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// 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"
"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.
go func() {
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)
}
}