require one user at least

cmd/root.go

@@ -101,7 +101,11 @@ var RootCmd = &cobra.Command{
 			}
 			sshUsers = append(sshUsers, sshUser{name: splits[0], password: splits[1]})
 		}
-
+		if len(sshUsers) == 0 {
+			return fmt.Errorf(`No user specified
+e.g. --user "john:mypassword"
+e.g. --user "john:"`)
+		}
 		// (base: https://gist.github.com/jpillora/b480fde82bff51a06238)
 		sshConfig := &ssh.ServerConfig{
 			//Define a function to run when a client attempts a password login

main/main.go

@@ -1,14 +1,12 @@
 package main
 
 import (
-	"fmt"
 	"github.com/nwtgck/handy-sshd/cmd"
 	"os"
 )
 
 func main() {
 	if err := cmd.RootCmd.Execute(); err != nil {
-		_, _ = fmt.Fprintf(os.Stderr, err.Error())
 		os.Exit(-1)
 	}
 }