package cli import ( "fmt" "io" "io/ioutil" "os" "path/filepath" "reflect" "sort" "strings" "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." errNonFuncAction = NewExitError("ERROR invalid Action type. "+ fmt.Sprintf("Must be a func of type `cli.ActionFunc`. %s", contactSysadmin)+ fmt.Sprintf("See %s", appActionDeprecationURL), 2) errInvalidActionSignature = NewExitError("ERROR invalid Action signature. "+ fmt.Sprintf("Must be `cli.ActionFunc`. %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 // 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{} 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.EnableBashCompletion { a.appendFlag(BashCompletionFlag) } 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{}) } } // 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() // parse flags set := flagSet(a.Name, a.Flags) 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 } 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\n\n", "Incorrect Usage.") 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 { fmt.Fprintf(a.Writer, "%v\n\n", beforeErr) 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) } } // 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 // append flags if a.EnableBashCompletion { a.appendFlag(BashCompletionFlag) } // parse flags set := flagSet(a.Name, a.Flags) 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\n\n", "Incorrect Usage.") 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 uses ✧✧✧reflection✧✧✧ to figure out if the given Action is an // ActionFunc, a func with the legacy signature for Action, or some other // invalid thing. 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) { defer func() { if r := recover(); r != nil { // Try to detect a known reflection error from *this scope*, rather than // swallowing all panics that may happen when calling an Action func. s := fmt.Sprintf("%v", r) if strings.HasPrefix(s, "reflect: ") && strings.Contains(s, "too many input arguments") { err = NewExitError(fmt.Sprintf("ERROR unknown Action error: %v.", r), 2) } else { panic(r) } } }() if reflect.TypeOf(action).Kind() != reflect.Func { return errNonFuncAction } vals := reflect.ValueOf(action).Call([]reflect.Value{reflect.ValueOf(context)}) if len(vals) == 0 { return nil } if len(vals) > 1 { return errInvalidActionSignature } if retErr, ok := vals[0].Interface().(error); vals[0].IsValid() && ok { return retErr } return err }