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 // Execute this function to handle ExitErrors. If not provided, HandleExitCoder is provided to // function as a default, so this is optional. ExitErrHandler ExitErrHandlerFunc // 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) a.handleExitCoder(context, 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 } cerr := checkRequiredFlags(a.Flags, context) if cerr != nil { ShowAppHelp(context) return cerr } 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) a.handleExitCoder(context, 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) a.handleExitCoder(context, 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) a.handleExitCoder(context, 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 } } cerr := checkRequiredFlags(a.Flags, context) if cerr != nil { ShowSubcommandHelp(context) return cerr } if a.After != nil { defer func() { afterErr := a.After(context) if afterErr != nil { a.handleExitCoder(context, err) if err != nil { err = NewMultiError(err, afterErr) } else { err = afterErr } } }() } if a.Before != nil { beforeErr := a.Before(context) if beforeErr != nil { a.handleExitCoder(context, 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) a.handleExitCoder(context, 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) } } func (a *App) handleExitCoder(context *Context, err error) { if a.ExitErrHandler != nil { a.ExitErrHandler(context, err) } else { HandleExitCoder(err) } } // 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) { switch a := action.(type) { case ActionFunc: return a(context) case func(*Context) error: return a(context) case func(*Context): // deprecated function signature a(context) return nil } return errInvalidActionType }