diff --git a/config.go b/config.go
index 7483bad..9e1e3fd 100644
--- a/config.go
+++ b/config.go
@@ -9,6 +9,14 @@ import (
 	"os/exec"
 	"path/filepath"
 	"runtime"
+
+	homedir "github.com/mitchellh/go-homedir"
+)
+
+const (
+	envCredentials = "GOOGLE_APPLICATION_CREDENTIALS"
+	envClientID    = "IAP_CLIENT_ID"
+	envCurlCommand = "IAP_CURL_BIN"
 )
 
 type Config struct {
@@ -81,7 +89,7 @@ func (cfg *Config) LoadFile(file string) error {
 	return json.NewEncoder(f).Encode(cfg)
 }
 
-func (cfg *Config) GetEnv(url string) (env Env, err error) {
+func (cfg *Config) getEnvFromFile(url string) (env Env, err error) {
 	u1, _ := neturl.Parse(url)
 	for _, service := range cfg.Services {
 		u2, _ := neturl.Parse(service.URL)
@@ -93,6 +101,36 @@ func (cfg *Config) GetEnv(url string) (env Env, err error) {
 	return
 }
 
+func (cfg *Config) GetEnv(url string) (env Env, err error) {
+	env, _ = cfg.getEnvFromFile(url)
+	credentials := os.Getenv(envCredentials)
+	clientID := os.Getenv(envClientID)
+	binary := os.Getenv(envCurlCommand)
+	if credentials == "" {
+		credentials, _ = homedir.Expand(env.Credentials)
+	}
+	if clientID == "" {
+		clientID = env.ClientID
+	}
+	if binary == "" {
+		binary = env.Binary
+	}
+	if credentials == "" {
+		return env, fmt.Errorf("%s is missing", envCredentials)
+	}
+	if clientID == "" {
+		return env, fmt.Errorf("%s is missing", envClientID)
+	}
+	if binary == "" {
+		binary = "curl"
+	}
+	return Env{
+		Credentials: credentials,
+		ClientID:    clientID,
+		Binary:      binary,
+	}, nil
+}
+
 func (cfg *Config) GetURLs() (list []string) {
 	for _, service := range cfg.Services {
 		list = append(list, service.URL)
diff --git a/iap.go b/iap.go
index 286ce62..0c80eab 100644
--- a/iap.go
+++ b/iap.go
@@ -30,10 +30,10 @@ type IAP struct {
 
 func newIAP(sa, id string) (*IAP, error) {
 	if sa == "" {
-		return &IAP{}, errors.New("service account is missing")
+		return &IAP{}, errors.New("Service Account is missing")
 	}
 	if id == "" {
-		return &IAP{}, errors.New("IAP ID is missing")
+		return &IAP{}, errors.New("Client ID is missing")
 	}
 	return &IAP{
 		SA: sa,
@@ -41,6 +41,7 @@ func newIAP(sa, id string) (*IAP, error) {
 	}, nil
 }
 
+// GetToken returns JWT token for authz
 func (c *IAP) GetToken() (token string, err error) {
 	sa, err := ioutil.ReadFile(c.SA)
 	if err != nil {
diff --git a/main.go b/main.go
index cc3ad47..d9e5754 100644
--- a/main.go
+++ b/main.go
@@ -10,14 +10,6 @@ import (
 	"path/filepath"
 	"runtime"
 	"strings"
-
-	homedir "github.com/mitchellh/go-homedir"
-)
-
-const (
-	envCredentials = "GOOGLE_APPLICATION_CREDENTIALS"
-	envClientID    = "IAP_CLIENT_ID"
-	envCurlCommand = "IAP_CURL_BIN"
 )
 
 // CLI represents the attributes for command-line interface
@@ -45,35 +37,35 @@ func main() {
 }
 
 func newCLI(args []string) (CLI, error) {
-	var cli CLI
+	var c CLI
 
 	// TODO: make it customizable
-	cli.stdout = os.Stdout
-	cli.stderr = os.Stderr
+	c.stdout = os.Stdout
+	c.stderr = os.Stderr
 
 	for _, arg := range args {
 		switch arg {
 		case "--list", "--list-urls":
-			cli.opt.list = true
+			c.opt.list = true
 		case "--edit", "--edit-config":
-			cli.opt.edit = true
+			c.opt.edit = true
 		default:
 			u, err := url.Parse(arg)
 			if err == nil {
-				cli.urls = append(cli.urls, *u)
+				c.urls = append(c.urls, *u)
 			} else {
-				cli.args = append(cli.args, arg)
+				c.args = append(c.args, arg)
 			}
 		}
 	}
 
 	dir, _ := configDir()
 	json := filepath.Join(dir, "config.json")
-	if err := cli.cfg.LoadFile(json); err != nil {
-		return cli, err
+	if err := c.cfg.LoadFile(json); err != nil {
+		return c, err
 	}
 
-	return cli, nil
+	return c, nil
 }
 
 func (c CLI) exit(msg interface{}) int {
@@ -84,6 +76,8 @@ func (c CLI) exit(msg interface{}) int {
 	case error:
 		fmt.Fprintf(c.stderr, "Error: %s\n", m.Error())
 		return 1
+	case int:
+		return m
 	case nil:
 		return 0
 	default:
@@ -105,13 +99,12 @@ func (c CLI) run() int {
 		return c.exit(errors.New("invalid url or url not given"))
 	}
 
-	env, _ := c.cfg.GetEnv(url)
-	i, err := getInfo(env)
+	env, err := c.cfg.GetEnv(url)
 	if err != nil {
 		return c.exit(err)
 	}
 
-	iap, err := newIAP(i.credentials, i.clientID)
+	iap, err := newIAP(env.Credentials, env.ClientID)
 	if err != nil {
 		return c.exit(err)
 	}
@@ -127,7 +120,7 @@ func (c CLI) run() int {
 	)
 	args = append(args, url)
 
-	return c.exit(runCommand(i.binary, args))
+	return c.exit(runCommand(env.Binary, args))
 }
 
 func (c CLI) getURL() string {
@@ -137,41 +130,6 @@ func (c CLI) getURL() string {
 	return c.urls[0].String()
 }
 
-type info struct {
-	credentials string
-	clientID    string
-	binary      string
-}
-
-func getInfo(env Env) (info, error) {
-	credentials := os.Getenv(envCredentials)
-	clientID := os.Getenv(envClientID)
-	binary := os.Getenv(envCurlCommand)
-	if credentials == "" {
-		credentials, _ = homedir.Expand(env.Credentials)
-	}
-	if clientID == "" {
-		clientID = env.ClientID
-	}
-	if binary == "" {
-		binary = env.Binary
-	}
-	if credentials == "" {
-		return info{}, fmt.Errorf("%s is missing", envCredentials)
-	}
-	if clientID == "" {
-		return info{}, fmt.Errorf("%s is missing", envClientID)
-	}
-	if binary == "" {
-		binary = "curl"
-	}
-	return info{
-		credentials: credentials,
-		clientID:    clientID,
-		binary:      binary,
-	}, nil
-}
-
 func runCommand(command string, args []string) error {
 	// Check if you have curl command
 	if _, err := exec.LookPath(command); err != nil {