Merge pull request #714 from github/exec_cmd

Use `Exec` except Windows for the last command run in the commands chain

cmd/cmd.go

@@ -2,11 +2,14 @@ package cmd
 
 import (
 	"fmt"
-	"github.com/github/hub/utils"
-	"github.com/github/hub/Godeps/_workspace/src/github.com/kballard/go-shellquote"
 	"os"
 	"os/exec"
+	"runtime"
 	"strings"
+	"syscall"
+
+	"github.com/github/hub/Godeps/_workspace/src/github.com/kballard/go-shellquote"
+	"github.com/github/hub/utils"
 )
 
 type Cmd struct {
@@ -34,19 +37,25 @@ func (cmd *Cmd) WithArgs(args ...string) *Cmd {
 	return cmd
 }
 
-func (cmd *Cmd) ExecOutput() (string, error) {
+func (cmd *Cmd) CombinedOutput() (string, error) {
 	output, err := exec.Command(cmd.Name, cmd.Args...).CombinedOutput()
 
 	return string(output), err
 }
 
-func (cmd *Cmd) Exec() error {
-	binary, lookErr := exec.LookPath(cmd.Name)
-	if lookErr != nil {
-		return fmt.Errorf("command not found: %s", cmd.Name)
+// Run runs command with `Exec` on platforms except Windows
+// which only supports `Spawn`
+func (cmd *Cmd) Run() error {
+	if runtime.GOOS == "windows" {
+		return cmd.Spawn()
+	} else {
+		return cmd.Exec()
 	}
+}
 
-	c := exec.Command(binary, cmd.Args...)
+// Spawn runs command with spawn(3)
+func (cmd *Cmd) Spawn() error {
+	c := exec.Command(cmd.Name, cmd.Args...)
 	c.Stdin = os.Stdin
 	c.Stdout = os.Stdout
 	c.Stderr = os.Stderr
@@ -54,6 +63,20 @@ func (cmd *Cmd) Exec() error {
 	return c.Run()
 }
 
+// Exec runs command with exec(3)
+// Note that Windows doesn't support exec(3): http://golang.org/src/pkg/syscall/exec_windows.go#L339
+func (cmd *Cmd) Exec() error {
+	binary, err := exec.LookPath(cmd.Name)
+	if err != nil {
+		return fmt.Errorf("command not found: %s", cmd.Name)
+	}
+
+	args := []string{binary}
+	args = append(args, cmd.Args...)
+
+	return syscall.Exec(binary, args, os.Environ())
+}
+
 func New(cmd string) *Cmd {
 	cmds, err := shellquote.Split(cmd)
 	utils.Check(err)

commands/runner.go

@@ -7,11 +7,11 @@ import (
 	"strings"
 	"syscall"
 
+	"github.com/github/hub/Godeps/_workspace/src/github.com/kballard/go-shellquote"
+	flag "github.com/github/hub/Godeps/_workspace/src/github.com/ogier/pflag"
 	"github.com/github/hub/cmd"
 	"github.com/github/hub/git"
 	"github.com/github/hub/utils"
-	"github.com/github/hub/Godeps/_workspace/src/github.com/kballard/go-shellquote"
-	flag "github.com/github/hub/Godeps/_workspace/src/github.com/ogier/pflag"
 )
 
 type ExecError struct {
@@ -76,7 +76,7 @@ func (r *Runner) Execute() ExecError {
 		return r.Call(cmd, args)
 	}
 
-	err = git.Spawn(args.Command, args.Params...)
+	err = git.Run(args.Command, args.Params...)
 	return newExecError(err)
 }
 
@@ -106,8 +106,15 @@ func printCommands(cmds []*cmd.Cmd) {
 }
 
 func executeCommands(cmds []*cmd.Cmd) error {
-	for _, c := range cmds {
-		err := c.Exec()
+	for i, c := range cmds {
+		var err error
+		// Run with `Exec` for the last command in chain
+		if i == len(cmds)-1 {
+			err = c.Run()
+		} else {
+			err = c.Spawn()
+		}
+
 		if err != nil {
 			return err
 		}

fixtures/test_repo.go

@@ -48,7 +48,7 @@ func (r *TestRepo) Setup() {
 
 func (r *TestRepo) clone(repo, dir string) error {
 	cmd := cmd.New("git").WithArgs("clone", repo, dir)
-	output, err := cmd.ExecOutput()
+	output, err := cmd.CombinedOutput()
 	if err != nil {
 		err = fmt.Errorf("error cloning %s to %s: %s", repo, dir, output)
 	}

git/git.go

@@ -130,7 +130,7 @@ func Show(sha string) (string, error) {
 	cmd := cmd.New("git")
 	cmd.WithArg("show").WithArg("-s").WithArg("--format=%s%n%+b").WithArg(sha)
 
-	output, err := cmd.ExecOutput()
+	output, err := cmd.CombinedOutput()
 	output = strings.TrimSpace(output)
 
 	return output, err
@@ -144,7 +144,7 @@ func Log(sha1, sha2 string) (string, error) {
 	shaRange := fmt.Sprintf("%s...%s", sha1, sha2)
 	execCmd.WithArg(shaRange)
 
-	outputs, err := execCmd.ExecOutput()
+	outputs, err := execCmd.CombinedOutput()
 	if err != nil {
 		return "", fmt.Errorf("Can't load git log %s..%s", sha1, sha2)
 	}
@@ -191,14 +191,14 @@ func Alias(name string) (string, error) {
 	return Config(fmt.Sprintf("alias.%s", name))
 }
 
-func Spawn(command string, args ...string) error {
+func Run(command string, args ...string) error {
 	cmd := cmd.New("git")
 	cmd.WithArg(command)
 	for _, a := range args {
 		cmd.WithArg(a)
 	}
 
-	return cmd.Exec()
+	return cmd.Run()
 }
 
 func execGitCmd(input ...string) (outputs []string, err error) {
@@ -207,7 +207,7 @@ func execGitCmd(input ...string) (outputs []string, err error) {
 		cmd.WithArg(i)
 	}
 
-	out, err := cmd.ExecOutput()
+	out, err := cmd.CombinedOutput()
 	for _, line := range strings.Split(out, "\n") {
 		line = strings.TrimSpace(line)
 		if line != "" {

github/editor.go

@@ -118,7 +118,7 @@ func openTextEditor(program, file string) error {
 	}
 	editCmd.WithArg(file)
 
-	return editCmd.Exec()
+	return editCmd.Spawn()
 }
 
 func readTitleAndBody(reader io.Reader, cs string) (title, body string, err error) {