github.com/golang-haiku/go-1.4.3@v0.0.0-20190609233734-1f5ae41cc308/src/os/exec/exec_test.go (about)

     1  // Copyright 2009 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // Use an external test to avoid os/exec -> net/http -> crypto/x509 -> os/exec
     6  // circular dependency on non-cgo darwin.
     7  
     8  package exec_test
     9  
    10  import (
    11  	"bufio"
    12  	"bytes"
    13  	"fmt"
    14  	"io"
    15  	"io/ioutil"
    16  	"log"
    17  	"net"
    18  	"net/http"
    19  	"net/http/httptest"
    20  	"os"
    21  	"os/exec"
    22  	"path/filepath"
    23  	"runtime"
    24  	"strconv"
    25  	"strings"
    26  	"testing"
    27  	"time"
    28  )
    29  
    30  func helperCommand(t *testing.T, s ...string) *exec.Cmd {
    31  	if runtime.GOOS == "nacl" {
    32  		t.Skip("skipping on nacl")
    33  	}
    34  	cs := []string{"-test.run=TestHelperProcess", "--"}
    35  	cs = append(cs, s...)
    36  	cmd := exec.Command(os.Args[0], cs...)
    37  	cmd.Env = []string{"GO_WANT_HELPER_PROCESS=1"}
    38  	return cmd
    39  }
    40  
    41  func TestEcho(t *testing.T) {
    42  	bs, err := helperCommand(t, "echo", "foo bar", "baz").Output()
    43  	if err != nil {
    44  		t.Errorf("echo: %v", err)
    45  	}
    46  	if g, e := string(bs), "foo bar baz\n"; g != e {
    47  		t.Errorf("echo: want %q, got %q", e, g)
    48  	}
    49  }
    50  
    51  func TestCommandRelativeName(t *testing.T) {
    52  	// Run our own binary as a relative path
    53  	// (e.g. "_test/exec.test") our parent directory.
    54  	base := filepath.Base(os.Args[0]) // "exec.test"
    55  	dir := filepath.Dir(os.Args[0])   // "/tmp/go-buildNNNN/os/exec/_test"
    56  	if dir == "." {
    57  		t.Skip("skipping; running test at root somehow")
    58  	}
    59  	parentDir := filepath.Dir(dir) // "/tmp/go-buildNNNN/os/exec"
    60  	dirBase := filepath.Base(dir)  // "_test"
    61  	if dirBase == "." {
    62  		t.Skipf("skipping; unexpected shallow dir of %q", dir)
    63  	}
    64  
    65  	cmd := exec.Command(filepath.Join(dirBase, base), "-test.run=TestHelperProcess", "--", "echo", "foo")
    66  	cmd.Dir = parentDir
    67  	cmd.Env = []string{"GO_WANT_HELPER_PROCESS=1"}
    68  
    69  	out, err := cmd.Output()
    70  	if err != nil {
    71  		t.Errorf("echo: %v", err)
    72  	}
    73  	if g, e := string(out), "foo\n"; g != e {
    74  		t.Errorf("echo: want %q, got %q", e, g)
    75  	}
    76  }
    77  
    78  func TestCatStdin(t *testing.T) {
    79  	if runtime.GOOS == "haiku" {
    80  		t.Skip("skipping on haiku")
    81  	}
    82  	// Cat, testing stdin and stdout.
    83  	input := "Input string\nLine 2"
    84  	p := helperCommand(t, "cat")
    85  	p.Stdin = strings.NewReader(input)
    86  	bs, err := p.Output()
    87  	if err != nil {
    88  		t.Errorf("cat: %v", err)
    89  	}
    90  	s := string(bs)
    91  	if s != input {
    92  		t.Errorf("cat: want %q, got %q", input, s)
    93  	}
    94  }
    95  
    96  func TestCatGoodAndBadFile(t *testing.T) {
    97  	// Testing combined output and error values.
    98  	bs, err := helperCommand(t, "cat", "/bogus/file.foo", "exec_test.go").CombinedOutput()
    99  	if _, ok := err.(*exec.ExitError); !ok {
   100  		t.Errorf("expected *exec.ExitError from cat combined; got %T: %v", err, err)
   101  	}
   102  	s := string(bs)
   103  	sp := strings.SplitN(s, "\n", 2)
   104  	if len(sp) != 2 {
   105  		t.Fatalf("expected two lines from cat; got %q", s)
   106  	}
   107  	errLine, body := sp[0], sp[1]
   108  	if !strings.HasPrefix(errLine, "Error: open /bogus/file.foo") {
   109  		t.Errorf("expected stderr to complain about file; got %q", errLine)
   110  	}
   111  	if !strings.Contains(body, "func TestHelperProcess(t *testing.T)") {
   112  		t.Errorf("expected test code; got %q (len %d)", body, len(body))
   113  	}
   114  }
   115  
   116  func TestNoExistBinary(t *testing.T) {
   117  	// Can't run a non-existent binary
   118  	err := exec.Command("/no-exist-binary").Run()
   119  	if err == nil {
   120  		t.Error("expected error from /no-exist-binary")
   121  	}
   122  }
   123  
   124  func TestExitStatus(t *testing.T) {
   125  	// Test that exit values are returned correctly
   126  	cmd := helperCommand(t, "exit", "42")
   127  	err := cmd.Run()
   128  	want := "exit status 42"
   129  	switch runtime.GOOS {
   130  	case "plan9":
   131  		want = fmt.Sprintf("exit status: '%s %d: 42'", filepath.Base(cmd.Path), cmd.ProcessState.Pid())
   132  	}
   133  	if werr, ok := err.(*exec.ExitError); ok {
   134  		if s := werr.Error(); s != want {
   135  			t.Errorf("from exit 42 got exit %q, want %q", s, want)
   136  		}
   137  	} else {
   138  		t.Fatalf("expected *exec.ExitError from exit 42; got %T: %v", err, err)
   139  	}
   140  }
   141  
   142  func TestPipes(t *testing.T) {
   143  	check := func(what string, err error) {
   144  		if err != nil {
   145  			t.Fatalf("%s: %v", what, err)
   146  		}
   147  	}
   148  	// Cat, testing stdin and stdout.
   149  	c := helperCommand(t, "pipetest")
   150  	stdin, err := c.StdinPipe()
   151  	check("StdinPipe", err)
   152  	stdout, err := c.StdoutPipe()
   153  	check("StdoutPipe", err)
   154  	stderr, err := c.StderrPipe()
   155  	check("StderrPipe", err)
   156  
   157  	outbr := bufio.NewReader(stdout)
   158  	errbr := bufio.NewReader(stderr)
   159  	line := func(what string, br *bufio.Reader) string {
   160  		line, _, err := br.ReadLine()
   161  		if err != nil {
   162  			t.Fatalf("%s: %v", what, err)
   163  		}
   164  		return string(line)
   165  	}
   166  
   167  	err = c.Start()
   168  	check("Start", err)
   169  
   170  	_, err = stdin.Write([]byte("O:I am output\n"))
   171  	check("first stdin Write", err)
   172  	if g, e := line("first output line", outbr), "O:I am output"; g != e {
   173  		t.Errorf("got %q, want %q", g, e)
   174  	}
   175  
   176  	_, err = stdin.Write([]byte("E:I am error\n"))
   177  	check("second stdin Write", err)
   178  	if g, e := line("first error line", errbr), "E:I am error"; g != e {
   179  		t.Errorf("got %q, want %q", g, e)
   180  	}
   181  
   182  	_, err = stdin.Write([]byte("O:I am output2\n"))
   183  	check("third stdin Write 3", err)
   184  	if g, e := line("second output line", outbr), "O:I am output2"; g != e {
   185  		t.Errorf("got %q, want %q", g, e)
   186  	}
   187  
   188  	stdin.Close()
   189  	err = c.Wait()
   190  	check("Wait", err)
   191  }
   192  
   193  const stdinCloseTestString = "Some test string."
   194  
   195  // Issue 6270.
   196  func TestStdinClose(t *testing.T) {
   197  	check := func(what string, err error) {
   198  		if err != nil {
   199  			t.Fatalf("%s: %v", what, err)
   200  		}
   201  	}
   202  	cmd := helperCommand(t, "stdinClose")
   203  	stdin, err := cmd.StdinPipe()
   204  	check("StdinPipe", err)
   205  	// Check that we can access methods of the underlying os.File.`
   206  	if _, ok := stdin.(interface {
   207  		Fd() uintptr
   208  	}); !ok {
   209  		t.Error("can't access methods of underlying *os.File")
   210  	}
   211  	check("Start", cmd.Start())
   212  	go func() {
   213  		_, err := io.Copy(stdin, strings.NewReader(stdinCloseTestString))
   214  		check("Copy", err)
   215  		// Before the fix, this next line would race with cmd.Wait.
   216  		check("Close", stdin.Close())
   217  	}()
   218  	check("Wait", cmd.Wait())
   219  }
   220  
   221  // Issue 5071
   222  func TestPipeLookPathLeak(t *testing.T) {
   223  	fd0, lsof0 := numOpenFDS(t)
   224  	for i := 0; i < 4; i++ {
   225  		cmd := exec.Command("something-that-does-not-exist-binary")
   226  		cmd.StdoutPipe()
   227  		cmd.StderrPipe()
   228  		cmd.StdinPipe()
   229  		if err := cmd.Run(); err == nil {
   230  			t.Fatal("unexpected success")
   231  		}
   232  	}
   233  	for triesLeft := 3; triesLeft >= 0; triesLeft-- {
   234  		open, lsof := numOpenFDS(t)
   235  		fdGrowth := open - fd0
   236  		if fdGrowth > 2 {
   237  			if triesLeft > 0 {
   238  				// Work around what appears to be a race with Linux's
   239  				// proc filesystem (as used by lsof). It seems to only
   240  				// be eventually consistent. Give it awhile to settle.
   241  				// See golang.org/issue/7808
   242  				time.Sleep(100 * time.Millisecond)
   243  				continue
   244  			}
   245  			t.Errorf("leaked %d fds; want ~0; have:\n%s\noriginally:\n%s", fdGrowth, lsof, lsof0)
   246  		}
   247  		break
   248  	}
   249  }
   250  
   251  func numOpenFDS(t *testing.T) (n int, lsof []byte) {
   252  	lsof, err := exec.Command("lsof", "-b", "-n", "-p", strconv.Itoa(os.Getpid())).Output()
   253  	if err != nil {
   254  		t.Skip("skipping test; error finding or running lsof")
   255  	}
   256  	return bytes.Count(lsof, []byte("\n")), lsof
   257  }
   258  
   259  var testedAlreadyLeaked = false
   260  
   261  // basefds returns the number of expected file descriptors
   262  // to be present in a process at start.
   263  func basefds() uintptr {
   264  	return os.Stderr.Fd() + 1
   265  }
   266  
   267  func closeUnexpectedFds(t *testing.T, m string) {
   268  	for fd := basefds(); fd <= 101; fd++ {
   269  		err := os.NewFile(fd, "").Close()
   270  		if err == nil {
   271  			t.Logf("%s: Something already leaked - closed fd %d", m, fd)
   272  		}
   273  	}
   274  }
   275  
   276  func TestExtraFilesFDShuffle(t *testing.T) {
   277  	t.Skip("flaky test; see http://golang.org/issue/5780")
   278  	switch runtime.GOOS {
   279  	case "darwin":
   280  		// TODO(cnicolaou): http://golang.org/issue/2603
   281  		// leads to leaked file descriptors in this test when it's
   282  		// run from a builder.
   283  		closeUnexpectedFds(t, "TestExtraFilesFDShuffle")
   284  	case "netbsd":
   285  		// http://golang.org/issue/3955
   286  		closeUnexpectedFds(t, "TestExtraFilesFDShuffle")
   287  	case "windows":
   288  		t.Skip("no operating system support; skipping")
   289  	}
   290  
   291  	// syscall.StartProcess maps all the FDs passed to it in
   292  	// ProcAttr.Files (the concatenation of stdin,stdout,stderr and
   293  	// ExtraFiles) into consecutive FDs in the child, that is:
   294  	// Files{11, 12, 6, 7, 9, 3} should result in the file
   295  	// represented by FD 11 in the parent being made available as 0
   296  	// in the child, 12 as 1, etc.
   297  	//
   298  	// We want to test that FDs in the child do not get overwritten
   299  	// by one another as this shuffle occurs. The original implementation
   300  	// was buggy in that in some data dependent cases it would ovewrite
   301  	// stderr in the child with one of the ExtraFile members.
   302  	// Testing for this case is difficult because it relies on using
   303  	// the same FD values as that case. In particular, an FD of 3
   304  	// must be at an index of 4 or higher in ProcAttr.Files and
   305  	// the FD of the write end of the Stderr pipe (as obtained by
   306  	// StderrPipe()) must be the same as the size of ProcAttr.Files;
   307  	// therefore we test that the read end of this pipe (which is what
   308  	// is returned to the parent by StderrPipe() being one less than
   309  	// the size of ProcAttr.Files, i.e. 3+len(cmd.ExtraFiles).
   310  	//
   311  	// Moving this test case around within the overall tests may
   312  	// affect the FDs obtained and hence the checks to catch these cases.
   313  	npipes := 2
   314  	c := helperCommand(t, "extraFilesAndPipes", strconv.Itoa(npipes+1))
   315  	rd, wr, _ := os.Pipe()
   316  	defer rd.Close()
   317  	if rd.Fd() != 3 {
   318  		t.Errorf("bad test value for test pipe: fd %d", rd.Fd())
   319  	}
   320  	stderr, _ := c.StderrPipe()
   321  	wr.WriteString("_LAST")
   322  	wr.Close()
   323  
   324  	pipes := make([]struct {
   325  		r, w *os.File
   326  	}, npipes)
   327  	data := []string{"a", "b"}
   328  
   329  	for i := 0; i < npipes; i++ {
   330  		r, w, err := os.Pipe()
   331  		if err != nil {
   332  			t.Fatalf("unexpected error creating pipe: %s", err)
   333  		}
   334  		pipes[i].r = r
   335  		pipes[i].w = w
   336  		w.WriteString(data[i])
   337  		c.ExtraFiles = append(c.ExtraFiles, pipes[i].r)
   338  		defer func() {
   339  			r.Close()
   340  			w.Close()
   341  		}()
   342  	}
   343  	// Put fd 3 at the end.
   344  	c.ExtraFiles = append(c.ExtraFiles, rd)
   345  
   346  	stderrFd := int(stderr.(*os.File).Fd())
   347  	if stderrFd != ((len(c.ExtraFiles) + 3) - 1) {
   348  		t.Errorf("bad test value for stderr pipe")
   349  	}
   350  
   351  	expected := "child: " + strings.Join(data, "") + "_LAST"
   352  
   353  	err := c.Start()
   354  	if err != nil {
   355  		t.Fatalf("Run: %v", err)
   356  	}
   357  	ch := make(chan string, 1)
   358  	go func(ch chan string) {
   359  		buf := make([]byte, 512)
   360  		n, err := stderr.Read(buf)
   361  		if err != nil {
   362  			t.Fatalf("Read: %s", err)
   363  			ch <- err.Error()
   364  		} else {
   365  			ch <- string(buf[:n])
   366  		}
   367  		close(ch)
   368  	}(ch)
   369  	select {
   370  	case m := <-ch:
   371  		if m != expected {
   372  			t.Errorf("Read: '%s' not '%s'", m, expected)
   373  		}
   374  	case <-time.After(5 * time.Second):
   375  		t.Errorf("Read timedout")
   376  	}
   377  	c.Wait()
   378  }
   379  
   380  func TestExtraFiles(t *testing.T) {
   381  	switch runtime.GOOS {
   382  	case "nacl", "windows":
   383  		t.Skipf("skipping test on %q", runtime.GOOS)
   384  	}
   385  
   386  	// Ensure that file descriptors have not already been leaked into
   387  	// our environment.
   388  	if !testedAlreadyLeaked {
   389  		testedAlreadyLeaked = true
   390  		closeUnexpectedFds(t, "TestExtraFiles")
   391  	}
   392  
   393  	// Force network usage, to verify the epoll (or whatever) fd
   394  	// doesn't leak to the child,
   395  	ln, err := net.Listen("tcp", "127.0.0.1:0")
   396  	if err != nil {
   397  		t.Fatal(err)
   398  	}
   399  	defer ln.Close()
   400  
   401  	// Make sure duplicated fds don't leak to the child.
   402  	f, err := ln.(*net.TCPListener).File()
   403  	if err != nil {
   404  		t.Fatal(err)
   405  	}
   406  	defer f.Close()
   407  	ln2, err := net.FileListener(f)
   408  	if err != nil {
   409  		t.Fatal(err)
   410  	}
   411  	defer ln2.Close()
   412  
   413  	// Force TLS root certs to be loaded (which might involve
   414  	// cgo), to make sure none of that potential C code leaks fds.
   415  	ts := httptest.NewUnstartedServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {}))
   416  	// quiet expected TLS handshake error "remote error: bad certificate"
   417  	ts.Config.ErrorLog = log.New(ioutil.Discard, "", 0)
   418  	ts.StartTLS()
   419  	defer ts.Close()
   420  	_, err = http.Get(ts.URL)
   421  	if err == nil {
   422  		t.Errorf("success trying to fetch %s; want an error", ts.URL)
   423  	}
   424  
   425  	tf, err := ioutil.TempFile("", "")
   426  	if err != nil {
   427  		t.Fatalf("TempFile: %v", err)
   428  	}
   429  	defer os.Remove(tf.Name())
   430  	defer tf.Close()
   431  
   432  	const text = "Hello, fd 3!"
   433  	_, err = tf.Write([]byte(text))
   434  	if err != nil {
   435  		t.Fatalf("Write: %v", err)
   436  	}
   437  	_, err = tf.Seek(0, os.SEEK_SET)
   438  	if err != nil {
   439  		t.Fatalf("Seek: %v", err)
   440  	}
   441  
   442  	c := helperCommand(t, "read3")
   443  	var stdout, stderr bytes.Buffer
   444  	c.Stdout = &stdout
   445  	c.Stderr = &stderr
   446  	c.ExtraFiles = []*os.File{tf}
   447  	err = c.Run()
   448  	if err != nil {
   449  		t.Fatalf("Run: %v; stdout %q, stderr %q", err, stdout.Bytes(), stderr.Bytes())
   450  	}
   451  	if stdout.String() != text {
   452  		t.Errorf("got stdout %q, stderr %q; want %q on stdout", stdout.String(), stderr.String(), text)
   453  	}
   454  }
   455  
   456  func TestExtraFilesRace(t *testing.T) {
   457  	if runtime.GOOS == "windows" {
   458  		t.Skip("no operating system support; skipping")
   459  	}
   460  	listen := func() net.Listener {
   461  		ln, err := net.Listen("tcp", "127.0.0.1:0")
   462  		if err != nil {
   463  			t.Fatal(err)
   464  		}
   465  		return ln
   466  	}
   467  	listenerFile := func(ln net.Listener) *os.File {
   468  		f, err := ln.(*net.TCPListener).File()
   469  		if err != nil {
   470  			t.Fatal(err)
   471  		}
   472  		return f
   473  	}
   474  	runCommand := func(c *exec.Cmd, out chan<- string) {
   475  		bout, err := c.CombinedOutput()
   476  		if err != nil {
   477  			out <- "ERROR:" + err.Error()
   478  		} else {
   479  			out <- string(bout)
   480  		}
   481  	}
   482  
   483  	for i := 0; i < 10; i++ {
   484  		la := listen()
   485  		ca := helperCommand(t, "describefiles")
   486  		ca.ExtraFiles = []*os.File{listenerFile(la)}
   487  		lb := listen()
   488  		cb := helperCommand(t, "describefiles")
   489  		cb.ExtraFiles = []*os.File{listenerFile(lb)}
   490  		ares := make(chan string)
   491  		bres := make(chan string)
   492  		go runCommand(ca, ares)
   493  		go runCommand(cb, bres)
   494  		if got, want := <-ares, fmt.Sprintf("fd3: listener %s\n", la.Addr()); got != want {
   495  			t.Errorf("iteration %d, process A got:\n%s\nwant:\n%s\n", i, got, want)
   496  		}
   497  		if got, want := <-bres, fmt.Sprintf("fd3: listener %s\n", lb.Addr()); got != want {
   498  			t.Errorf("iteration %d, process B got:\n%s\nwant:\n%s\n", i, got, want)
   499  		}
   500  		la.Close()
   501  		lb.Close()
   502  		for _, f := range ca.ExtraFiles {
   503  			f.Close()
   504  		}
   505  		for _, f := range cb.ExtraFiles {
   506  			f.Close()
   507  		}
   508  
   509  	}
   510  }
   511  
   512  // TestHelperProcess isn't a real test. It's used as a helper process
   513  // for TestParameterRun.
   514  func TestHelperProcess(*testing.T) {
   515  	if os.Getenv("GO_WANT_HELPER_PROCESS") != "1" {
   516  		return
   517  	}
   518  	defer os.Exit(0)
   519  
   520  	// Determine which command to use to display open files.
   521  	ofcmd := "lsof"
   522  	switch runtime.GOOS {
   523  	case "dragonfly", "freebsd", "netbsd", "openbsd":
   524  		ofcmd = "fstat"
   525  	case "plan9":
   526  		ofcmd = "/bin/cat"
   527  	}
   528  
   529  	args := os.Args
   530  	for len(args) > 0 {
   531  		if args[0] == "--" {
   532  			args = args[1:]
   533  			break
   534  		}
   535  		args = args[1:]
   536  	}
   537  	if len(args) == 0 {
   538  		fmt.Fprintf(os.Stderr, "No command\n")
   539  		os.Exit(2)
   540  	}
   541  
   542  	cmd, args := args[0], args[1:]
   543  	switch cmd {
   544  	case "echo":
   545  		iargs := []interface{}{}
   546  		for _, s := range args {
   547  			iargs = append(iargs, s)
   548  		}
   549  		fmt.Println(iargs...)
   550  	case "cat":
   551  		if len(args) == 0 {
   552  			io.Copy(os.Stdout, os.Stdin)
   553  			return
   554  		}
   555  		exit := 0
   556  		for _, fn := range args {
   557  			f, err := os.Open(fn)
   558  			if err != nil {
   559  				fmt.Fprintf(os.Stderr, "Error: %v\n", err)
   560  				exit = 2
   561  			} else {
   562  				defer f.Close()
   563  				io.Copy(os.Stdout, f)
   564  			}
   565  		}
   566  		os.Exit(exit)
   567  	case "pipetest":
   568  		bufr := bufio.NewReader(os.Stdin)
   569  		for {
   570  			line, _, err := bufr.ReadLine()
   571  			if err == io.EOF {
   572  				break
   573  			} else if err != nil {
   574  				os.Exit(1)
   575  			}
   576  			if bytes.HasPrefix(line, []byte("O:")) {
   577  				os.Stdout.Write(line)
   578  				os.Stdout.Write([]byte{'\n'})
   579  			} else if bytes.HasPrefix(line, []byte("E:")) {
   580  				os.Stderr.Write(line)
   581  				os.Stderr.Write([]byte{'\n'})
   582  			} else {
   583  				os.Exit(1)
   584  			}
   585  		}
   586  	case "stdinClose":
   587  		b, err := ioutil.ReadAll(os.Stdin)
   588  		if err != nil {
   589  			fmt.Fprintf(os.Stderr, "Error: %v\n", err)
   590  			os.Exit(1)
   591  		}
   592  		if s := string(b); s != stdinCloseTestString {
   593  			fmt.Fprintf(os.Stderr, "Error: Read %q, want %q", s, stdinCloseTestString)
   594  			os.Exit(1)
   595  		}
   596  		os.Exit(0)
   597  	case "read3": // read fd 3
   598  		fd3 := os.NewFile(3, "fd3")
   599  		bs, err := ioutil.ReadAll(fd3)
   600  		if err != nil {
   601  			fmt.Printf("ReadAll from fd 3: %v", err)
   602  			os.Exit(1)
   603  		}
   604  		switch runtime.GOOS {
   605  		case "dragonfly":
   606  			// TODO(jsing): Determine why DragonFly is leaking
   607  			// file descriptors...
   608  		case "darwin":
   609  			// TODO(bradfitz): broken? Sometimes.
   610  			// http://golang.org/issue/2603
   611  			// Skip this additional part of the test for now.
   612  		case "netbsd":
   613  			// TODO(jsing): This currently fails on NetBSD due to
   614  			// the cloned file descriptors that result from opening
   615  			// /dev/urandom.
   616  			// http://golang.org/issue/3955
   617  		case "plan9":
   618  			// TODO(0intro): Determine why Plan 9 is leaking
   619  			// file descriptors.
   620  			// http://golang.org/issue/7118
   621  		case "solaris":
   622  			// TODO(aram): This fails on Solaris because libc opens
   623  			// its own files, as it sees fit. Darwin does the same,
   624  			// see: http://golang.org/issue/2603
   625  		default:
   626  			// Now verify that there are no other open fds.
   627  			var files []*os.File
   628  			for wantfd := basefds() + 1; wantfd <= 100; wantfd++ {
   629  				f, err := os.Open(os.Args[0])
   630  				if err != nil {
   631  					fmt.Printf("error opening file with expected fd %d: %v", wantfd, err)
   632  					os.Exit(1)
   633  				}
   634  				if got := f.Fd(); got != wantfd {
   635  					fmt.Printf("leaked parent file. fd = %d; want %d\n", got, wantfd)
   636  					var args []string
   637  					switch runtime.GOOS {
   638  					case "plan9":
   639  						args = []string{fmt.Sprintf("/proc/%d/fd", os.Getpid())}
   640  					default:
   641  						args = []string{"-p", fmt.Sprint(os.Getpid())}
   642  					}
   643  					out, _ := exec.Command(ofcmd, args...).CombinedOutput()
   644  					fmt.Print(string(out))
   645  					os.Exit(1)
   646  				}
   647  				files = append(files, f)
   648  			}
   649  			for _, f := range files {
   650  				f.Close()
   651  			}
   652  		}
   653  		// Referring to fd3 here ensures that it is not
   654  		// garbage collected, and therefore closed, while
   655  		// executing the wantfd loop above.  It doesn't matter
   656  		// what we do with fd3 as long as we refer to it;
   657  		// closing it is the easy choice.
   658  		fd3.Close()
   659  		os.Stdout.Write(bs)
   660  	case "exit":
   661  		n, _ := strconv.Atoi(args[0])
   662  		os.Exit(n)
   663  	case "describefiles":
   664  		f := os.NewFile(3, fmt.Sprintf("fd3"))
   665  		ln, err := net.FileListener(f)
   666  		if err == nil {
   667  			fmt.Printf("fd3: listener %s\n", ln.Addr())
   668  			ln.Close()
   669  		}
   670  		os.Exit(0)
   671  	case "extraFilesAndPipes":
   672  		n, _ := strconv.Atoi(args[0])
   673  		pipes := make([]*os.File, n)
   674  		for i := 0; i < n; i++ {
   675  			pipes[i] = os.NewFile(uintptr(3+i), strconv.Itoa(i))
   676  		}
   677  		response := ""
   678  		for i, r := range pipes {
   679  			ch := make(chan string, 1)
   680  			go func(c chan string) {
   681  				buf := make([]byte, 10)
   682  				n, err := r.Read(buf)
   683  				if err != nil {
   684  					fmt.Fprintf(os.Stderr, "Child: read error: %v on pipe %d\n", err, i)
   685  					os.Exit(1)
   686  				}
   687  				c <- string(buf[:n])
   688  				close(c)
   689  			}(ch)
   690  			select {
   691  			case m := <-ch:
   692  				response = response + m
   693  			case <-time.After(5 * time.Second):
   694  				fmt.Fprintf(os.Stderr, "Child: Timeout reading from pipe: %d\n", i)
   695  				os.Exit(1)
   696  			}
   697  		}
   698  		fmt.Fprintf(os.Stderr, "child: %s", response)
   699  		os.Exit(0)
   700  	case "exec":
   701  		cmd := exec.Command(args[1])
   702  		cmd.Dir = args[0]
   703  		output, err := cmd.CombinedOutput()
   704  		if err != nil {
   705  			fmt.Fprintf(os.Stderr, "Child: %s %s", err, string(output))
   706  			os.Exit(1)
   707  		}
   708  		fmt.Printf("%s", string(output))
   709  		os.Exit(0)
   710  	case "lookpath":
   711  		p, err := exec.LookPath(args[0])
   712  		if err != nil {
   713  			fmt.Fprintf(os.Stderr, "LookPath failed: %v\n", err)
   714  			os.Exit(1)
   715  		}
   716  		fmt.Print(p)
   717  		os.Exit(0)
   718  	default:
   719  		fmt.Fprintf(os.Stderr, "Unknown command %q\n", cmd)
   720  		os.Exit(2)
   721  	}
   722  }