src/os/signal/signal_cgo_test.go - go - Git at Google

 // Copyright 2017 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.

 // +build darwin dragonfly freebsd linux,!android netbsd openbsd
 // +build cgo

 // Note that this test does not work on Solaris: issue #22849.
 // Don't run the test on Android because at least some versions of the
 // C library do not define the posix_openpt function.

 package signal_test

 import (
 	"bufio"
 	"bytes"
 	"context"
 	"fmt"
 	"io"
 	"os"
 	"os/exec"
 	"os/signal/internal/pty"
 	"strconv"
 	"strings"
 	"sync"
 	"syscall"
 	"testing"
 	"time"
 )

 func TestTerminalSignal(t *testing.T) {
 	const enteringRead = "test program entering read"
 	if os.Getenv("GO_TEST_TERMINAL_SIGNALS") != "" {
 		var b [1]byte
 		fmt.Println(enteringRead)
 		n, err := os.Stdin.Read(b[:])
 		if n == 1 {
 			if b[0] == '\n' {
 				// This is what we expect
 				fmt.Println("read newline")
 			} else {
 				fmt.Printf("read 1 byte: %q\n", b)
 			}
 		} else {
 			fmt.Printf("read %d bytes\n", n)
 		}
 		if err != nil {
 			fmt.Println(err)
 			os.Exit(1)
 		}
 		os.Exit(0)
 	}

 	t.Parallel()

 	// The test requires a shell that uses job control.
 	bash, err := exec.LookPath("bash")
 	if err != nil {
 		t.Skipf("could not find bash: %v", err)
 	}

 	scale := 1
 	if s := os.Getenv("GO_TEST_TIMEOUT_SCALE"); s != "" {
 		if sc, err := strconv.Atoi(s); err == nil {
 			scale = sc
 		}
 	}
 	pause := time.Duration(scale) * 10 * time.Millisecond
 	wait := time.Duration(scale) * 5 * time.Second

 	// The test only fails when using a "slow device," in this
 	// case a pseudo-terminal.

 	master, sname, err := pty.Open()
 	if err != nil {
 		ptyErr := err.(*pty.PtyError)
 		if ptyErr.FuncName == "posix_openpt" && ptyErr.Errno == syscall.EACCES {
 			t.Skip("posix_openpt failed with EACCES, assuming chroot and skipping")
 		}
 		t.Fatal(err)
 	}
 	defer master.Close()
 	slave, err := os.OpenFile(sname, os.O_RDWR, 0)
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer slave.Close()

 	// Start an interactive shell.
 	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
 	defer cancel()
 	cmd := exec.CommandContext(ctx, bash, "--norc", "--noprofile", "-i")
 	// Clear HISTFILE so that we don't read or clobber the user's bash history.
 	cmd.Env = append(os.Environ(), "HISTFILE=")
 	cmd.Stdin = slave
 	cmd.Stdout = slave
 	cmd.Stderr = slave
 	cmd.SysProcAttr = &syscall.SysProcAttr{
 		Setsid:  true,
 		Setctty: true,
 		Ctty:    int(slave.Fd()),
 	}

 	if err := cmd.Start(); err != nil {
 		t.Fatal(err)
 	}

 	if err := slave.Close(); err != nil {
 		t.Errorf("closing slave: %v", err)
 	}

 	progReady := make(chan bool)
 	sawPrompt := make(chan bool, 10)
 	const prompt = "prompt> "

 	// Read data from master in the background.
 	var wg sync.WaitGroup
 	wg.Add(1)
 	defer wg.Wait()
 	go func() {
 		defer wg.Done()
 		input := bufio.NewReader(master)
 		var line, handled []byte
 		for {
 			b, err := input.ReadByte()
 			if err != nil {
 				if len(line) > 0 || len(handled) > 0 {
 					t.Logf("%q", append(handled, line...))
 				}
 				if perr, ok := err.(*os.PathError); ok {
 					err = perr.Err
 				}
 				// EOF means master is closed.
 				// EIO means child process is done.
 				// "file already closed" means deferred close of master has happened.
 				if err != io.EOF && err != syscall.EIO && !strings.Contains(err.Error(), "file already closed") {
 					t.Logf("error reading from master: %v", err)
 				}
 				return
 			}

 			line = append(line, b)

 			if b == '\n' {
 				t.Logf("%q", append(handled, line...))
 				line = nil
 				handled = nil
 				continue
 			}

 			if bytes.Contains(line, []byte(enteringRead)) {
 				close(progReady)
 				handled = append(handled, line...)
 				line = nil
 			} else if bytes.Contains(line, []byte(prompt)) && !bytes.Contains(line, []byte("PS1=")) {
 				sawPrompt <- true
 				handled = append(handled, line...)
 				line = nil
 			}
 		}
 	}()

 	// Set the bash prompt so that we can see it.
 	if _, err := master.Write([]byte("PS1='" + prompt + "'\n")); err != nil {
 		t.Fatalf("setting prompt: %v", err)
 	}
 	select {
 	case <-sawPrompt:
 	case <-time.After(wait):
 		t.Fatal("timed out waiting for shell prompt")
 	}

 	// Start a small program that reads from stdin
 	// (namely the code at the top of this function).
 	if _, err := master.Write([]byte("GO_TEST_TERMINAL_SIGNALS=1 " + os.Args[0] + " -test.run=TestTerminalSignal\n")); err != nil {
 		t.Fatal(err)
 	}

 	// Wait for the program to print that it is starting.
 	select {
 	case <-progReady:
 	case <-time.After(wait):
 		t.Fatal("timed out waiting for program to start")
 	}

 	// Give the program time to enter the read call.
 	// It doesn't matter much if we occasionally don't wait long enough;
 	// we won't be testing what we want to test, but the overall test
 	// will pass.
 	time.Sleep(pause)

 	// Send a ^Z to stop the program.
 	if _, err := master.Write([]byte{26}); err != nil {
 		t.Fatalf("writing ^Z to pty: %v", err)
 	}

 	// Wait for the program to stop and return to the shell.
 	select {
 	case <-sawPrompt:
 	case <-time.After(wait):
 		t.Fatal("timed out waiting for shell prompt")
 	}

 	// Restart the stopped program.
 	if _, err := master.Write([]byte("fg\n")); err != nil {
 		t.Fatalf("writing %q to pty: %v", "fg", err)
 	}

 	// Give the process time to restart.
 	// This is potentially racy: if the process does not restart
 	// quickly enough then the byte we send will go to bash rather
 	// than the program. Unfortunately there isn't anything we can
 	// look for to know that the program is running again.
 	// bash will print the program name, but that happens before it
 	// restarts the program.
 	time.Sleep(10 * pause)

 	// Write some data for the program to read,
 	// which should cause it to exit.
 	if _, err := master.Write([]byte{'\n'}); err != nil {
 		t.Fatalf("writing %q to pty: %v", "\n", err)
 	}

 	// Wait for the program to exit.
 	select {
 	case <-sawPrompt:
 	case <-time.After(wait):
 		t.Fatal("timed out waiting for shell prompt")
 	}

 	// Exit the shell with the program's exit status.
 	if _, err := master.Write([]byte("exit $?\n")); err != nil {
 		t.Fatalf("writing %q to pty: %v", "exit", err)
 	}

 	if err = cmd.Wait(); err != nil {
 		t.Errorf("subprogram failed: %v", err)
 	}
 }
	// Copyright 2017 The Go Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style
	// license that can be found in the LICENSE file.

	// +build darwin dragonfly freebsd linux,!android netbsd openbsd
	// +build cgo

	// Note that this test does not work on Solaris: issue #22849.
	// Don't run the test on Android because at least some versions of the
	// C library do not define the posix_openpt function.

	package signal_test

	import (
	"bufio"
	"bytes"
	"context"
	"fmt"
	"io"
	"os"
	"os/exec"
	"os/signal/internal/pty"
	"strconv"
	"strings"
	"sync"
	"syscall"
	"testing"
	"time"
	)

	func TestTerminalSignal(t *testing.T) {
	const enteringRead = "test program entering read"
	if os.Getenv("GO_TEST_TERMINAL_SIGNALS") != "" {
	var b [1]byte
	fmt.Println(enteringRead)
	n, err := os.Stdin.Read(b[:])
	if n == 1 {
	if b[0] == '\n' {
	// This is what we expect
	fmt.Println("read newline")
	} else {
	fmt.Printf("read 1 byte: %q\n", b)
	}
	} else {
	fmt.Printf("read %d bytes\n", n)
	}
	if err != nil {
	fmt.Println(err)
	os.Exit(1)
	}
	os.Exit(0)
	}

	t.Parallel()

	// The test requires a shell that uses job control.
	bash, err := exec.LookPath("bash")
	if err != nil {
	t.Skipf("could not find bash: %v", err)
	}

	scale := 1
	if s := os.Getenv("GO_TEST_TIMEOUT_SCALE"); s != "" {
	if sc, err := strconv.Atoi(s); err == nil {
	scale = sc
	}
	}
	pause := time.Duration(scale) * 10 * time.Millisecond
	wait := time.Duration(scale) * 5 * time.Second

	// The test only fails when using a "slow device," in this
	// case a pseudo-terminal.

	master, sname, err := pty.Open()
	if err != nil {
	ptyErr := err.(*pty.PtyError)
	if ptyErr.FuncName == "posix_openpt" && ptyErr.Errno == syscall.EACCES {
	t.Skip("posix_openpt failed with EACCES, assuming chroot and skipping")
	}
	t.Fatal(err)
	}
	defer master.Close()
	slave, err := os.OpenFile(sname, os.O_RDWR, 0)
	if err != nil {
	t.Fatal(err)
	}
	defer slave.Close()

	// Start an interactive shell.
	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancel()
	cmd := exec.CommandContext(ctx, bash, "--norc", "--noprofile", "-i")
	// Clear HISTFILE so that we don't read or clobber the user's bash history.
	cmd.Env = append(os.Environ(), "HISTFILE=")
	cmd.Stdin = slave
	cmd.Stdout = slave
	cmd.Stderr = slave
	cmd.SysProcAttr = &syscall.SysProcAttr{
	Setsid: true,
	Setctty: true,
	Ctty: int(slave.Fd()),
	}

	if err := cmd.Start(); err != nil {
	t.Fatal(err)
	}

	if err := slave.Close(); err != nil {
	t.Errorf("closing slave: %v", err)
	}

	progReady := make(chan bool)
	sawPrompt := make(chan bool, 10)
	const prompt = "prompt> "

	// Read data from master in the background.
	var wg sync.WaitGroup
	wg.Add(1)
	defer wg.Wait()
	go func() {
	defer wg.Done()
	input := bufio.NewReader(master)
	var line, handled []byte
	for {
	b, err := input.ReadByte()
	if err != nil {
	if len(line) > 0 \|\| len(handled) > 0 {
	t.Logf("%q", append(handled, line...))
	}
	if perr, ok := err.(*os.PathError); ok {
	err = perr.Err
	}
	// EOF means master is closed.
	// EIO means child process is done.
	// "file already closed" means deferred close of master has happened.
	if err != io.EOF && err != syscall.EIO && !strings.Contains(err.Error(), "file already closed") {
	t.Logf("error reading from master: %v", err)
	}
	return
	}

	line = append(line, b)

	if b == '\n' {
	t.Logf("%q", append(handled, line...))
	line = nil
	handled = nil
	continue
	}

	if bytes.Contains(line, []byte(enteringRead)) {
	close(progReady)
	handled = append(handled, line...)
	line = nil
	} else if bytes.Contains(line, []byte(prompt)) && !bytes.Contains(line, []byte("PS1=")) {
	sawPrompt <- true
	handled = append(handled, line...)
	line = nil
	}
	}
	}()

	// Set the bash prompt so that we can see it.
	if _, err := master.Write([]byte("PS1='" + prompt + "'\n")); err != nil {
	t.Fatalf("setting prompt: %v", err)
	}
	select {
	case <-sawPrompt:
	case <-time.After(wait):
	t.Fatal("timed out waiting for shell prompt")
	}

	// Start a small program that reads from stdin
	// (namely the code at the top of this function).
	if _, err := master.Write([]byte("GO_TEST_TERMINAL_SIGNALS=1 " + os.Args[0] + " -test.run=TestTerminalSignal\n")); err != nil {
	t.Fatal(err)
	}

	// Wait for the program to print that it is starting.
	select {
	case <-progReady:
	case <-time.After(wait):
	t.Fatal("timed out waiting for program to start")
	}

	// Give the program time to enter the read call.
	// It doesn't matter much if we occasionally don't wait long enough;
	// we won't be testing what we want to test, but the overall test
	// will pass.
	time.Sleep(pause)

	// Send a ^Z to stop the program.
	if _, err := master.Write([]byte{26}); err != nil {
	t.Fatalf("writing ^Z to pty: %v", err)
	}

	// Wait for the program to stop and return to the shell.
	select {
	case <-sawPrompt:
	case <-time.After(wait):
	t.Fatal("timed out waiting for shell prompt")
	}

	// Restart the stopped program.
	if _, err := master.Write([]byte("fg\n")); err != nil {
	t.Fatalf("writing %q to pty: %v", "fg", err)
	}

	// Give the process time to restart.
	// This is potentially racy: if the process does not restart
	// quickly enough then the byte we send will go to bash rather
	// than the program. Unfortunately there isn't anything we can
	// look for to know that the program is running again.
	// bash will print the program name, but that happens before it
	// restarts the program.
	time.Sleep(10 * pause)

	// Write some data for the program to read,
	// which should cause it to exit.
	if _, err := master.Write([]byte{'\n'}); err != nil {
	t.Fatalf("writing %q to pty: %v", "\n", err)
	}

	// Wait for the program to exit.
	select {
	case <-sawPrompt:
	case <-time.After(wait):
	t.Fatal("timed out waiting for shell prompt")
	}

	// Exit the shell with the program's exit status.
	if _, err := master.Write([]byte("exit $?\n")); err != nil {
	t.Fatalf("writing %q to pty: %v", "exit", err)
	}

	if err = cmd.Wait(); err != nil {
	t.Errorf("subprogram failed: %v", err)
	}
	}