
-					Destination: &httpHeader,
-				},
-			},
-			Action: validateRun,
-		},
-	}
-
-	app.CommandNotFound = func(c *cli.Context, command string) {
-		err := cli.ShowAppHelp(c)
-		if err != nil {
-			fmt.Println(err)
-			os.Exit(0)
-		}
-	}
-
-	err := app.Run(os.Args)
-	if err != nil {
-		fmt.Println(err)
-		os.Exit(0)
-	}
+	runCLI(os.Args)
 }