package cli
import (
"fmt"
"io"
"io/ioutil"
"os"
"path/filepath"
"sort"
"time"
)
var (
changeLogURL = "https://github.com/urfave/cli/blob/master/CHANGELOG.md"
appActionDeprecationURL = fmt.Sprintf("%s#deprecated-cli-app-action-signature", changeLogURL)
runAndExitOnErrorDeprecationURL = fmt.Sprintf("%s#deprecated-cli-app-runandexitonerror", changeLogURL)
contactSysadmin = "This is an error in the application. Please contact the distributor of this application if this is not you."
errInvalidActionType = NewExitError("ERROR invalid Action type. "+
fmt.Sprintf("Must be `func(*Context`)` or `func(*Context) error). %s", contactSysadmin)+
fmt.Sprintf("See %s", appActionDeprecationURL), 2)
)
// App is the main structure of a cli application. It is recommended that
// an app be created with the cli.NewApp() function
type App struct {
// The name of the program. Defaults to path.Base(os.Args[0])
Name string
// Full name of command for help, defaults to Name
HelpName string
// Description of the program.
Usage string
// Text to override the USAGE section of help
UsageText string
// Description of the program argument format.
ArgsUsage string
// Version of the program
Version string
// Description of the program
Description string
// List of commands to execute
Commands []Command
// List of flags to parse
Flags []Flag
// Boolean to enable bash completion commands
EnableBashCompletion bool
// Boolean to hide built-in help command
HideHelp bool
// Boolean to hide built-in version flag and the VERSION section of help
HideVersion bool
// Populate on app startup, only gettable through method Categories()
categories CommandCategories
// An action to execute when the bash-completion flag is set
BashComplete BashCompleteFunc
// An action to execute before any subcommands are run, but after the context is ready
// If a non-nil error is returned, no subcommands are run
Before BeforeFunc
// An action to execute after any subcommands are run, but after the subcommand has finished
// It is run even if Action() panics
After AfterFunc
// The action to execute when no subcommands are specified
// Expects a `cli.ActionFunc` but will accept the *deprecated* signature of `func(*cli.Context) {}`
// *Note*: support for the deprecated `Action` signature will be removed in a future version
Action interface{}
// Execute this function if the proper command cannot be found
CommandNotFound CommandNotFoundFunc
// Execute this function if an usage error occurs
OnUsageError OnUsageErrorFunc
// Compilation date
Compiled time.Time
// List of all authors who contributed
Authors []Author
// Copyright of the binary if any
Copyright string
// Name of Author (Note: Use App.Authors, this is deprecated)
Author string
// Email of Author (Note: Use App.Authors, this is deprecated)
Email string
// Writer writer to write output to
Writer io.Writer
// ErrWriter writes error output
ErrWriter io.Writer
// Other custom info
Metadata map[string]interface{}
// Carries a function which returns app specific info.
ExtraInfo func() map[string]string
// CustomAppHelpTemplate the text template for app help topic.
// cli.go uses text/template to render templates. You can
// render custom help text by setting this variable.
CustomAppHelpTemplate string
didSetup bool
}
// Tries to find out when this binary was compiled.
// Returns the current time if it fails to find it.
func compileTime() time.Time {
info, err := os.Stat(os.Args[0])
if err != nil {
return time.Now()
}
return info.ModTime()
}
// NewApp creates a new cli Application with some reasonable defaults for Name,
// Usage, Version and Action.
func NewApp() *App {
return &App{
Name: filepath.Base(os.Args[0]),
HelpName: filepath.Base(os.Args[0]),
Usage: "A new cli application",
UsageText: "",
Version: "0.0.0",
BashComplete: DefaultAppComplete,
Action: helpCommand.Action,
Compiled: compileTime(),
Writer: os.Stdout,
}
}
// Setup runs initialization code to ensure all data structures are ready for
// `Run` or inspection prior to `Run`. It is internally called by `Run`, but
// will return early if setup has already happened.
func (a *App) Setup() {
if a.didSetup {
return
}
a.didSetup = true
if a.Author != "" || a.Email != "" {
a.Authors = append(a.Authors, Author{Name: a.Author, Email: a.Email})
}
newCmds := []Command{}
for _, c := range a.Commands {
if c.HelpName == "" {
c.HelpName = fmt.Sprintf("%s %s", a.HelpName, c.Name)
}
newCmds = append(newCmds, c)
}
a.Commands = newCmds
if a.Command(helpCommand.Name) == nil && !a.HideHelp {
a.Commands = append(a.Commands, helpCommand)
if (HelpFlag != BoolFlag{}) {
a.appendFlag(HelpFlag)
}
}
if !a.HideVersion {
a.appendFlag(VersionFlag)
}
a.categories = CommandCategories{}
for _, command := range a.Commands {
a.categories = a.categories.AddCommand(command.Category, command)
}
sort.Sort(a.categories)
if a.Metadata == nil {
a.Metadata = make(map[string]interface{})
}
if a.Writer == nil {
a.Writer = os.Stdout
}
}
// Run is the entry point to the cli app. Parses the arguments slice and routes
// to the proper flag/args combination
func (a *App) Run(arguments []string) (err error) {
a.Setup()
// handle the completion flag separately from the flagset since
// completion could be attempted after a flag, but before its value was put
// on the command line. this causes the flagset to interpret the completion
// flag name as the value of the flag before it which is undesirable
// note that we can only do this because the shell autocomplete function
// always appends the completion flag at the end of the command
shellComplete, arguments := checkShellCompleteFlag(a, arguments)
// parse flags
set, err := flagSet(a.Name, a.Flags)
if err != nil {
return err
}
set.SetOutput(ioutil.Discard)
err = set.Parse(arguments[1:])
nerr := normalizeFlags(a.Flags, set)
context := NewContext(a, set, nil)
if nerr != nil {
fmt.Fprintln(a.Writer, nerr)
ShowAppHelp(context)
return nerr
}
context.shellComplete = shellComplete
if checkCompletions(context) {
return nil
}
if err != nil {
if a.OnUsageError != nil {
err := a.OnUsageError(context, err, false)
HandleExitCoder(err)
return err
}
fmt.Fprintf(a.Writer, "%s %s\n\n", "Incorrect Usage.", err.Error())
ShowAppHelp(context)
return err
}
if !a.HideHelp && checkHelp(context) {
ShowAppHelp(context)
return nil
}
if !a.HideVersion && checkVersion(context) {
ShowVersion(context)
return nil
}
if a.After != nil {
defer func() {
if afterErr := a.After(context); afterErr != nil {
if err != nil {
err = NewMultiError(err, afterErr)
} else {
err = afterErr
}
}
}()
}
if a.Before != nil {
beforeErr := a.Before(context)
if beforeErr != nil {
ShowAppHelp(context)
HandleExitCoder(beforeErr)
err = beforeErr
return err
}
}
args := context.Args()
if args.Present() {
name := args.First()
c := a.Command(name)
if c != nil {
return c.Run(context)
}
}
if a.Action == nil {
a.Action = helpCommand.Action
}
// Run default Action
err = HandleAction(a.Action, context)
HandleExitCoder(err)
return err
}
// RunAndExitOnError calls .Run() and exits non-zero if an error was returned
//
// Deprecated: instead you should return an error that fulfills cli.ExitCoder
// to cli.App.Run. This will cause the application to exit with the given eror
// code in the cli.ExitCoder
func (a *App) RunAndExitOnError() {
if err := a.Run(os.Args); err != nil {
fmt.Fprintln(a.errWriter(), err)
OsExiter(1)
}
}
// RunAsSubcommand invokes the subcommand given the context, parses ctx.Args() to
// generate command-specific flags
func (a *App) RunAsSubcommand(ctx *Context) (err error) {
// append help to commands
if len(a.Commands) > 0 {
if a.Command(helpCommand.Name) == nil && !a.HideHelp {
a.Commands = append(a.Commands, helpCommand)
if (HelpFlag != BoolFlag{}) {
a.appendFlag(HelpFlag)
}
}
}
newCmds := []Command{}
for _, c := range a.Commands {
if c.HelpName == "" {
c.HelpName = fmt.Sprintf("%s %s", a.HelpName, c.Name)
}
newCmds = append(newCmds, c)
}
a.Commands = newCmds
// parse flags
set, err := flagSet(a.Name, a.Flags)
if err != nil {
return err
}
set.SetOutput(ioutil.Discard)
err = set.Parse(ctx.Args().Tail())
nerr := normalizeFlags(a.Flags, set)
context := NewContext(a, set, ctx)
if nerr != nil {
fmt.Fprintln(a.Writer, nerr)
fmt.Fprintln(a.Writer)
if len(a.Commands) > 0 {
ShowSubcommandHelp(context)
} else {
ShowCommandHelp(ctx, context.Args().First())
}
return nerr
}
if checkCompletions(context) {
return nil
}
if err != nil {
if a.OnUsageError != nil {
err = a.OnUsageError(context, err, true)
HandleExitCoder(err)
return err
}
fmt.Fprintf(a.Writer, "%s %s\n\n", "Incorrect Usage.", err.Error())
ShowSubcommandHelp(context)
return err
}
if len(a.Commands) > 0 {
if checkSubcommandHelp(context) {
return nil
}
} else {
if checkCommandHelp(ctx, context.Args().First()) {
return nil
}
}
if a.After != nil {
defer func() {
afterErr := a.After(context)
if afterErr != nil {
HandleExitCoder(err)
if err != nil {
err = NewMultiError(err, afterErr)
} else {
err = afterErr
}
}
}()
}
if a.Before != nil {
beforeErr := a.Before(context)
if beforeErr != nil {
HandleExitCoder(beforeErr)
err = beforeErr
return err
}
}
args := context.Args()
if args.Present() {
name := args.First()
c := a.Command(name)
if c != nil {
return c.Run(context)
}
}
// Run default Action
err = HandleAction(a.Action, context)
HandleExitCoder(err)
return err
}
// Command returns the named command on App. Returns nil if the command does not exist
func (a *App) Command(name string) *Command {
for _, c := range a.Commands {
if c.HasName(name) {
return &c
}
}
return nil
}
// Categories returns a slice containing all the categories with the commands they contain
func (a *App) Categories() CommandCategories {
return a.categories
}
// VisibleCategories returns a slice of categories and commands that are
// Hidden=false
func (a *App) VisibleCategories() []*CommandCategory {
ret := []*CommandCategory{}
for _, category := range a.categories {
if visible := func() *CommandCategory {
for _, command := range category.Commands {
if !command.Hidden {
return category
}
}
return nil
}(); visible != nil {
ret = append(ret, visible)
}
}
return ret
}
// VisibleCommands returns a slice of the Commands with Hidden=false
func (a *App) VisibleCommands() []Command {
ret := []Command{}
for _, command := range a.Commands {
if !command.Hidden {
ret = append(ret, command)
}
}
return ret
}
// VisibleFlags returns a slice of the Flags with Hidden=false
func (a *App) VisibleFlags() []Flag {
return visibleFlags(a.Flags)
}
func (a *App) hasFlag(flag Flag) bool {
for _, f := range a.Flags {
if flag == f {
return true
}
}
return false
}
func (a *App) errWriter() io.Writer {
// When the app ErrWriter is nil use the package level one.
if a.ErrWriter == nil {
return ErrWriter
}
return a.ErrWriter
}
func (a *App) appendFlag(flag Flag) {
if !a.hasFlag(flag) {
a.Flags = append(a.Flags, flag)
}
}
// Author represents someone who has contributed to a cli project.
type Author struct {
Name string // The Authors name
Email string // The Authors email
}
// String makes Author comply to the Stringer interface, to allow an easy print in the templating process
func (a Author) String() string {
e := ""
if a.Email != "" {
e = " <" + a.Email + ">"
}
return fmt.Sprintf("%v%v", a.Name, e)
}
// HandleAction attempts to figure out which Action signature was used. If
// it's an ActionFunc or a func with the legacy signature for Action, the func
// is run!
func HandleAction(action interface{}, context *Context) (err error) {
if a, ok := action.(ActionFunc); ok {
return a(context)
} else if a, ok := action.(func(*Context) error); ok {
return a(context)
} else if a, ok := action.(func(*Context)); ok { // deprecated function signature
a(context)
return nil
} else {
return errInvalidActionType
}
}
