@@ -83,8 +83,14 @@ func (cli *DockerCli) Cmd(args ...string) error {

 	return cli.CmdHelp()

 }

-func (cli *DockerCli) Subcmd(name, signature, description string) *flag.FlagSet {

-	flags := flag.NewFlagSet(name, flag.ContinueOnError)

+func (cli *DockerCli) Subcmd(name, signature, description string, exitOnError bool) *flag.FlagSet {

+	var errorHandling flag.ErrorHandling

+	if exitOnError {

+		errorHandling = flag.ExitOnError

+	} else {

+		errorHandling = flag.ContinueOnError

+	}

+	flags := flag.NewFlagSet(name, errorHandling)

 	flags.Usage = func() {

 		options := ""

 		if flags.FlagCountUndeprecated() > 0 {

@@ -77,7 +77,7 @@ func (cli *DockerCli) CmdHelp(args ...string) error {

 }

 func (cli *DockerCli) CmdBuild(args ...string) error {

-	cmd := cli.Subcmd("build", "PATH | URL | -", "Build a new image from the source code at PATH")

+	cmd := cli.Subcmd("build", "PATH | URL | -", "Build a new image from the source code at PATH", true)

 	tag := cmd.String([]string{"t", "-tag"}, "", "Repository name (and optionally a tag) to be applied to the resulting image in case of success")

 	suppressOutput := cmd.Bool([]string{"q", "-quiet"}, false, "Suppress the verbose output generated by the containers")

 	noCache := cmd.Bool([]string{"#no-cache", "-no-cache"}, false, "Do not use cache when building the image")

@@ -86,9 +86,7 @@ func (cli *DockerCli) CmdBuild(args ...string) error {

 	pull := cmd.Bool([]string{"-pull"}, false, "Always attempt to pull a newer version of the image")

 	cmd.Require(flag.Exact, 1)

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, true)

 	var (

 		context  archive.Archive

@@ -246,7 +244,7 @@ func (cli *DockerCli) CmdBuild(args ...string) error {

 // 'docker login': login / register a user to registry service.

 func (cli *DockerCli) CmdLogin(args ...string) error {

-	cmd := cli.Subcmd("login", "[SERVER]", "Register or log in to a Docker registry server, if no server is specified \""+registry.IndexServerAddress()+"\" is the default.")

+	cmd := cli.Subcmd("login", "[SERVER]", "Register or log in to a Docker registry server, if no server is specified \""+registry.IndexServerAddress()+"\" is the default.", true)

 	cmd.Require(flag.Max, 1)

 	var username, password, email string

@@ -255,9 +253,7 @@ func (cli *DockerCli) CmdLogin(args ...string) error {

 	cmd.StringVar(&password, []string{"p", "-password"}, "", "Password")

 	cmd.StringVar(&email, []string{"e", "-email"}, "", "Email")

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, true)

 	serverAddress := registry.IndexServerAddress()

 	if len(cmd.Args()) > 0 {

@@ -364,12 +360,10 @@ func (cli *DockerCli) CmdLogin(args ...string) error {

 // log out from a Docker registry

 func (cli *DockerCli) CmdLogout(args ...string) error {

-	cmd := cli.Subcmd("logout", "[SERVER]", "Log out from a Docker registry, if no server is specified \""+registry.IndexServerAddress()+"\" is the default.")

+	cmd := cli.Subcmd("logout", "[SERVER]", "Log out from a Docker registry, if no server is specified \""+registry.IndexServerAddress()+"\" is the default.", true)

 	cmd.Require(flag.Max, 1)

-	if err := utils.ParseFlags(cmd, args, false); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, false)

 	serverAddress := registry.IndexServerAddress()

 	if len(cmd.Args()) > 0 {

 		serverAddress = cmd.Arg(0)

@@ -391,12 +385,10 @@ func (cli *DockerCli) CmdLogout(args ...string) error {

 // 'docker wait': block until a container stops

 func (cli *DockerCli) CmdWait(args ...string) error {

-	cmd := cli.Subcmd("wait", "CONTAINER [CONTAINER...]", "Block until a container stops, then print its exit code.")

+	cmd := cli.Subcmd("wait", "CONTAINER [CONTAINER...]", "Block until a container stops, then print its exit code.", true)

 	cmd.Require(flag.Min, 1)

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, true)

 	var encounteredError error

 	for _, name := range cmd.Args() {

@@ -413,12 +405,10 @@ func (cli *DockerCli) CmdWait(args ...string) error {

 // 'docker version': show version information

 func (cli *DockerCli) CmdVersion(args ...string) error {

-	cmd := cli.Subcmd("version", "", "Show the Docker version information.")

+	cmd := cli.Subcmd("version", "", "Show the Docker version information.", true)

 	cmd.Require(flag.Exact, 0)

-	if err := utils.ParseFlags(cmd, args, false); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, false)

 	if dockerversion.VERSION != "" {

 		fmt.Fprintf(cli.out, "Client version: %s\n", dockerversion.VERSION)

@@ -457,11 +447,9 @@ func (cli *DockerCli) CmdVersion(args ...string) error {

 // 'docker info': display system-wide information.

 func (cli *DockerCli) CmdInfo(args ...string) error {

-	cmd := cli.Subcmd("info", "", "Display system-wide information")

+	cmd := cli.Subcmd("info", "", "Display system-wide information", true)

 	cmd.Require(flag.Exact, 0)

-	if err := utils.ParseFlags(cmd, args, false); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, false)

 	body, _, err := readBody(cli.call("GET", "/info", nil, false))

 	if err != nil {

@@ -573,13 +561,11 @@ func (cli *DockerCli) CmdInfo(args ...string) error {

 }

 func (cli *DockerCli) CmdStop(args ...string) error {

-	cmd := cli.Subcmd("stop", "CONTAINER [CONTAINER...]", "Stop a running container by sending SIGTERM and then SIGKILL after a grace period")

+	cmd := cli.Subcmd("stop", "CONTAINER [CONTAINER...]", "Stop a running container by sending SIGTERM and then SIGKILL after a grace period", true)

 	nSeconds := cmd.Int([]string{"t", "-time"}, 10, "Number of seconds to wait for the container to stop before killing it. Default is 10 seconds.")

 	cmd.Require(flag.Min, 1)

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, true)

 	v := url.Values{}

 	v.Set("t", strconv.Itoa(*nSeconds))

@@ -598,13 +584,11 @@ func (cli *DockerCli) CmdStop(args ...string) error {

 }

 func (cli *DockerCli) CmdRestart(args ...string) error {

-	cmd := cli.Subcmd("restart", "CONTAINER [CONTAINER...]", "Restart a running container")

+	cmd := cli.Subcmd("restart", "CONTAINER [CONTAINER...]", "Restart a running container", true)

 	nSeconds := cmd.Int([]string{"t", "-time"}, 10, "Number of seconds to try to stop for before killing the container. Once killed it will then be restarted. Default is 10 seconds.")

 	cmd.Require(flag.Min, 1)

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, true)

 	v := url.Values{}

 	v.Set("t", strconv.Itoa(*nSeconds))

@@ -653,15 +637,13 @@ func (cli *DockerCli) CmdStart(args ...string) error {

 		cErr chan error

 		tty  bool

-		cmd       = cli.Subcmd("start", "CONTAINER [CONTAINER...]", "Restart a stopped container")

+		cmd       = cli.Subcmd("start", "CONTAINER [CONTAINER...]", "Restart a stopped container", true)

 		attach    = cmd.Bool([]string{"a", "-attach"}, false, "Attach container's STDOUT and STDERR and forward all signals to the process")

 		openStdin = cmd.Bool([]string{"i", "-interactive"}, false, "Attach container's STDIN")

 	)

 	cmd.Require(flag.Min, 1)

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, true)

 	hijacked := make(chan io.Closer)

@@ -763,11 +745,9 @@ func (cli *DockerCli) CmdStart(args ...string) error {

 }

 func (cli *DockerCli) CmdUnpause(args ...string) error {

-	cmd := cli.Subcmd("unpause", "CONTAINER", "Unpause all processes within a container")

+	cmd := cli.Subcmd("unpause", "CONTAINER", "Unpause all processes within a container", true)

 	cmd.Require(flag.Exact, 1)

-	if err := utils.ParseFlags(cmd, args, false); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, false)

 	var encounteredError error

 	for _, name := range cmd.Args() {

@@ -782,11 +762,9 @@ func (cli *DockerCli) CmdUnpause(args ...string) error {

 }

 func (cli *DockerCli) CmdPause(args ...string) error {

-	cmd := cli.Subcmd("pause", "CONTAINER", "Pause all processes within a container")

+	cmd := cli.Subcmd("pause", "CONTAINER", "Pause all processes within a container", true)

 	cmd.Require(flag.Exact, 1)

-	if err := utils.ParseFlags(cmd, args, false); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, false)

 	var encounteredError error

 	for _, name := range cmd.Args() {

@@ -801,13 +779,11 @@ func (cli *DockerCli) CmdPause(args ...string) error {

 }

 func (cli *DockerCli) CmdInspect(args ...string) error {

-	cmd := cli.Subcmd("inspect", "CONTAINER|IMAGE [CONTAINER|IMAGE...]", "Return low-level information on a container or image")

+	cmd := cli.Subcmd("inspect", "CONTAINER|IMAGE [CONTAINER|IMAGE...]", "Return low-level information on a container or image", true)

 	tmplStr := cmd.String([]string{"f", "#format", "-format"}, "", "Format the output using the given go template.")

 	cmd.Require(flag.Min, 1)

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, true)

 	var tmpl *template.Template

 	if *tmplStr != "" {

@@ -879,12 +855,10 @@ func (cli *DockerCli) CmdInspect(args ...string) error {

 }

 func (cli *DockerCli) CmdTop(args ...string) error {

-	cmd := cli.Subcmd("top", "CONTAINER [ps OPTIONS]", "Display the running processes of a container")

+	cmd := cli.Subcmd("top", "CONTAINER [ps OPTIONS]", "Display the running processes of a container", true)

 	cmd.Require(flag.Min, 1)

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, true)

 	val := url.Values{}

 	if cmd.NArg() > 1 {

@@ -913,11 +887,9 @@ func (cli *DockerCli) CmdTop(args ...string) error {

 }

 func (cli *DockerCli) CmdPort(args ...string) error {

-	cmd := cli.Subcmd("port", "CONTAINER [PRIVATE_PORT[/PROTO]]", "List port mappings for the CONTAINER, or lookup the public-facing port that is NAT-ed to the PRIVATE_PORT")

+	cmd := cli.Subcmd("port", "CONTAINER [PRIVATE_PORT[/PROTO]]", "List port mappings for the CONTAINER, or lookup the public-facing port that is NAT-ed to the PRIVATE_PORT", true)

 	cmd.Require(flag.Min, 1)

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, true)

 	stream, _, err := cli.call("GET", "/containers/"+cmd.Arg(0)+"/json", nil, false)

 	if err != nil {

@@ -966,15 +938,13 @@ func (cli *DockerCli) CmdPort(args ...string) error {

 // 'docker rmi IMAGE' removes all images with the name IMAGE

 func (cli *DockerCli) CmdRmi(args ...string) error {

 	var (

-		cmd     = cli.Subcmd("rmi", "IMAGE [IMAGE...]", "Remove one or more images")

+		cmd     = cli.Subcmd("rmi", "IMAGE [IMAGE...]", "Remove one or more images", true)

 		force   = cmd.Bool([]string{"f", "-force"}, false, "Force removal of the image")

 		noprune = cmd.Bool([]string{"-no-prune"}, false, "Do not delete untagged parents")

 	)

 	cmd.Require(flag.Min, 1)

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, true)

 	v := url.Values{}

 	if *force {

@@ -1010,14 +980,12 @@ func (cli *DockerCli) CmdRmi(args ...string) error {

 }

 func (cli *DockerCli) CmdHistory(args ...string) error {

-	cmd := cli.Subcmd("history", "IMAGE", "Show the history of an image")

+	cmd := cli.Subcmd("history", "IMAGE", "Show the history of an image", true)

 	quiet := cmd.Bool([]string{"q", "-quiet"}, false, "Only show numeric IDs")

 	noTrunc := cmd.Bool([]string{"#notrunc", "-no-trunc"}, false, "Don't truncate output")

 	cmd.Require(flag.Exact, 1)

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, true)

 	body, _, err := readBody(cli.call("GET", "/images/"+cmd.Arg(0)+"/history", nil, false))

 	if err != nil {

@@ -1064,15 +1032,13 @@ func (cli *DockerCli) CmdHistory(args ...string) error {

 }

 func (cli *DockerCli) CmdRm(args ...string) error {

-	cmd := cli.Subcmd("rm", "CONTAINER [CONTAINER...]", "Remove one or more containers")

+	cmd := cli.Subcmd("rm", "CONTAINER [CONTAINER...]", "Remove one or more containers", true)

 	v := cmd.Bool([]string{"v", "-volumes"}, false, "Remove the volumes associated with the container")

 	link := cmd.Bool([]string{"l", "#link", "-link"}, false, "Remove the specified link and not the underlying container")

 	force := cmd.Bool([]string{"f", "-force"}, false, "Force the removal of a running container (uses SIGKILL)")

 	cmd.Require(flag.Min, 1)

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, true)

 	val := url.Values{}

 	if *v {

@@ -1101,13 +1067,11 @@ func (cli *DockerCli) CmdRm(args ...string) error {

 // 'docker kill NAME' kills a running container

 func (cli *DockerCli) CmdKill(args ...string) error {

-	cmd := cli.Subcmd("kill", "CONTAINER [CONTAINER...]", "Kill a running container using SIGKILL or a specified signal")

+	cmd := cli.Subcmd("kill", "CONTAINER [CONTAINER...]", "Kill a running container using SIGKILL or a specified signal", true)

 	signal := cmd.String([]string{"s", "-signal"}, "KILL", "Signal to send to the container")

 	cmd.Require(flag.Min, 1)

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, true)

 	var encounteredError error

 	for _, name := range cmd.Args() {

@@ -1122,12 +1086,10 @@ func (cli *DockerCli) CmdKill(args ...string) error {

 }

 func (cli *DockerCli) CmdImport(args ...string) error {

-	cmd := cli.Subcmd("import", "URL|- [REPOSITORY[:TAG]]", "Create an empty filesystem image and import the contents of the tarball (.tar, .tar.gz, .tgz, .bzip, .tar.xz, .txz) into it, then optionally tag it.")

+	cmd := cli.Subcmd("import", "URL|- [REPOSITORY[:TAG]]", "Create an empty filesystem image and import the contents of the tarball (.tar, .tar.gz, .tgz, .bzip, .tar.xz, .txz) into it, then optionally tag it.", true)

 	cmd.Require(flag.Min, 1)

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, true)

 	var (

 		v          = url.Values{}

@@ -1161,12 +1123,10 @@ func (cli *DockerCli) CmdImport(args ...string) error {

 }

 func (cli *DockerCli) CmdPush(args ...string) error {

-	cmd := cli.Subcmd("push", "NAME[:TAG]", "Push an image or a repository to the registry")

+	cmd := cli.Subcmd("push", "NAME[:TAG]", "Push an image or a repository to the registry", true)

 	cmd.Require(flag.Exact, 1)

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, true)

 	name := cmd.Arg(0)

@@ -1224,13 +1184,11 @@ func (cli *DockerCli) CmdPush(args ...string) error {

 }

 func (cli *DockerCli) CmdPull(args ...string) error {

-	cmd := cli.Subcmd("pull", "NAME[:TAG]", "Pull an image or a repository from the registry")

+	cmd := cli.Subcmd("pull", "NAME[:TAG]", "Pull an image or a repository from the registry", true)

 	allTags := cmd.Bool([]string{"a", "-all-tags"}, false, "Download all tagged images in the repository")

 	cmd.Require(flag.Exact, 1)

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, true)

 	var (

 		v         = url.Values{}

@@ -1288,7 +1246,7 @@ func (cli *DockerCli) CmdPull(args ...string) error {

 }

 func (cli *DockerCli) CmdImages(args ...string) error {

-	cmd := cli.Subcmd("images", "[REPOSITORY]", "List images")

+	cmd := cli.Subcmd("images", "[REPOSITORY]", "List images", true)

 	quiet := cmd.Bool([]string{"q", "-quiet"}, false, "Only show numeric IDs")

 	all := cmd.Bool([]string{"a", "-all"}, false, "Show all images (by default filter out the intermediate image layers)")

 	noTrunc := cmd.Bool([]string{"#notrunc", "-no-trunc"}, false, "Don't truncate output")

@@ -1300,9 +1258,7 @@ func (cli *DockerCli) CmdImages(args ...string) error {

 	cmd.Var(&flFilter, []string{"f", "-filter"}, "Provide filter values (i.e. 'dangling=true')")

 	cmd.Require(flag.Max, 1)

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, true)

 	// Consolidate all filter flags, and sanity check them early.

 	// They'll get process in the daemon/server.

@@ -1528,7 +1484,7 @@ func (cli *DockerCli) CmdPs(args ...string) error {

 		psFilterArgs = filters.Args{}

 		v            = url.Values{}

-		cmd      = cli.Subcmd("ps", "", "List containers")

+		cmd      = cli.Subcmd("ps", "", "List containers", true)

 		quiet    = cmd.Bool([]string{"q", "-quiet"}, false, "Only display numeric IDs")

 		size     = cmd.Bool([]string{"s", "-size"}, false, "Display total file sizes")

 		all      = cmd.Bool([]string{"a", "-all"}, false, "Show all containers. Only running containers are shown by default.")

@@ -1543,9 +1499,7 @@ func (cli *DockerCli) CmdPs(args ...string) error {

 	cmd.Var(&flFilter, []string{"f", "-filter"}, "Provide filter values. Valid filters:\nexited=<int> - containers with exit code of <int>\nstatus=(restarting|running|paused|exited)")

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, true)

 	if *last == -1 && *nLatest {

 		*last = 1

 	}

@@ -1680,7 +1634,7 @@ func (cli *DockerCli) CmdPs(args ...string) error {

 }

 func (cli *DockerCli) CmdCommit(args ...string) error {

-	cmd := cli.Subcmd("commit", "CONTAINER [REPOSITORY[:TAG]]", "Create a new image from a container's changes")

+	cmd := cli.Subcmd("commit", "CONTAINER [REPOSITORY[:TAG]]", "Create a new image from a container's changes", true)

 	flPause := cmd.Bool([]string{"p", "-pause"}, true, "Pause container during commit")

 	flComment := cmd.String([]string{"m", "-message"}, "", "Commit message")

 	flAuthor := cmd.String([]string{"a", "#author", "-author"}, "", "Author (e.g., \"John Hannibal Smith <hannibal@a-team.com>\")")

@@ -1688,9 +1642,7 @@ func (cli *DockerCli) CmdCommit(args ...string) error {

 	flConfig := cmd.String([]string{"#run", "#-run"}, "", "This option is deprecated and will be removed in a future version in favor of inline Dockerfile-compatible commands")

 	cmd.Require(flag.Max, 2)

 	cmd.Require(flag.Min, 1)

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, true)

 	var (

 		name            = cmd.Arg(0)

@@ -1738,16 +1690,14 @@ func (cli *DockerCli) CmdCommit(args ...string) error {

 }

 func (cli *DockerCli) CmdEvents(args ...string) error {

-	cmd := cli.Subcmd("events", "", "Get real time events from the server")

+	cmd := cli.Subcmd("events", "", "Get real time events from the server", true)

 	since := cmd.String([]string{"#since", "-since"}, "", "Show all events created since timestamp")

 	until := cmd.String([]string{"-until"}, "", "Stream events until this timestamp")

 	flFilter := opts.NewListOpts(nil)

 	cmd.Var(&flFilter, []string{"f", "-filter"}, "Provide filter values (i.e. 'event=stop')")

 	cmd.Require(flag.Exact, 0)

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, true)

 	var (

 		v               = url.Values{}

@@ -1795,12 +1745,10 @@ func (cli *DockerCli) CmdEvents(args ...string) error {

 }

 func (cli *DockerCli) CmdExport(args ...string) error {

-	cmd := cli.Subcmd("export", "CONTAINER", "Export the contents of a filesystem as a tar archive to STDOUT")

+	cmd := cli.Subcmd("export", "CONTAINER", "Export the contents of a filesystem as a tar archive to STDOUT", true)

 	cmd.Require(flag.Exact, 1)

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, true)

 	if err := cli.stream("GET", "/containers/"+cmd.Arg(0)+"/export", nil, cli.out, nil); err != nil {

 		return err

@@ -1809,12 +1757,10 @@ func (cli *DockerCli) CmdExport(args ...string) error {

 }

 func (cli *DockerCli) CmdDiff(args ...string) error {

-	cmd := cli.Subcmd("diff", "CONTAINER", "Inspect changes on a container's filesystem")

+	cmd := cli.Subcmd("diff", "CONTAINER", "Inspect changes on a container's filesystem", true)

 	cmd.Require(flag.Exact, 1)

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, true)

 	body, _, err := readBody(cli.call("GET", "/containers/"+cmd.Arg(0)+"/changes", nil, false))

@@ -1843,16 +1789,14 @@ func (cli *DockerCli) CmdDiff(args ...string) error {

 func (cli *DockerCli) CmdLogs(args ...string) error {

 	var (

-		cmd    = cli.Subcmd("logs", "CONTAINER", "Fetch the logs of a container")

+		cmd    = cli.Subcmd("logs", "CONTAINER", "Fetch the logs of a container", true)

 		follow = cmd.Bool([]string{"f", "-follow"}, false, "Follow log output")

 		times  = cmd.Bool([]string{"t", "-timestamps"}, false, "Show timestamps")

 		tail   = cmd.String([]string{"-tail"}, "all", "Output the specified number of lines at the end of logs (defaults to all logs)")

 	)

 	cmd.Require(flag.Exact, 1)

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, true)

 	name := cmd.Arg(0)

@@ -1884,15 +1828,13 @@ func (cli *DockerCli) CmdLogs(args ...string) error {

 func (cli *DockerCli) CmdAttach(args ...string) error {

 	var (

-		cmd     = cli.Subcmd("attach", "CONTAINER", "Attach to a running container")

+		cmd     = cli.Subcmd("attach", "CONTAINER", "Attach to a running container", true)

 		noStdin = cmd.Bool([]string{"#nostdin", "-no-stdin"}, false, "Do not attach STDIN")

 		proxy   = cmd.Bool([]string{"#sig-proxy", "-sig-proxy"}, true, "Proxy all received signals to the process (non-TTY mode only). SIGCHLD, SIGKILL, and SIGSTOP are not proxied.")

 	)

 	cmd.Require(flag.Exact, 1)

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, true)

 	name := cmd.Arg(0)

 	stream, _, err := cli.call("GET", "/containers/"+name+"/json", nil, false)

@@ -1957,16 +1899,14 @@ func (cli *DockerCli) CmdAttach(args ...string) error {

 }

 func (cli *DockerCli) CmdSearch(args ...string) error {

-	cmd := cli.Subcmd("search", "TERM", "Search the Docker Hub for images")

+	cmd := cli.Subcmd("search", "TERM", "Search the Docker Hub for images", true)

 	noTrunc := cmd.Bool([]string{"#notrunc", "-no-trunc"}, false, "Don't truncate output")

 	trusted := cmd.Bool([]string{"#t", "#trusted", "#-trusted"}, false, "Only show trusted builds")

 	automated := cmd.Bool([]string{"-automated"}, false, "Only show automated builds")

 	stars := cmd.Int([]string{"s", "#stars", "-stars"}, 0, "Only displays with at least x stars")

 	cmd.Require(flag.Exact, 1)

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, true)

 	v := url.Values{}

 	v.Set("term", cmd.Arg(0))

@@ -2010,13 +1950,11 @@ func (cli *DockerCli) CmdSearch(args ...string) error {

 type ports []int

 func (cli *DockerCli) CmdTag(args ...string) error {

-	cmd := cli.Subcmd("tag", "IMAGE[:TAG] [REGISTRYHOST/][USERNAME/]NAME[:TAG]", "Tag an image into a repository")

+	cmd := cli.Subcmd("tag", "IMAGE[:TAG] [REGISTRYHOST/][USERNAME/]NAME[:TAG]", "Tag an image into a repository", true)

 	force := cmd.Bool([]string{"f", "#force", "-force"}, false, "Force")

 	cmd.Require(flag.Exact, 2)

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, true)

 	var (

 		repository, tag = parsers.ParseRepositoryTag(cmd.Arg(1))

@@ -2177,7 +2115,7 @@ func (cli *DockerCli) createContainer(config *runconfig.Config, hostConfig *runc

 }

 func (cli *DockerCli) CmdCreate(args ...string) error {

-	cmd := cli.Subcmd("create", "IMAGE [COMMAND] [ARG...]", "Create a new container")

+	cmd := cli.Subcmd("create", "IMAGE [COMMAND] [ARG...]", "Create a new container", true)

 	// These are flags not stored in Config/HostConfig

 	var (

@@ -2205,7 +2143,7 @@ func (cli *DockerCli) CmdCreate(args ...string) error {

 func (cli *DockerCli) CmdRun(args ...string) error {

 	// FIXME: just use runconfig.Parse already

-	cmd := cli.Subcmd("run", "IMAGE [COMMAND] [ARG...]", "Run a command in a new container")

+	cmd := cli.Subcmd("run", "IMAGE [COMMAND] [ARG...]", "Run a command in a new container", true)

 	// These are flags not stored in Config/HostConfig

 	var (

@@ -2221,6 +2159,7 @@ func (cli *DockerCli) CmdRun(args ...string) error {

 	)

 	config, hostConfig, cmd, err := runconfig.Parse(cmd, args)

+	// just in case the Parse does not exit

 	if err != nil {

 		return &utils.StatusError{StatusCode: 1}

 	}

@@ -2405,12 +2344,10 @@ func (cli *DockerCli) CmdRun(args ...string) error {

 }

 func (cli *DockerCli) CmdCp(args ...string) error {

-	cmd := cli.Subcmd("cp", "CONTAINER:PATH HOSTPATH", "Copy files/folders from the PATH to the HOSTPATH")

+	cmd := cli.Subcmd("cp", "CONTAINER:PATH HOSTPATH", "Copy files/folders from the PATH to the HOSTPATH", true)

 	cmd.Require(flag.Exact, 2)

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return nil

-	}

+	utils.ParseFlags(cmd, args, true)

 	var copyData engine.Env

 	info := strings.Split(cmd.Arg(0), ":")

@@ -2442,13 +2379,11 @@ func (cli *DockerCli) CmdCp(args ...string) error {

 }

 func (cli *DockerCli) CmdSave(args ...string) error {

-	cmd := cli.Subcmd("save", "IMAGE [IMAGE...]", "Save an image(s) to a tar archive (streamed to STDOUT by default)")

+	cmd := cli.Subcmd("save", "IMAGE [IMAGE...]", "Save an image(s) to a tar archive (streamed to STDOUT by default)", true)

 	outfile := cmd.String([]string{"o", "-output"}, "", "Write to an file, instead of STDOUT")

 	cmd.Require(flag.Min, 1)

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return err

-	}

+	utils.ParseFlags(cmd, args, true)

 	var (

 		output io.Writer = cli.out

@@ -2481,13 +2416,11 @@ func (cli *DockerCli) CmdSave(args ...string) error {

 }

 func (cli *DockerCli) CmdLoad(args ...string) error {

-	cmd := cli.Subcmd("load", "", "Load an image from a tar archive on STDIN")

+	cmd := cli.Subcmd("load", "", "Load an image from a tar archive on STDIN", true)

 	infile := cmd.String([]string{"i", "-input"}, "", "Read from a tar archive file, instead of STDIN")

 	cmd.Require(flag.Exact, 0)

-	if err := utils.ParseFlags(cmd, args, true); err != nil {

-		return err

-	}

+	utils.ParseFlags(cmd, args, true)

 	var (

 		input io.Reader = cli.in

@@ -2506,9 +2439,10 @@ func (cli *DockerCli) CmdLoad(args ...string) error {

 }

 func (cli *DockerCli) CmdExec(args ...string) error {

-	cmd := cli.Subcmd("exec", "CONTAINER COMMAND [ARG...]", "Run a command in a running container")

+	cmd := cli.Subcmd("exec", "CONTAINER COMMAND [ARG...]", "Run a command in a running container", true)

 	execConfig, err := runconfig.ParseExec(cmd, args)

+	// just in case the ParseExec does not exit

 	if execConfig.Container == "" || err != nil {

 		return &utils.StatusError{StatusCode: 1}

 	}

@@ -8,7 +8,10 @@ import (

 )

 // ParseFlags is a utility function that adds a help flag if withHelp is true,

-// calls cmd.Parse(args) and prints a relevant error message if there are incorrect number of arguments.

+// calls cmd.Parse(args) and prints a relevant error message if there are

+// incorrect number of arguments. It returns error only if error handling is

+// set to ContinueOnError and parsing fails. If error handling is set to

+// ExitOnError, it's safe to ignore the return value.

 // TODO: move this to a better package than utils

 func ParseFlags(cmd *flag.FlagSet, args []string, withHelp bool) error {

 	var help *bool