func ExampleCommandContext() {
ctx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
defer cancel()
if err := exec.CommandContext(ctx, "sleep", "5").Run(); err != nil {
// This will fail after 100 milliseconds. The 5 second sleep
// will be interrupted.
}
}
func ping(ctx context.Context, ip string) {
cmd := exec.CommandContext(ctx, "ping", ip, "-t")
cmd.Stdout = os.Stdin
go cmd.Run()
<-ctx.Done()
fmt.Println("接收到退出消息", cmd.Process.Pid)
cmd.Process.Kill()
}
func main() {
opt, args := parseFlags()
if opt.listBundledLSPs {
// Print out bundled LSPs
for b := range bundles {
fmt.Println(b)
}
os.Exit(0)
}
var err error
lsp, err = loadLogSchemePack(args[0])
exitIf(err)
if opt.dumpLSP {
// Print out lsp in JSON format
lsp.MarshalToJson(os.Stdout)
os.Exit(0)
}
ctx, cancle := context.WithCancel(context.Background())
defer cancle()
args = args[1:]
if len(args) > 0 {
// command given as args
cmd := exec.CommandContext(ctx, args[0], args[1:]...)
cStdOut, err := cmd.StdoutPipe()
exitIf(err)
cStdErr, err := cmd.StderrPipe()
exitIf(err)
cmd.Start()
go paintLines(ctx, cStdOut, "stdout")
go paintLines(ctx, cStdErr, "stderr")
err = <-errC
exitIf(err)
err = <-errC
exitIf(err)
cmd.Wait()
} else {
// log is given through stdin
go paintLines(ctx, os.Stdin, "stdout")
err = <-errC
exitIf(err)
}
}
func helperCommandContext(t *testing.T, ctx context.Context, s ...string) (cmd *exec.Cmd) {
testenv.MustHaveExec(t)
cs := []string{"-test.run=TestHelperProcess", "--"}
cs = append(cs, s...)
if ctx != nil {
cmd = exec.CommandContext(ctx, os.Args[0], cs...)
} else {
cmd = exec.Command(os.Args[0], cs...)
}
cmd.Env = []string{"GO_WANT_HELPER_PROCESS=1"}
return cmd
}
func main() {
ctx, cancel := context.WithCancel(context.Background())
cmd := exec.CommandContext(ctx, "./b")
cmd.SysProcAttr = &syscall.SysProcAttr{HideWindow: true}
cmd.Stdout = os.Stdout
cmd.Start()
time.Sleep(10 * time.Second)
fmt.Println("退出程序中...", cmd.Process.Pid)
cancel()
cmd.Wait()
}
func (m *iManIP) DoCmd(cmd string) error {
if len(cmd) == 0 {
return errors.New("The cmd can't be empty!")
}
if m.ctx == nil {
m.ctx = context.Background()
}
command := strings.Split(cmd, " ")
m.Cmd = exec.CommandContext(m.ctx, command[0], command[1:]...)
m.SysProcAttr = &syscall.SysProcAttr{HideWindow: true}
return nil
}
// fail because load didn't receive data from stdin
func (s *DockerSuite) TestLoadNoStdinFail(c *check.C) {
pty, tty, err := pty.Open()
c.Assert(err, check.IsNil)
ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
defer cancel()
cmd := exec.CommandContext(ctx, dockerBinary, "load")
cmd.Stdin = tty
cmd.Stdout = tty
cmd.Stderr = tty
c.Assert(cmd.Run(), check.NotNil) // docker-load should fail
buf := make([]byte, 1024)
n, err := pty.Read(buf)
c.Assert(err, check.IsNil) //could not read tty output
c.Assert(string(buf[:n]), checker.Contains, "requested load from stdin, but stdin is empty")
}
func main() {
if len(os.Args) < 3 {
fmt.Fprintf(os.Stderr,
"Usage: %s <timeout-in-sec> <command ...>\n", os.Args[0])
os.Exit(1)
}
timeout, err := strconv.ParseUint(os.Args[1], 10, 32)
if err != nil {
fmt.Fprintf(os.Stderr, "Error: %v\n", err)
os.Exit(1)
}
ctx, _ := context.WithTimeout(context.Background(), time.Duration(timeout)*time.Second)
cmd := exec.CommandContext(ctx, os.Args[2], os.Args[3:]...)
cmd.Stdin = os.Stdin
cmd.Stdout = os.Stdout
cmd.Stderr = os.Stderr
err = cmd.Start()
if err != nil {
fmt.Fprintf(os.Stderr, "Error: %v\n", err)
}
err = cmd.Wait()
if err != nil {
if ctx.Err() != nil {
os.Exit(124)
} else {
exitErr, ok := err.(*exec.ExitError)
if !ok {
fmt.Fprintf(os.Stderr, "Error: %v\n", err)
os.Exit(255)
}
waits, ok := exitErr.Sys().(syscall.WaitStatus)
if !ok {
fmt.Fprintf(os.Stderr, "Error: %v\n", err)
os.Exit(255)
}
os.Exit(waits.ExitStatus())
}
} else {
os.Exit(0)
}
}
// ExecWithTimeout runs an external command with a timeout.
// If the command times out the returned error will be a context.DeadlineExceeded error.
// If showOutput is true then output will be printed to stderr as well as returned.
// It returns the stdout only, combined stdout and stderr and any error that occurred.
func ExecWithTimeout(dir string, env []string, timeout time.Duration, defaultTimeout cli.Duration, showOutput bool, argv []string) ([]byte, []byte, error) {
if timeout == 0 {
timeout = time.Duration(defaultTimeout)
}
ctx, cancel := context.WithTimeout(context.Background(), timeout)
defer cancel()
cmd := exec.CommandContext(ctx, argv[0], argv[1:]...)
cmd.Dir = dir
cmd.Env = env
var out bytes.Buffer
var outerr safeBuffer
if showOutput {
cmd.Stdout = io.MultiWriter(os.Stderr, &out, &outerr)
cmd.Stderr = io.MultiWriter(os.Stderr, &outerr)
} else {
cmd.Stdout = io.MultiWriter(&out, &outerr)
cmd.Stderr = &outerr
}
err := cmd.Run()
return out.Bytes(), outerr.Bytes(), err
}