package cli import ( "context" "flag" "fmt" "io" "os" "path/filepath" "sort" "time" ) var ( changeLogURL = "https://github.com/urfave/cli/blob/master/docs/CHANGELOG.md" appActionDeprecationURL = fmt.Sprintf("%s#deprecated-cli-app-action-signature", 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 and help flag HideHelp bool // Boolean to hide built-in help command but keep help flag. // Ignored if HideHelp is true. HideHelpCommand bool // Boolean to hide built-in version flag and the VERSION section of help HideVersion bool // categories contains the categorized commands and is populated on app startup categories CommandCategories // An action to execute when the shell 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 Action ActionFunc // Execute this function if the proper command cannot be found CommandNotFound CommandNotFoundFunc // Execute this function if a 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 // Reader reader to write input to (useful for tests) Reader io.Reader // Writer writer to write output to Writer io.Writer // ErrWriter writes error output ErrWriter io.Writer // ExitErrHandler processes any error encountered while running an App before // it is returned to the caller. If no function is provided, HandleExitCoder // is used as the default behavior. 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 // Boolean to enable short-option handling so user can combine several // single-character bool arguments into one // i.e. foobar -o -v -> foobar -ov UseShortOptionHandling bool 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: "", BashComplete: DefaultAppComplete, Action: helpCommand.Action, Compiled: compileTime(), Reader: os.Stdin, Writer: os.Stdout, ErrWriter: os.Stderr, } } // 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.Name == "" { a.Name = filepath.Base(os.Args[0]) } if a.HelpName == "" { a.HelpName = a.Name } if a.Usage == "" { a.Usage = "A new cli application" } if a.Version == "" { a.HideVersion = true } if a.BashComplete == nil { a.BashComplete = DefaultAppComplete } if a.Action == nil { a.Action = helpCommand.Action } if a.Compiled == (time.Time{}) { a.Compiled = compileTime() } if a.Reader == nil { a.Reader = os.Stdin } if a.Writer == nil { a.Writer = os.Stdout } if a.ErrWriter == nil { a.ErrWriter = os.Stderr } var newCommands []*Command for _, c := range a.Commands { if c.HelpName == "" { c.HelpName = fmt.Sprintf("%s %s", a.HelpName, c.Name) } newCommands = append(newCommands, c) } a.Commands = newCommands if a.Command(helpCommand.Name) == nil && !a.HideHelp { if !a.HideHelpCommand { a.appendCommand(helpCommand) } if HelpFlag != nil { a.appendFlag(HelpFlag) } } if !a.HideVersion { a.appendFlag(VersionFlag) } a.categories = newCommandCategories() for _, command := range a.Commands { a.categories.AddCommand(command.Category, command) } sort.Sort(a.categories.(*commandCategories)) if a.Metadata == nil { a.Metadata = make(map[string]interface{}) } } func (a *App) newFlagSet() (*flag.FlagSet, error) { return flagSet(a.Name, a.Flags) } func (a *App) useShortOptionHandling() bool { return a.UseShortOptionHandling } // 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) { return a.RunContext(context.Background(), arguments) } // RunContext is like Run except it takes a Context that will be // passed to its commands and sub-commands. Through this, you can // propagate timeouts and cancellation requests func (a *App) RunContext(ctx context.Context, 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) set, err := a.newFlagSet() if err != nil { return err } err = parseIter(set, a, arguments[1:], shellComplete) nerr := normalizeFlags(a.Flags, set) context := NewContext(a, set, &Context{Context: ctx}) 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 := context.checkRequiredFlags(a.Flags) 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 { 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 = 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 error // 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) { // Setup also handles HideHelp and HideHelpCommand a.Setup() var 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 set, err := a.newFlagSet() if err != nil { return err } err = parseIter(set, a, ctx.Args().Tail(), ctx.shellComplete) 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 := context.checkRequiredFlags(a.Flags) 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 = 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 } // VisibleCategories returns a slice of categories and commands that are // Hidden=false func (a *App) VisibleCategories() []CommandCategory { ret := []CommandCategory{} for _, category := range a.categories.Categories() { if visible := func() CommandCategory { if len(category.VisibleCommands()) > 0 { 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 { var 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) appendFlag(fl Flag) { if !hasFlag(a.Flags, fl) { a.Flags = append(a.Flags, fl) } } func (a *App) appendCommand(c *Command) { if !hasCommand(a.Commands, c) { a.Commands = append(a.Commands, c) } } 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 }