Improve handling of cmdline errors (#91)

Improve handling of cmdline errors

Author: yannh

cmd/kubeconform/main.go

@@ -48,15 +48,23 @@ func processResults(cancel context.CancelFunc, o output.Output, validationResult
 
 func realMain() int {
 	cfg, out, err := config.FromFlags(os.Args[0], os.Args[1:])
-	if cfg.Help {
-		return 0
-	} else if cfg.Version {
+	if out != "" {
+		o := os.Stderr
+		errCode := 1
+		if cfg.Help {
+			o = os.Stdout
+			errCode = 0
+		}
+		fmt.Fprintln(o, out)
+		return errCode
+	}
+
+	if cfg.Version {
 		fmt.Println(version)
 		return 0
-	} else if out != "" {
-		fmt.Println(out)
-		return 1
-	} else if err != nil {
+	}
+
+	if err != nil {
 		fmt.Fprintf(os.Stderr, "failed parsing command line: %s\n", err.Error())
 		return 1
 	}

pkg/config/config.go

@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"flag"
 	"fmt"
-	"os"
 	"strings"
 )
 
@@ -82,9 +81,7 @@ func FromFlags(progName string, args []string) (Config, string, error) {
 	flags.BoolVar(&c.Help, "h", false, "show help information")
 	flags.BoolVar(&c.Version, "v", false, "show version information")
 	flags.Usage = func() {
-		fmt.Fprintf(os.Stderr, "Usage: %s [OPTION]... [FILE OR FOLDER]...\n", progName)
-
-		flags.SetOutput(os.Stderr)
+		fmt.Fprintf(&buf, "Usage: %s [OPTION]... [FILE OR FOLDER]...\n", progName)
 		flags.PrintDefaults()
 	}