import "perkeep/pkg/cmdmain"

Overview

Index

Variables

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

func Logf(format string, v ...interface{})

func Main()

func PrintLicenses()

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

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

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

type CommandRunner

type Demoter

type ExecRunner

type UsageError

    func (ue UsageError) Error() string

Package files

cmdmain.go exec.go

Variables

var (
    FlagVersion = flag.Bool("version", false, "show version")
    FlagHelp    = flag.Bool("help", false, "print usage")
    FlagVerbose = flag.Bool("verbose", false, "extra debug logging")
    FlagLegal   = flag.Bool("legal", false, "show licenses")
)

var (
    // ExtraFlagRegistration allows to add more flags from
    // other packages (with AddFlags) when Main starts.
    ExtraFlagRegistration = func() {}
    // PostFlag runs code that needs to happen after flags were parsed, but
    // before the subcommand is run.
    PostFlag = 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
)

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")

func Errorf

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

Errorf prints to Stderr, regardless of FlagVerbose.

func Logf

func Logf(format string, v ...interface{})

Logf logs to Stderr if FlagVerbose, and is silent otherwise.

func Main

func Main()

Main is meant to be the core of a command that has subcommands (modes), such as pk-put or pk.

func PrintLicenses

func PrintLicenses()

PrintLicenses prints all the licences registered by go4.org/legal for this program.

func Printf

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

Printf prints to Stderr if FlagVerbose, and is silent otherwise.

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, and also specifies that this mode is just another executable that runs as a new cmdmain command. The executable to run is determined by the LookPath implementation for this mode.

func RegisterMode

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

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

type CommandRunner

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

CommandRunner is the type that a command mode should implement.

type Demoter

type Demoter interface {
    CommandRunner
    Demote() bool
}

Demoter is an interface that boring commands can implement to demote themselves in the tool listing, for boring or low-level subcommands. They only show up in --help mode.

type ExecRunner

type ExecRunner interface {
    CommandRunner
    LookPath() (string, error)
}

ExecRunner is the type that a command mode should implement when that mode just calls a new executable that will run as a new command.

type UsageError

type UsageError string

func (UsageError) Error

func (ue UsageError) Error() string