cmdmain

Documentation

Overview

Package cmdmain contains the shared implementation for command-line tools. It is copied from Camlistore, where it is used for camget, camput, camtool, and other Camlistore command-line tools.

Index

• Variables
• func Errorf(format string, args ...interface{})
• func Main()
• func MainDefault(defaultMode string)
• func RegisterCommand(mode string, makeCmd func(Flags *flag.FlagSet) CommandRunner)
• type CommandRunner
• type UsageError
  • func (ue UsageError) Error() string

Variables

var (
	FlagHelp    = flag.Bool("help", false, "print usage")
	FlagVerbose = flag.Bool("verbose", false, "extra debug logging")
)

var (
	// ExtraFlagRegistration allows to add more flags from
	// other packages (with AddFlags) when Main starts.
	ExtraFlagRegistration = func() {}
	// PreExit runs after the subcommand, but before Main terminates
	// with either success or the error from the subcommand.
	PreExit = func() {}
	// ExitWithFailure determines whether the command exits
	// with a non-zero exit status.
	ExitWithFailure bool
	// CheckCwd checks the current working directory, and possibly
	// changes it, or aborts the run if needed.
	CheckCwd = func() {}
)

var (

	// Indirections for replacement by tests
	Stderr io.Writer = os.Stderr
	Stdout io.Writer = os.Stdout
	Stdin  io.Reader = os.Stdin

	Exit = realExit
)

var ErrUsage = UsageError("invalid command")

Functions

func Errorf

func Errorf(format string, args ...interface{})

Errorf prints to Stderr

func Main

func Main()

Main is meant to be the core of a command that has subcommands (modes). Chooses the matching subcommand, and runs it. Call CheckCwd on start, and PreExit before exiting.

func MainDefault

func MainDefault(defaultMode string)

MainDefault is meant to be the core of a command that has subcommands (modes). Chooses the matching subcommand, and runs it. Call CheckCwd on start, and PreExit before exiting.

defaultMode will be used if not arguments given on command line.

func RegisterCommand

func RegisterCommand(mode string, makeCmd func(Flags *flag.FlagSet) CommandRunner)

RegisterCommand adds a mode to the list of modes for the Main command. It is meant to be called in init() for each subcommand.

Types

type CommandRunner

type CommandRunner interface {
	Usage()
	RunCommand(args []string) error
}

CommandRunner is the type that a command mode should implement.

type UsageError

type UsageError string

func (UsageError) Error

func (ue UsageError) Error() string