prog

Documentation

Overview

Package prog provides the entry point to Elvish. Its subpackages correspond to subprograms of Elvish.

Index

• Variables
• func BadUsage(msg string) error
• func Exit(exit int) error
• func Run(fds [3]*os.File, args []string, p Program) int
• type Flags
• type Program
  • func Composite(programs ...Program) Program

Variables

var DeprecationLevel = 17

DeprecationLevel is a global flag that controls which deprecations to show. If its value is X, Elvish shows deprecations that should be shown for version 0.X.

var ErrNotSuitable = errors.New("internal error: no suitable subprogram")

ErrNotSuitable is a special error that may be returned by Program.Run, to signify that this Program should not be run. It is useful when a Program is used in Composite.

Functions

func BadUsage

func BadUsage(msg string) error

BadUsage returns a special error that may be returned by Program.Run. It causes the main function to print out a message, the usage information and exit with 2.

func Exit

func Exit(exit int) error

Exit returns a special error that may be returned by Program.Run. It causes the main function to exit with the given code without printing any error messages. Exit(0) returns nil.

func Run

func Run(fds [3]*os.File, args []string, p Program) int

Run parses command-line flags and runs the first applicable subprogram. It returns the exit status of the program.

Types

type Flags

type Flags struct {
	Log, CPUProfile string

	Help, Version, BuildInfo, JSON bool

	CodeInArg, CompileOnly, NoRc bool
	RC                           string

	Port int

	Daemon bool
	Forked int

	DB, Sock string
}

Flags keeps command-line flags.

type Program

type Program interface {
	// Run runs the subprogram.
	Run(fds [3]*os.File, f *Flags, args []string) error
}

Program represents a subprogram.

func Composite

func Composite(programs ...Program) Program

Composite returns a Program that tries each of the given programs, terminating at the first one that doesn't return NotSuitable().