improved command line argument handling, migrated json to config at higher debug levels

config/parser.go

@@ -195,11 +195,11 @@ func (p *Parser) setState(state int) {
 		p.lastcheck = nil
 	}
 
-	if p.DebugLevel > 0 {
+	if p.DebugLevel > 1 {
 		fmt.Printf("Parser state: %s", p.stateName())
 	}
 	p.states = append(p.states, state)
-	if p.DebugLevel > 0 {
+	if p.DebugLevel > 1 {
 		fmt.Printf(" -> %s\n", p.stateName())
 	}
 }

main.go

@@ -1,18 +1,19 @@
 package main
 
 import (
+	"alrm/config"
 	"encoding/json"
-	"fmt"
 	"flag"
+	"fmt"
 	"os"
 	"strings"
-	"alrm/config"
 )
 
 func main() {
 	cfgPath := flag.String("c", "", "path to configuration file")
 	debuglvl := flag.Int("d", 0, "debug level")
 
+	flag.Usage = printUsage
 	flag.Parse()
 
 	if *cfgPath == "" {
@@ -23,63 +24,72 @@ func main() {
 			*cfgPath = "/etc/alrmrc"
 		}
 		if *cfgPath == "" {
-			fmt.Fprintf(os.Stderr, "Cannot find configuration\n")
+			fmt.Fprintf(os.Stderr, "cannot find configuration\n")
 			os.Exit(1)
 		}
 	}
 
 	command := strings.ToLower(flag.Arg(0))
 	switch command {
-		case "json":
-			cfg, err := config.ReadConfig(*cfgPath, *debuglvl)
-			if err != nil {
-				fmt.Fprintf(os.Stderr, "%s\n", err.Error())
-				os.Exit(1)
-			}
+	case "config":
+		cfg, err := config.ReadConfig(*cfgPath, *debuglvl)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "%s\n", err.Error())
+			os.Exit(1)
+		}
 
+		if *debuglvl > 0 {
 			o, err := json.MarshalIndent(cfg, "", "  ")
 			if err != nil {
 				fmt.Fprintf(os.Stderr, "JSON error: %s\n", err.Error())
 				os.Exit(1)
 			}
-			fmt.Fprintf(os.Stdout, "%s\n", string(o))
+			fmt.Printf("%s\n", string(o))
+		}
 
-		case "config", "":
-			_, err := config.ReadConfig(*cfgPath, *debuglvl)
-			if err != nil {
-				fmt.Fprintf(os.Stderr, "%s\n", err.Error())
-				os.Exit(1)
-			}
-			fmt.Fprintf(os.Stdout, "Config is OK.\n")
+		fmt.Printf("config is OK\n")
 
-		case "check":
-			tn := flag.Arg(1)
-			if tn == "" {
-				fmt.Fprintf(os.Stderr, "test requires a host or group\n")
-				os.Exit(1)
-			}
-
-			cfg, err := config.ReadConfig(*cfgPath, 0)
-			if err != nil {
-				fmt.Fprintf(os.Stderr, "%s\n", err.Error())
-				os.Exit(1)
-			}
+	case "check":
+		tn := flag.Arg(1)
+		if tn == "" {
+			fmt.Fprintf(os.Stderr, "check requires a host or group\n")
+			os.Exit(1)
+		}
 
-			group, exists := cfg.Groups[tn]
-			if !exists {
-				fmt.Fprintf(os.Stderr, "group or host is not defined\n")
-				os.Exit(1)
-			}
+		cfg, err := config.ReadConfig(*cfgPath, 0)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "%s\n", err.Error())
+			os.Exit(1)
+		}
 
-			err = group.Check(*debuglvl)
-			if err != nil {
-				fmt.Fprintf(os.Stderr, "Check failed: %s\n", err.Error())
-				os.Exit(1)
-			}
-			fmt.Fprintf(os.Stdout, "Check successful\n")
+		group, exists := cfg.Groups[tn]
+		if !exists {
+			fmt.Fprintf(os.Stderr, "group or host is not defined\n")
+			os.Exit(1)
+		}
 
-		default:
-			fmt.Fprintf(os.Stderr, "Unknown command: %s\n", command)
+		err = group.Check(*debuglvl)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "check failed: %s\n", err.Error())
 			os.Exit(1)
+		}
+		fmt.Printf("check successful\n")
+
+	case "":
+		printUsage()
+
+	default:
+		fmt.Fprintf(os.Stderr, "unknown command: %s\n", command)
+		os.Exit(1)
 	}
 }
+
+func printUsage() {
+	fmt.Printf("Usage: %s [args] <action> ...\n", os.Args[0])
+	fmt.Printf("Arguments:\n")
+	fmt.Printf("  -c <path>  : path to configuration file\n")
+	fmt.Printf("  -d <level> : debug level (0-9, higher for more debugging)\n")
+	fmt.Printf("Actions:\n")
+	fmt.Printf("  verify configuration:     %s [args] config\n", os.Args[0])
+	fmt.Printf("  run a check manually:     %s [args] check <host/group>\n", os.Args[0])
+}