@@ -10,7 +10,6 @@ import (

 	"log"

 	"net/http"

 	"net/url"

-	"os"

 	"runtime"

 	"strconv"

 	"strings"

@@ -34,7 +33,7 @@ func (srv *Server) Help() string {

 	help := "Usage: docker COMMAND [arg...]\n\nA self-sufficient runtime for linux containers.\n\nCommands:\n"

 	for _, cmd := range [][]string{

 		{"attach", "Attach to a running container"},

-		{"build", "Build a container from Dockerfile"},

+		{"build", "Build a container from Dockerfile via stdin"},

 		{"commit", "Create a new image from a container's changes"},

 		{"diff", "Inspect changes on a container's filesystem"},

 		{"export", "Stream the contents of a container as a tar archive"},

@@ -115,28 +114,11 @@ func (srv *Server) CmdInsert(stdin io.ReadCloser, stdout rcli.DockerConn, args .

 func (srv *Server) CmdBuild(stdin io.ReadCloser, stdout rcli.DockerConn, args ...string) error {

 	stdout.Flush()

-	cmd := rcli.Subcmd(stdout, "build", "[Dockerfile|-]", "Build a container from Dockerfile")

+	cmd := rcli.Subcmd(stdout, "build", "-", "Build a container from Dockerfile via stdin")

 	if err := cmd.Parse(args); err != nil {

 		return nil

 	}

-	dockerfile := cmd.Arg(0)

-	if dockerfile == "" {

-		dockerfile = "Dockerfile"

-	}

-

-	var file io.Reader

-

-	if dockerfile != "-" {

-		f, err := os.Open(dockerfile)

-		if err != nil {

-			return err

-		}

-		defer f.Close()

-		file = f

-	} else {

-		file = stdin

-	}

-	img, err := NewBuilder(srv.runtime).Build(file, stdout)

+	img, err := NewBuilder(srv.runtime).Build(stdin, stdout)

 	if err != nil {

 		return err

 	}