Minor cleanups in cli/command/container

This change does some minor cleanups in the
cli/command/container package;

- sort imports
- replace `fmt.Fprintf()` with `fmt.Fprintln()` if no formatting is used
- replace `fmt.Errorf()` with `errors.New()` if no formatting is used
- remove some redundant `else`'s

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

command/container/attach.go

@@ -1,18 +1,17 @@
 package container
 
 import (
-	"fmt"
+	"errors"
 	"io"
 	"net/http/httputil"
 
-	"golang.org/x/net/context"
-
 	"github.com/Sirupsen/logrus"
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/cli"
 	"github.com/docker/docker/cli/command"
 	"github.com/docker/docker/pkg/signal"
 	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
 )
 
 type attachOptions struct {
@@ -54,11 +53,11 @@ func runAttach(dockerCli *command.DockerCli, opts *attachOptions) error {
 	}
 
 	if !c.State.Running {
-		return fmt.Errorf("You cannot attach to a stopped container, start it first")
+		return errors.New("You cannot attach to a stopped container, start it first")
 	}
 
 	if c.State.Paused {
-		return fmt.Errorf("You cannot attach to a paused container, unpause it first")
+		return errors.New("You cannot attach to a paused container, unpause it first")
 	}
 
 	if err := dockerCli.In().CheckTty(!opts.noStdin, c.Config.Tty); err != nil {

command/container/cmd.go

@@ -1,10 +1,9 @@
 package container
 
 import (
-	"github.com/spf13/cobra"
-
 	"github.com/docker/docker/cli"
 	"github.com/docker/docker/cli/command"
+	"github.com/spf13/cobra"
 )
 
 // NewContainerCommand returns a cobra command for `container` subcommands

command/container/commit.go

@@ -3,13 +3,12 @@ package container
 import (
 	"fmt"
 
-	"golang.org/x/net/context"
-
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/cli"
 	"github.com/docker/docker/cli/command"
 	dockeropts "github.com/docker/docker/opts"
 	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
 )
 
 type commitOptions struct {

command/container/cp.go

@@ -1,20 +1,20 @@
 package container
 
 import (
+	"errors"
 	"fmt"
 	"io"
 	"os"
 	"path/filepath"
 	"strings"
 
-	"golang.org/x/net/context"
-
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/cli"
 	"github.com/docker/docker/cli/command"
 	"github.com/docker/docker/pkg/archive"
 	"github.com/docker/docker/pkg/system"
 	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
 )
 
 type copyOptions struct {
@@ -53,10 +53,10 @@ func NewCopyCommand(dockerCli *command.DockerCli) *cobra.Command {
 		Args: cli.ExactArgs(2),
 		RunE: func(cmd *cobra.Command, args []string) error {
 			if args[0] == "" {
-				return fmt.Errorf("source can not be empty")
+				return errors.New("source can not be empty")
 			}
 			if args[1] == "" {
-				return fmt.Errorf("destination can not be empty")
+				return errors.New("destination can not be empty")
 			}
 			opts.source = args[0]
 			opts.destination = args[1]
@@ -96,10 +96,10 @@ func runCopy(dockerCli *command.DockerCli, opts copyOptions) error {
 		return copyToContainer(ctx, dockerCli, srcPath, dstContainer, dstPath, cpParam)
 	case acrossContainers:
 		// Copying between containers isn't supported.
-		return fmt.Errorf("copying between containers is not supported")
+		return errors.New("copying between containers is not supported")
 	default:
 		// User didn't specify any container.
-		return fmt.Errorf("must specify at least one container source")
+		return errors.New("must specify at least one container source")
 	}
 }
 
@@ -227,7 +227,7 @@ func copyToContainer(ctx context.Context, dockerCli *command.DockerCli, srcPath,
 		content = os.Stdin
 		resolvedDstPath = dstInfo.Path
 		if !dstInfo.IsDir {
-			return fmt.Errorf("destination %q must be a directory", fmt.Sprintf("%s:%s", dstContainer, dstPath))
+			return fmt.Errorf("destination \"%s:%s\" must be a directory", dstContainer, dstPath)
 		}
 	} else {
 		// Prepare source copy info.

command/container/create.go

@@ -5,22 +5,21 @@ import (
 	"io"
 	"os"
 
-	"golang.org/x/net/context"
-
-	"github.com/docker/docker/cli"
-	"github.com/docker/docker/cli/command"
-	"github.com/docker/docker/cli/command/image"
-	"github.com/docker/docker/pkg/jsonmessage"
-	// FIXME migrate to docker/distribution/reference
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/container"
 	networktypes "github.com/docker/docker/api/types/network"
+	"github.com/docker/docker/cli"
+	"github.com/docker/docker/cli/command"
+	"github.com/docker/docker/cli/command/image"
 	apiclient "github.com/docker/docker/client"
+	"github.com/docker/docker/pkg/jsonmessage"
+	// FIXME migrate to docker/distribution/reference
 	"github.com/docker/docker/reference"
 	"github.com/docker/docker/registry"
 	runconfigopts "github.com/docker/docker/runconfig/opts"
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
+	"golang.org/x/net/context"
 )
 
 type createOptions struct {
@@ -69,7 +68,7 @@ func runCreate(dockerCli *command.DockerCli, flags *pflag.FlagSet, opts *createO
 	if err != nil {
 		return err
 	}
-	fmt.Fprintf(dockerCli.Out(), "%s\n", response.ID)
+	fmt.Fprintln(dockerCli.Out(), response.ID)
 	return nil
 }
 
@@ -118,11 +117,12 @@ type cidFile struct {
 func (cid *cidFile) Close() error {
 	cid.file.Close()
 
-	if !cid.written {
+	if cid.written {
+		return nil
+	}
 	if err := os.Remove(cid.path); err != nil {
 		return fmt.Errorf("failed to remove the CID file '%s': %s \n", cid.path, err)
 	}
-	}
 
 	return nil
 }

command/container/diff.go

@@ -1,14 +1,14 @@
 package container
 
 import (
+	"errors"
 	"fmt"
 
-	"golang.org/x/net/context"
-
 	"github.com/docker/docker/cli"
 	"github.com/docker/docker/cli/command"
 	"github.com/docker/docker/pkg/archive"
 	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
 )
 
 type diffOptions struct {
@@ -32,7 +32,7 @@ func NewDiffCommand(dockerCli *command.DockerCli) *cobra.Command {
 
 func runDiff(dockerCli *command.DockerCli, opts *diffOptions) error {
 	if opts.container == "" {
-		return fmt.Errorf("Container name cannot be empty")
+		return errors.New("Container name cannot be empty")
 	}
 	ctx := context.Background()
 
@@ -51,7 +51,7 @@ func runDiff(dockerCli *command.DockerCli, opts *diffOptions) error {
 		case archive.ChangeDelete:
 			kind = "D"
 		}
-		fmt.Fprintf(dockerCli.Out(), "%s %s\n", kind, change.Path)
+		fmt.Fprintln(dockerCli.Out(), kind, change.Path)
 	}
 
 	return nil

command/container/exec.go

@@ -4,8 +4,6 @@ import (
 	"fmt"
 	"io"
 
-	"golang.org/x/net/context"
-
 	"github.com/Sirupsen/logrus"
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/cli"
@@ -15,6 +13,7 @@ import (
 	"github.com/docker/docker/pkg/promise"
 	runconfigopts "github.com/docker/docker/runconfig/opts"
 	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
 )
 
 type execOptions struct {
@@ -88,7 +87,7 @@ func runExec(dockerCli *command.DockerCli, opts *execOptions, container string,
 
 	execID := response.ID
 	if execID == "" {
-		fmt.Fprintf(dockerCli.Out(), "exec ID empty")
+		fmt.Fprintln(dockerCli.Out(), "exec ID empty")
 		return nil
 	}
 
@@ -143,7 +142,7 @@ func runExec(dockerCli *command.DockerCli, opts *execOptions, container string,
 
 	if execConfig.Tty && dockerCli.In().IsTerminal() {
 		if err := MonitorTtySize(ctx, dockerCli, execID, true); err != nil {
-			fmt.Fprintf(dockerCli.Err(), "Error monitoring TTY size: %s\n", err)
+			fmt.Fprintln(dockerCli.Err(), "Error monitoring TTY size:", err)
 		}
 	}
 

command/container/export.go

@@ -4,11 +4,10 @@ import (
 	"errors"
 	"io"
 
-	"golang.org/x/net/context"
-
 	"github.com/docker/docker/cli"
 	"github.com/docker/docker/cli/command"
 	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
 )
 
 type exportOptions struct {

command/container/inspect.go

@@ -1,12 +1,11 @@
 package container
 
 import (
-	"golang.org/x/net/context"
-
 	"github.com/docker/docker/cli"
 	"github.com/docker/docker/cli/command"
 	"github.com/docker/docker/cli/command/inspect"
 	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
 )
 
 type inspectOptions struct {

command/container/kill.go

@@ -1,14 +1,14 @@
 package container
 
 import (
+	"errors"
 	"fmt"
 	"strings"
 
-	"golang.org/x/net/context"
-
 	"github.com/docker/docker/cli"
 	"github.com/docker/docker/cli/command"
 	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
 )
 
 type killOptions struct {
@@ -46,11 +46,11 @@ func runKill(dockerCli *command.DockerCli, opts *killOptions) error {
 		if err := <-errChan; err != nil {
 			errs = append(errs, err.Error())
 		} else {
-			fmt.Fprintf(dockerCli.Out(), "%s\n", name)
+			fmt.Fprintln(dockerCli.Out(), name)
 		}
 	}
 	if len(errs) > 0 {
-		return fmt.Errorf("%s", strings.Join(errs, "\n"))
+		return errors.New(strings.Join(errs, "\n"))
 	}
 	return nil
 }

command/container/list.go

@@ -3,8 +3,6 @@ package container
 import (
 	"io/ioutil"
 
-	"golang.org/x/net/context"
-
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/cli"
 	"github.com/docker/docker/cli/command"
@@ -12,6 +10,7 @@ import (
 	"github.com/docker/docker/opts"
 	"github.com/docker/docker/pkg/templates"
 	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
 )
 
 type psOptions struct {

command/container/logs.go

@@ -3,13 +3,12 @@ package container
 import (
 	"io"
 
-	"golang.org/x/net/context"
-
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/cli"
 	"github.com/docker/docker/cli/command"
 	"github.com/docker/docker/pkg/stdcopy"
 	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
 )
 
 type logsOptions struct {

command/container/pause.go

@@ -1,14 +1,14 @@
 package container
 
 import (
+	"errors"
 	"fmt"
 	"strings"
 
-	"golang.org/x/net/context"
-
 	"github.com/docker/docker/cli"
 	"github.com/docker/docker/cli/command"
 	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
 )
 
 type pauseOptions struct {
@@ -38,12 +38,12 @@ func runPause(dockerCli *command.DockerCli, opts *pauseOptions) error {
 	for _, container := range opts.containers {
 		if err := <-errChan; err != nil {
 			errs = append(errs, err.Error())
-		} else {
-			fmt.Fprintf(dockerCli.Out(), "%s\n", container)
+			continue
 		}
+		fmt.Fprintln(dockerCli.Out(), container)
 	}
 	if len(errs) > 0 {
-		return fmt.Errorf("%s", strings.Join(errs, "\n"))
+		return errors.New(strings.Join(errs, "\n"))
 	}
 	return nil
 }

command/container/port.go

@@ -4,12 +4,11 @@ import (
 	"fmt"
 	"strings"
 
-	"golang.org/x/net/context"
-
 	"github.com/docker/docker/cli"
 	"github.com/docker/docker/cli/command"
 	"github.com/docker/go-connections/nat"
 	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
 )
 
 type portOptions struct {

command/container/prune.go

@@ -3,13 +3,12 @@ package container
 import (
 	"fmt"
 
-	"golang.org/x/net/context"
-
 	"github.com/docker/docker/api/types/filters"
 	"github.com/docker/docker/cli"
 	"github.com/docker/docker/cli/command"
 	units "github.com/docker/go-units"
 	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
 )
 
 type pruneOptions struct {

command/container/rename.go

@@ -1,14 +1,14 @@
 package container
 
 import (
+	"errors"
 	"fmt"
 	"strings"
 
-	"golang.org/x/net/context"
-
 	"github.com/docker/docker/cli"
 	"github.com/docker/docker/cli/command"
 	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
 )
 
 type renameOptions struct {
@@ -40,11 +40,11 @@ func runRename(dockerCli *command.DockerCli, opts *renameOptions) error {
 	newName := strings.TrimSpace(opts.newName)
 
 	if oldName == "" || newName == "" {
-		return fmt.Errorf("Error: Neither old nor new names may be empty")
+		return errors.New("Error: Neither old nor new names may be empty")
 	}
 
 	if err := dockerCli.Client().ContainerRename(ctx, oldName, newName); err != nil {
-		fmt.Fprintf(dockerCli.Err(), "%s\n", err)
+		fmt.Fprintln(dockerCli.Err(), err)
 		return fmt.Errorf("Error: failed to rename container named %s", oldName)
 	}
 	return nil

command/container/restart.go

@@ -1,15 +1,15 @@
 package container
 
 import (
+	"errors"
 	"fmt"
 	"strings"
 	"time"
 
-	"golang.org/x/net/context"
-
 	"github.com/docker/docker/cli"
 	"github.com/docker/docker/cli/command"
 	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
 )
 
 type restartOptions struct {
@@ -51,12 +51,12 @@ func runRestart(dockerCli *command.DockerCli, opts *restartOptions) error {
 	for _, name := range opts.containers {
 		if err := dockerCli.Client().ContainerRestart(ctx, name, timeout); err != nil {
 			errs = append(errs, err.Error())
-		} else {
-			fmt.Fprintf(dockerCli.Out(), "%s\n", name)
+			continue
 		}
+		fmt.Fprintln(dockerCli.Out(), name)
 	}
 	if len(errs) > 0 {
-		return fmt.Errorf("%s", strings.Join(errs, "\n"))
+		return errors.New(strings.Join(errs, "\n"))
 	}
 	return nil
 }

command/container/rm.go

@@ -1,15 +1,15 @@
 package container
 
 import (
+	"errors"
 	"fmt"
 	"strings"
 
-	"golang.org/x/net/context"
-
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/cli"
 	"github.com/docker/docker/cli/command"
 	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
 )
 
 type rmOptions struct {
@@ -52,22 +52,22 @@ func runRm(dockerCli *command.DockerCli, opts *rmOptions) error {
 	}
 
 	errChan := parallelOperation(ctx, opts.containers, func(ctx context.Context, container string) error {
-		if container == "" {
-			return fmt.Errorf("Container name cannot be empty")
-		}
 		container = strings.Trim(container, "/")
+		if container == "" {
+			return errors.New("Container name cannot be empty")
+		}
 		return dockerCli.Client().ContainerRemove(ctx, container, options)
 	})
 
 	for _, name := range opts.containers {
 		if err := <-errChan; err != nil {
 			errs = append(errs, err.Error())
-		} else {
-			fmt.Fprintf(dockerCli.Out(), "%s\n", name)
+			continue
 		}
+		fmt.Fprintln(dockerCli.Out(), name)
 	}
 	if len(errs) > 0 {
-		return fmt.Errorf("%s", strings.Join(errs, "\n"))
+		return errors.New(strings.Join(errs, "\n"))
 	}
 	return nil
 }

command/container/run.go

@@ -1,6 +1,7 @@
 package container
 
 import (
+	"errors"
 	"fmt"
 	"io"
 	"net/http/httputil"
@@ -9,8 +10,6 @@ import (
 	"strings"
 	"syscall"
 
-	"golang.org/x/net/context"
-
 	"github.com/Sirupsen/logrus"
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/cli"
@@ -22,6 +21,7 @@ import (
 	"github.com/docker/libnetwork/resolvconf/dns"
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
+	"golang.org/x/net/context"
 )
 
 type runOptions struct {
@@ -75,8 +75,8 @@ func runRun(dockerCli *command.DockerCli, flags *pflag.FlagSet, opts *runOptions
 
 	var (
 		flAttach                              *opttypes.ListOpts
-		ErrConflictAttachDetach               = fmt.Errorf("Conflicting options: -a and -d")
-		ErrConflictRestartPolicyAndAutoRemove = fmt.Errorf("Conflicting options: --restart and --rm")
+		ErrConflictAttachDetach               = errors.New("Conflicting options: -a and -d")
+		ErrConflictRestartPolicyAndAutoRemove = errors.New("Conflicting options: --restart and --rm")
 	)
 
 	config, hostConfig, networkingConfig, err := runconfigopts.Parse(flags, copts)
@@ -91,7 +91,7 @@ func runRun(dockerCli *command.DockerCli, flags *pflag.FlagSet, opts *runOptions
 		return ErrConflictRestartPolicyAndAutoRemove
 	}
 	if hostConfig.OomKillDisable != nil && *hostConfig.OomKillDisable && hostConfig.Memory == 0 {
-		fmt.Fprintf(stderr, "WARNING: Disabling the OOM killer on containers without setting a '-m/--memory' limit may be dangerous.\n")
+		fmt.Fprintln(stderr, "WARNING: Disabling the OOM killer on containers without setting a '-m/--memory' limit may be dangerous.")
 	}
 
 	if len(hostConfig.DNS) > 0 {
@@ -158,7 +158,7 @@ func runRun(dockerCli *command.DockerCli, flags *pflag.FlagSet, opts *runOptions
 		waitDisplayID = make(chan struct{})
 		go func() {
 			defer close(waitDisplayID)
-			fmt.Fprintf(stdout, "%s\n", createResponse.ID)
+			fmt.Fprintln(stdout, createResponse.ID)
 		}()
 	}
 	attach := config.AttachStdin || config.AttachStdout || config.AttachStderr
@@ -203,11 +203,10 @@ func runRun(dockerCli *command.DockerCli, flags *pflag.FlagSet, opts *runOptions
 		defer resp.Close()
 
 		errCh = promise.Go(func() error {
-			errHijack := holdHijackedConnection(ctx, dockerCli, config.Tty, in, out, cerr, resp)
-			if errHijack == nil {
-				return errAttach
-			}
+			if errHijack := holdHijackedConnection(ctx, dockerCli, config.Tty, in, out, cerr, resp); errHijack != nil {
 				return errHijack
+			}
+			return errAttach
 		})
 	}
 
@@ -233,7 +232,7 @@ func runRun(dockerCli *command.DockerCli, flags *pflag.FlagSet, opts *runOptions
 
 	if (config.AttachStdin || config.AttachStdout || config.AttachStderr) && config.Tty && dockerCli.Out().IsTerminal() {
 		if err := MonitorTtySize(ctx, dockerCli, createResponse.ID, false); err != nil {
-			fmt.Fprintf(stderr, "Error monitoring TTY size: %s\n", err)
+			fmt.Fprintln(stderr, "Error monitoring TTY size:", err)
 		}
 	}
 

command/container/start.go

@@ -1,19 +1,19 @@
 package container
 
 import (
+	"errors"
 	"fmt"
 	"io"
 	"net/http/httputil"
 	"strings"
 
-	"golang.org/x/net/context"
-
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/cli"
 	"github.com/docker/docker/cli/command"
 	"github.com/docker/docker/pkg/promise"
 	"github.com/docker/docker/pkg/signal"
 	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
 )
 
 type startOptions struct {
@@ -59,7 +59,7 @@ func runStart(dockerCli *command.DockerCli, opts *startOptions) error {
 		// We're going to attach to a container.
 		// 1. Ensure we only have one container.
 		if len(opts.containers) > 1 {
-			return fmt.Errorf("You cannot start and attach multiple containers at once.")
+			return errors.New("You cannot start and attach multiple containers at once.")
 		}
 
 		// 2. Attach to the container.
@@ -131,7 +131,7 @@ func runStart(dockerCli *command.DockerCli, opts *startOptions) error {
 		// 5. Wait for attachment to break.
 		if c.Config.Tty && dockerCli.Out().IsTerminal() {
 			if err := MonitorTtySize(ctx, dockerCli, c.ID, false); err != nil {
-				fmt.Fprintf(dockerCli.Err(), "Error monitoring TTY size: %s\n", err)
+				fmt.Fprintln(dockerCli.Err(), "Error monitoring TTY size:", err)
 			}
 		}
 		if attchErr := <-cErr; attchErr != nil {
@@ -143,7 +143,7 @@ func runStart(dockerCli *command.DockerCli, opts *startOptions) error {
 		}
 	} else if opts.checkpoint != "" {
 		if len(opts.containers) > 1 {
-			return fmt.Errorf("You cannot restore multiple containers at once.")
+			return errors.New("You cannot restore multiple containers at once.")
 		}
 		container := opts.containers[0]
 		startOptions := types.ContainerStartOptions{
@@ -165,15 +165,15 @@ func startContainersWithoutAttachments(ctx context.Context, dockerCli *command.D
 	var failedContainers []string
 	for _, container := range containers {
 		if err := dockerCli.Client().ContainerStart(ctx, container, types.ContainerStartOptions{}); err != nil {
-			fmt.Fprintf(dockerCli.Err(), "%s\n", err)
+			fmt.Fprintln(dockerCli.Err(), err)
 			failedContainers = append(failedContainers, container)
-		} else {
-			fmt.Fprintf(dockerCli.Out(), "%s\n", container)
+			continue
 		}
+		fmt.Fprintln(dockerCli.Out(), container)
 	}
 
 	if len(failedContainers) > 0 {
-		return fmt.Errorf("Error: failed to start containers: %v", strings.Join(failedContainers, ", "))
+		return fmt.Errorf("Error: failed to start containers: %s", strings.Join(failedContainers, ", "))
 	}
 	return nil
 }

command/container/stats.go

@@ -1,14 +1,13 @@
 package container
 
 import (
+	"errors"
 	"fmt"
 	"io"
 	"strings"
 	"sync"
 	"time"
 
-	"golang.org/x/net/context"
-
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/events"
 	"github.com/docker/docker/api/types/filters"
@@ -16,6 +15,7 @@ import (
 	"github.com/docker/docker/cli/command"
 	"github.com/docker/docker/cli/command/formatter"
 	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
 )
 
 type statsOptions struct {
@@ -179,7 +179,7 @@ func runStats(dockerCli *command.DockerCli, opts *statsOptions) error {
 		}
 		cStats.mu.Unlock()
 		if len(errs) > 0 {
-			return fmt.Errorf("%s", strings.Join(errs, "\n"))
+			return errors.New(strings.Join(errs, "\n"))
 		}
 	}
 

command/container/stop.go

@@ -1,15 +1,15 @@
 package container
 
 import (
+	"errors"
 	"fmt"
 	"strings"
 	"time"
 
-	"golang.org/x/net/context"
-
 	"github.com/docker/docker/cli"
 	"github.com/docker/docker/cli/command"
 	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
 )
 
 type stopOptions struct {
@@ -56,12 +56,12 @@ func runStop(dockerCli *command.DockerCli, opts *stopOptions) error {
 	for _, container := range opts.containers {
 		if err := <-errChan; err != nil {
 			errs = append(errs, err.Error())
-		} else {
-			fmt.Fprintf(dockerCli.Out(), "%s\n", container)
+			continue
 		}
+		fmt.Fprintln(dockerCli.Out(), container)
 	}
 	if len(errs) > 0 {
-		return fmt.Errorf("%s", strings.Join(errs, "\n"))
+		return errors.New(strings.Join(errs, "\n"))
 	}
 	return nil
 }

command/container/top.go

@@ -5,11 +5,10 @@ import (
 	"strings"
 	"text/tabwriter"
 
-	"golang.org/x/net/context"
-
 	"github.com/docker/docker/cli"
 	"github.com/docker/docker/cli/command"
 	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
 )
 
 type topOptions struct {

command/container/unpause.go

@@ -1,14 +1,14 @@
 package container
 
 import (
+	"errors"
 	"fmt"
 	"strings"
 
-	"golang.org/x/net/context"
-
 	"github.com/docker/docker/cli"
 	"github.com/docker/docker/cli/command"
 	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
 )
 
 type unpauseOptions struct {
@@ -39,12 +39,12 @@ func runUnpause(dockerCli *command.DockerCli, opts *unpauseOptions) error {
 	for _, container := range opts.containers {
 		if err := <-errChan; err != nil {
 			errs = append(errs, err.Error())
-		} else {
-			fmt.Fprintf(dockerCli.Out(), "%s\n", container)
+			continue
 		}
+		fmt.Fprintln(dockerCli.Out(), container)
 	}
 	if len(errs) > 0 {
-		return fmt.Errorf("%s", strings.Join(errs, "\n"))
+		return errors.New(strings.Join(errs, "\n"))
 	}
 	return nil
 }

command/container/update.go

@@ -1,17 +1,17 @@
 package container
 
 import (
+	"errors"
 	"fmt"
 	"strings"
 
-	"golang.org/x/net/context"
-
 	containertypes "github.com/docker/docker/api/types/container"
 	"github.com/docker/docker/cli"
 	"github.com/docker/docker/cli/command"
 	runconfigopts "github.com/docker/docker/runconfig/opts"
 	"github.com/docker/go-units"
 	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
 )
 
 type updateOptions struct {
@@ -71,7 +71,7 @@ func runUpdate(dockerCli *command.DockerCli, opts *updateOptions) error {
 	var err error
 
 	if opts.nFlag == 0 {
-		return fmt.Errorf("You must provide one or more flags when using this command.")
+		return errors.New("You must provide one or more flags when using this command.")
 	}
 
 	var memory int64
@@ -149,15 +149,15 @@ func runUpdate(dockerCli *command.DockerCli, opts *updateOptions) error {
 		if err != nil {
 			errs = append(errs, err.Error())
 		} else {
-			fmt.Fprintf(dockerCli.Out(), "%s\n", container)
+			fmt.Fprintln(dockerCli.Out(), container)
 		}
 		warns = append(warns, r.Warnings...)
 	}
 	if len(warns) > 0 {
-		fmt.Fprintf(dockerCli.Out(), "%s", strings.Join(warns, "\n"))
+		fmt.Fprintln(dockerCli.Out(), strings.Join(warns, "\n"))
 	}
 	if len(errs) > 0 {
-		return fmt.Errorf("%s", strings.Join(errs, "\n"))
+		return errors.New(strings.Join(errs, "\n"))
 	}
 	return nil
 }

command/container/utils.go

@@ -3,8 +3,6 @@ package container
 import (
 	"strconv"
 
-	"golang.org/x/net/context"
-
 	"github.com/Sirupsen/logrus"
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/events"
@@ -12,6 +10,7 @@ import (
 	"github.com/docker/docker/api/types/versions"
 	"github.com/docker/docker/cli/command"
 	clientapi "github.com/docker/docker/client"
+	"golang.org/x/net/context"
 )
 
 func waitExitOrRemoved(ctx context.Context, dockerCli *command.DockerCli, containerID string, waitRemove bool) chan int {

command/container/wait.go

@@ -1,14 +1,14 @@
 package container
 
 import (
+	"errors"
 	"fmt"
 	"strings"
 
-	"golang.org/x/net/context"
-
 	"github.com/docker/docker/cli"
 	"github.com/docker/docker/cli/command"
 	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
 )
 
 type waitOptions struct {
@@ -39,12 +39,12 @@ func runWait(dockerCli *command.DockerCli, opts *waitOptions) error {
 		status, err := dockerCli.Client().ContainerWait(ctx, container)
 		if err != nil {
 			errs = append(errs, err.Error())
-		} else {
+			continue
+		}
 		fmt.Fprintf(dockerCli.Out(), "%d\n", status)
 	}
-	}
 	if len(errs) > 0 {
-		return fmt.Errorf("%s", strings.Join(errs, "\n"))
+		return errors.New(strings.Join(errs, "\n"))
 	}
 	return nil
 }