package lumecmd import ( "fmt" "sort" "strings" ) func NewCmdHelp() Command { return Command{ Name: "help", Func: HelpCmd, Use: "", Short: "Show help for a command", } } func HelpCmd(ctx Context) (int, error) { if len(ctx.Args) == 0 { fmt.Print(printHelp(commandRegistry)) } else if len(ctx.Args) >= 1 { if cmdHelp, err := printCmdHelp(ctx.Args[0]); err == nil { fmt.Print(cmdHelp) } else { fmt.Print(err) } } return ExitSuccess, nil } func printHelp(commands map[string]Command) string { var b strings.Builder var maxLen, cmdLen int var keys []string for _, c := range commands { keys = append(keys, c.Name) cmdLen = len(c.Name) if cmdLen > maxLen { maxLen = cmdLen } } fmt.Fprintf(&b, "usage:\n lume []") fmt.Fprintln(&b) fmt.Fprintln(&b, "\ncommands:") sort.Strings(keys) for _, k := range keys { c := commands[k] fmt.Fprintf(&b, " %-*s %s\n", maxLen, c.Name, c.Short) } return b.String() } func printCmdHelp(name string) (string, error) { var b strings.Builder subCmd, ok := commandRegistry[name] if !ok { return "", fmt.Errorf("unknown commnnd: %s\n", name) } if subCmd.Use != "" { fmt.Fprintf(&b, "usage:\n lume %s %s\n", subCmd.Name, subCmd.Use) } else { fmt.Fprintf(&b, "usage:\n lume %s\n", subCmd.Name) } if subCmd.Flags != nil { out := subCmd.Flags.Output() defer subCmd.Flags.SetOutput(out) fmt.Fprintln(&b) fmt.Fprint(&b, "flags:\n") subCmd.Flags.SetOutput(&b) subCmd.Flags.PrintDefaults() } return b.String(), nil }