Added exit code support

Now the exit code can be returned by BeforeFn, ActionFn and AfterFn.

The `os.Exit` function is not called by this packaged

This closes #66 and closes #164

app.go

@@ -8,6 +8,11 @@ import (
 	"time"
 )
 
+var (
+	// Set to 125 which is the highest number not used in most shells
+	DefaultExitCode int = 0
+)
+
 // App is the main structure of a cli application. It is recomended that
 // an app be created with the cli.NewApp() function
 type App struct {
@@ -77,7 +82,7 @@ func NewApp() *App {
 }
 
 // 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) {
+func (a *App) Run(arguments []string) (ec int, err error) {
 	if a.Author != "" || a.Email != "" {
 		a.Authors = append(a.Authors, Author{Name: a.Author, Email: a.Email})
 	}
@@ -108,7 +113,7 @@ func (a *App) Run(arguments []string) (err error) {
 		fmt.Fprintln(a.Writer, nerr)
 		context := NewContext(a, set, nil)
 		ShowAppHelp(context)
-		return nerr
+		return DefaultExitCode, nerr
 	}
 	context := NewContext(a, set, nil)
 
@@ -116,24 +121,24 @@ func (a *App) Run(arguments []string) (err error) {
 		fmt.Fprintln(a.Writer, "Incorrect Usage.")
 		fmt.Fprintln(a.Writer)
 		ShowAppHelp(context)
-		return err
+		return DefaultExitCode, err
 	}
 
 	if checkCompletions(context) {
-		return nil
+		return 0, nil
 	}
 
 	if checkHelp(context) {
-		return nil
+		return 0, nil
 	}
 
 	if checkVersion(context) {
-		return nil
+		return 0, nil
 	}
 
 	if a.After != nil {
 		defer func() {
-			afterErr := a.After(context)
+			afterEc, afterErr := a.After(context)
 			if afterErr != nil {
 				if err != nil {
 					err = NewMultiError(err, afterErr)
@@ -141,13 +146,14 @@ func (a *App) Run(arguments []string) (err error) {
 					err = afterErr
 				}
 			}
+			ec = afterEc
 		}()
 	}
 
 	if a.Before != nil {
-		err := a.Before(context)
+		ec, err = a.Before(context)
 		if err != nil {
-			return err
+			return ec, err
 		}
 	}
 
@@ -161,20 +167,19 @@ func (a *App) Run(arguments []string) (err error) {
 	}
 
 	// Run default Action
-	a.Action(context)
-	return nil
+	return a.Action(context), nil
 }
 
 // Another entry point to the cli app, takes care of passing arguments and error handling
 func (a *App) RunAndExitOnError() {
-	if err := a.Run(os.Args); err != nil {
+	if exitCode, err := a.Run(os.Args); err != nil {
 		fmt.Fprintln(os.Stderr, err)
-		os.Exit(1)
+		os.Exit(exitCode)
 	}
 }
 
 // Invokes the subcommand given the context, parses ctx.Args() to generate command-specific flags
-func (a *App) RunAsSubcommand(ctx *Context) (err error) {
+func (a *App) RunAsSubcommand(ctx *Context) (ec int, err error) {
 	// append help to commands
 	if len(a.Commands) > 0 {
 		if a.Command(helpCommand.Name) == nil && !a.HideHelp {
@@ -205,33 +210,33 @@ func (a *App) RunAsSubcommand(ctx *Context) (err error) {
 		} else {
 			ShowCommandHelp(ctx, context.Args().First())
 		}
-		return nerr
+		return DefaultExitCode, nerr
 	}
 
 	if err != nil {
 		fmt.Fprintln(a.Writer, "Incorrect Usage.")
 		fmt.Fprintln(a.Writer)
 		ShowSubcommandHelp(context)
-		return err
+		return DefaultExitCode, err
 	}
 
 	if checkCompletions(context) {
-		return nil
+		return 0, nil
 	}
 
 	if len(a.Commands) > 0 {
 		if checkSubcommandHelp(context) {
-			return nil
+			return 0, nil
 		}
 	} else {
 		if checkCommandHelp(ctx, context.Args().First()) {
-			return nil
+			return 0, nil
 		}
 	}
 
 	if a.After != nil {
 		defer func() {
-			afterErr := a.After(context)
+			afterEc, afterErr := a.After(context)
 			if afterErr != nil {
 				if err != nil {
 					err = NewMultiError(err, afterErr)
@@ -239,13 +244,14 @@ func (a *App) RunAsSubcommand(ctx *Context) (err error) {
 					err = afterErr
 				}
 			}
+			ec = afterEc
 		}()
 	}
 
 	if a.Before != nil {
-		err := a.Before(context)
+		ec, err = a.Before(context)
 		if err != nil {
-			return err
+			return ec, err
 		}
 	}
 
@@ -259,9 +265,7 @@ func (a *App) RunAsSubcommand(ctx *Context) (err error) {
 	}
 
 	// Run default Action
-	a.Action(context)
-
-	return nil
+	return a.Action(context), nil
 }
 
 // Returns the named command on App. Returns nil if the command does not exist

command.go

@@ -50,7 +50,7 @@ func (c Command) FullName() string {
 }
 
 // Invokes the command given the context, parses ctx.Args() to generate command-specific flags
-func (c Command) Run(ctx *Context) error {
+func (c Command) Run(ctx *Context) (int, error) {
 	if len(c.Subcommands) > 0 || c.Before != nil || c.After != nil {
 		return c.startApp(ctx)
 	}
@@ -104,7 +104,7 @@ func (c Command) Run(ctx *Context) error {
 		fmt.Fprintln(ctx.App.Writer, "Incorrect Usage.")
 		fmt.Fprintln(ctx.App.Writer)
 		ShowCommandHelp(ctx, c.Name)
-		return err
+		return DefaultExitCode, err
 	}
 
 	nerr := normalizeFlags(c.Flags, set)
@@ -112,20 +112,19 @@ func (c Command) Run(ctx *Context) error {
 		fmt.Fprintln(ctx.App.Writer, nerr)
 		fmt.Fprintln(ctx.App.Writer)
 		ShowCommandHelp(ctx, c.Name)
-		return nerr
+		return DefaultExitCode, nerr
 	}
 	context := NewContext(ctx.App, set, ctx)
 
 	if checkCommandCompletions(context, c.Name) {
-		return nil
+		return 0, nil
 	}
 
 	if checkCommandHelp(context, c.Name) {
-		return nil
+		return 0, nil
 	}
 	context.Command = c
-	c.Action(context)
-	return nil
+	return c.Action(context), nil
 }
 
 func (c Command) Names() []string {
@@ -148,7 +147,7 @@ func (c Command) HasName(name string) bool {
 	return false
 }
 
-func (c Command) startApp(ctx *Context) error {
+func (c Command) startApp(ctx *Context) (int, error) {
 	app := NewApp()
 
 	// set the name and usage

funcs.go

@@ -5,14 +5,14 @@ type BashCompleteFn func(*Context)
 
 // 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
-type BeforeFn func(*Context) error
+type BeforeFn func(*Context) (int, error)
 
 // An action to execute after any subcommands are run, but after the subcommand has finished
 // It is run even if Action() panics
-type AfterFn func(*Context) error
+type AfterFn func(*Context) (int, error)
 
 // The action to execute when no subcommands are specified
-type ActionFn func(*Context)
+type ActionFn func(*Context) int
 
 // Execute this function if the proper command cannot be found
 type CommandNotFoundFn func(*Context, string)

help.go

@@ -72,13 +72,14 @@ var helpCommand = Command{
 	Name:    "help",
 	Aliases: []string{"h"},
 	Usage:   "Shows a list of commands or help for one command",
-	Action: func(c *Context) {
+	Action: func(c *Context) int {
 		args := c.Args()
 		if args.Present() {
 			ShowCommandHelp(c, args.First())
 		} else {
 			ShowAppHelp(c)
 		}
+		return 0
 	},
 }
 
@@ -86,13 +87,14 @@ var helpSubcommand = Command{
 	Name:    "help",
 	Aliases: []string{"h"},
 	Usage:   "Shows a list of commands or help for one command",
-	Action: func(c *Context) {
+	Action: func(c *Context) int {
 		args := c.Args()
 		if args.Present() {
 			ShowCommandHelp(c, args.First())
 		} else {
 			ShowSubcommandHelp(c)
 		}
+		return 0
 	},
 }