run.go: add license flag

run.go

@@ -31,8 +31,7 @@ const (
 `
 	slug = `Password Compromise Monitoring Tool
 https://git.dotya.ml/mirre-mt/pcmt
-____________________________________
-	`
+____________________________________`
 
 	licenseHeader = `pcmt - Password Compromise Monitoring Tool
 Copyright (C) git.dotya.ml/wanderer
@@ -54,6 +53,7 @@ var (
 	addr       = flag.String("addr", ":3000", "TCP address:port to listen at")
 	configFlag = flag.String("config", "config.dhall", "Default path of the config file")
 	devel      = flag.Bool("devel", false, "Run the application in dev mode, connect to a local browser-sync instance for hot-reloading")
+	license    = flag.Bool("license", false, "Print licensing information and exit")
 	version    = "dev"
 	log        *slogging.Logger
 
@@ -61,10 +61,15 @@ var (
 )
 
 func run() error {
-	printHeader()
-
 	flag.Parse()
 
+	if *license {
+		fmt.Fprintln(os.Stderr, licenseHeader)
+		os.Exit(0)
+	}
+
+	printHeader()
+
 	err := slogging.Init(true)
 	if err != nil {
 		return ErrCouldNotInitialiseLogger
@@ -164,8 +169,7 @@ func run() error {
 
 func printHeader() {
 	fmt.Fprintf(os.Stderr,
-		"%s\n\n\033[34m%s%s\033[0m\n\n\n",
-		licenseHeader,
+		"\033[34m%s%s\033[0m\n\n\n",
 		banner,
 		slug,
 	)