github.com/dannin/go@v0.0.0-20161031215817-d35dfd405eaa/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 "context" 14 "fmt" 15 "internal/testenv" 16 "io" 17 "io/ioutil" 18 "log" 19 "net" 20 "net/http" 21 "net/http/httptest" 22 "os" 23 "os/exec" 24 "path/filepath" 25 "runtime" 26 "strconv" 27 "strings" 28 "testing" 29 "time" 30 ) 31 32 func helperCommandContext(t *testing.T, ctx context.Context, s ...string) (cmd *exec.Cmd) { 33 testenv.MustHaveExec(t) 34 35 cs := []string{"-test.run=TestHelperProcess", "--"} 36 cs = append(cs, s...) 37 if ctx != nil { 38 cmd = exec.CommandContext(ctx, os.Args[0], cs...) 39 } else { 40 cmd = exec.Command(os.Args[0], cs...) 41 } 42 cmd.Env = []string{"GO_WANT_HELPER_PROCESS=1"} 43 return cmd 44 } 45 46 func helperCommand(t *testing.T, s ...string) *exec.Cmd { 47 return helperCommandContext(t, nil, s...) 48 } 49 50 func TestEcho(t *testing.T) { 51 bs, err := helperCommand(t, "echo", "foo bar", "baz").Output() 52 if err != nil { 53 t.Errorf("echo: %v", err) 54 } 55 if g, e := string(bs), "foo bar baz\n"; g != e { 56 t.Errorf("echo: want %q, got %q", e, g) 57 } 58 } 59 60 func TestCommandRelativeName(t *testing.T) { 61 testenv.MustHaveExec(t) 62 63 // Run our own binary as a relative path 64 // (e.g. "_test/exec.test") our parent directory. 65 base := filepath.Base(os.Args[0]) // "exec.test" 66 dir := filepath.Dir(os.Args[0]) // "/tmp/go-buildNNNN/os/exec/_test" 67 if dir == "." { 68 t.Skip("skipping; running test at root somehow") 69 } 70 parentDir := filepath.Dir(dir) // "/tmp/go-buildNNNN/os/exec" 71 dirBase := filepath.Base(dir) // "_test" 72 if dirBase == "." { 73 t.Skipf("skipping; unexpected shallow dir of %q", dir) 74 } 75 76 cmd := exec.Command(filepath.Join(dirBase, base), "-test.run=TestHelperProcess", "--", "echo", "foo") 77 cmd.Dir = parentDir 78 cmd.Env = []string{"GO_WANT_HELPER_PROCESS=1"} 79 80 out, err := cmd.Output() 81 if err != nil { 82 t.Errorf("echo: %v", err) 83 } 84 if g, e := string(out), "foo\n"; g != e { 85 t.Errorf("echo: want %q, got %q", e, g) 86 } 87 } 88 89 func TestCatStdin(t *testing.T) { 90 // Cat, testing stdin and stdout. 91 input := "Input string\nLine 2" 92 p := helperCommand(t, "cat") 93 p.Stdin = strings.NewReader(input) 94 bs, err := p.Output() 95 if err != nil { 96 t.Errorf("cat: %v", err) 97 } 98 s := string(bs) 99 if s != input { 100 t.Errorf("cat: want %q, got %q", input, s) 101 } 102 } 103 104 func TestEchoFileRace(t *testing.T) { 105 cmd := helperCommand(t, "echo") 106 stdin, err := cmd.StdinPipe() 107 if err != nil { 108 t.Fatalf("StdinPipe: %v", err) 109 } 110 if err := cmd.Start(); err != nil { 111 t.Fatalf("Start: %v", err) 112 } 113 wrote := make(chan bool) 114 go func() { 115 defer close(wrote) 116 fmt.Fprint(stdin, "echo\n") 117 }() 118 if err := cmd.Wait(); err != nil { 119 t.Fatalf("Wait: %v", err) 120 } 121 <-wrote 122 } 123 124 func TestCatGoodAndBadFile(t *testing.T) { 125 // Testing combined output and error values. 126 bs, err := helperCommand(t, "cat", "/bogus/file.foo", "exec_test.go").CombinedOutput() 127 if _, ok := err.(*exec.ExitError); !ok { 128 t.Errorf("expected *exec.ExitError from cat combined; got %T: %v", err, err) 129 } 130 s := string(bs) 131 sp := strings.SplitN(s, "\n", 2) 132 if len(sp) != 2 { 133 t.Fatalf("expected two lines from cat; got %q", s) 134 } 135 errLine, body := sp[0], sp[1] 136 if !strings.HasPrefix(errLine, "Error: open /bogus/file.foo") { 137 t.Errorf("expected stderr to complain about file; got %q", errLine) 138 } 139 if !strings.Contains(body, "func TestHelperProcess(t *testing.T)") { 140 t.Errorf("expected test code; got %q (len %d)", body, len(body)) 141 } 142 } 143 144 func TestNoExistBinary(t *testing.T) { 145 // Can't run a non-existent binary 146 err := exec.Command("/no-exist-binary").Run() 147 if err == nil { 148 t.Error("expected error from /no-exist-binary") 149 } 150 } 151 152 func TestExitStatus(t *testing.T) { 153 // Test that exit values are returned correctly 154 cmd := helperCommand(t, "exit", "42") 155 err := cmd.Run() 156 want := "exit status 42" 157 switch runtime.GOOS { 158 case "plan9": 159 want = fmt.Sprintf("exit status: '%s %d: 42'", filepath.Base(cmd.Path), cmd.ProcessState.Pid()) 160 } 161 if werr, ok := err.(*exec.ExitError); ok { 162 if s := werr.Error(); s != want { 163 t.Errorf("from exit 42 got exit %q, want %q", s, want) 164 } 165 } else { 166 t.Fatalf("expected *exec.ExitError from exit 42; got %T: %v", err, err) 167 } 168 } 169 170 func TestPipes(t *testing.T) { 171 check := func(what string, err error) { 172 if err != nil { 173 t.Fatalf("%s: %v", what, err) 174 } 175 } 176 // Cat, testing stdin and stdout. 177 c := helperCommand(t, "pipetest") 178 stdin, err := c.StdinPipe() 179 check("StdinPipe", err) 180 stdout, err := c.StdoutPipe() 181 check("StdoutPipe", err) 182 stderr, err := c.StderrPipe() 183 check("StderrPipe", err) 184 185 outbr := bufio.NewReader(stdout) 186 errbr := bufio.NewReader(stderr) 187 line := func(what string, br *bufio.Reader) string { 188 line, _, err := br.ReadLine() 189 if err != nil { 190 t.Fatalf("%s: %v", what, err) 191 } 192 return string(line) 193 } 194 195 err = c.Start() 196 check("Start", err) 197 198 _, err = stdin.Write([]byte("O:I am output\n")) 199 check("first stdin Write", err) 200 if g, e := line("first output line", outbr), "O:I am output"; g != e { 201 t.Errorf("got %q, want %q", g, e) 202 } 203 204 _, err = stdin.Write([]byte("E:I am error\n")) 205 check("second stdin Write", err) 206 if g, e := line("first error line", errbr), "E:I am error"; g != e { 207 t.Errorf("got %q, want %q", g, e) 208 } 209 210 _, err = stdin.Write([]byte("O:I am output2\n")) 211 check("third stdin Write 3", err) 212 if g, e := line("second output line", outbr), "O:I am output2"; g != e { 213 t.Errorf("got %q, want %q", g, e) 214 } 215 216 stdin.Close() 217 err = c.Wait() 218 check("Wait", err) 219 } 220 221 const stdinCloseTestString = "Some test string." 222 223 // Issue 6270. 224 func TestStdinClose(t *testing.T) { 225 check := func(what string, err error) { 226 if err != nil { 227 t.Fatalf("%s: %v", what, err) 228 } 229 } 230 cmd := helperCommand(t, "stdinClose") 231 stdin, err := cmd.StdinPipe() 232 check("StdinPipe", err) 233 // Check that we can access methods of the underlying os.File.` 234 if _, ok := stdin.(interface { 235 Fd() uintptr 236 }); !ok { 237 t.Error("can't access methods of underlying *os.File") 238 } 239 check("Start", cmd.Start()) 240 go func() { 241 _, err := io.Copy(stdin, strings.NewReader(stdinCloseTestString)) 242 check("Copy", err) 243 // Before the fix, this next line would race with cmd.Wait. 244 check("Close", stdin.Close()) 245 }() 246 check("Wait", cmd.Wait()) 247 } 248 249 // Issue 5071 250 func TestPipeLookPathLeak(t *testing.T) { 251 fd0, lsof0 := numOpenFDS(t) 252 for i := 0; i < 4; i++ { 253 cmd := exec.Command("something-that-does-not-exist-binary") 254 cmd.StdoutPipe() 255 cmd.StderrPipe() 256 cmd.StdinPipe() 257 if err := cmd.Run(); err == nil { 258 t.Fatal("unexpected success") 259 } 260 } 261 for triesLeft := 3; triesLeft >= 0; triesLeft-- { 262 open, lsof := numOpenFDS(t) 263 fdGrowth := open - fd0 264 if fdGrowth > 2 { 265 if triesLeft > 0 { 266 // Work around what appears to be a race with Linux's 267 // proc filesystem (as used by lsof). It seems to only 268 // be eventually consistent. Give it awhile to settle. 269 // See golang.org/issue/7808 270 time.Sleep(100 * time.Millisecond) 271 continue 272 } 273 t.Errorf("leaked %d fds; want ~0; have:\n%s\noriginally:\n%s", fdGrowth, lsof, lsof0) 274 } 275 break 276 } 277 } 278 279 func numOpenFDS(t *testing.T) (n int, lsof []byte) { 280 if runtime.GOOS == "android" { 281 // Android's stock lsof does not obey the -p option, 282 // so extra filtering is needed. (golang.org/issue/10206) 283 return numOpenFDsAndroid(t) 284 } 285 286 lsof, err := exec.Command("lsof", "-b", "-n", "-p", strconv.Itoa(os.Getpid())).Output() 287 if err != nil { 288 t.Skip("skipping test; error finding or running lsof") 289 } 290 return bytes.Count(lsof, []byte("\n")), lsof 291 } 292 293 func numOpenFDsAndroid(t *testing.T) (n int, lsof []byte) { 294 raw, err := exec.Command("lsof").Output() 295 if err != nil { 296 t.Skip("skipping test; error finding or running lsof") 297 } 298 299 // First find the PID column index by parsing the first line, and 300 // select lines containing pid in the column. 301 pid := []byte(strconv.Itoa(os.Getpid())) 302 pidCol := -1 303 304 s := bufio.NewScanner(bytes.NewReader(raw)) 305 for s.Scan() { 306 line := s.Bytes() 307 fields := bytes.Fields(line) 308 if pidCol < 0 { 309 for i, v := range fields { 310 if bytes.Equal(v, []byte("PID")) { 311 pidCol = i 312 break 313 } 314 } 315 lsof = append(lsof, line...) 316 continue 317 } 318 if bytes.Equal(fields[pidCol], pid) { 319 lsof = append(lsof, '\n') 320 lsof = append(lsof, line...) 321 } 322 } 323 if pidCol < 0 { 324 t.Fatal("error processing lsof output: unexpected header format") 325 } 326 if err := s.Err(); err != nil { 327 t.Fatalf("error processing lsof output: %v", err) 328 } 329 return bytes.Count(lsof, []byte("\n")), lsof 330 } 331 332 var testedAlreadyLeaked = false 333 334 // basefds returns the number of expected file descriptors 335 // to be present in a process at start. 336 func basefds() uintptr { 337 return os.Stderr.Fd() + 1 338 } 339 340 func closeUnexpectedFds(t *testing.T, m string) { 341 for fd := basefds(); fd <= 101; fd++ { 342 err := os.NewFile(fd, "").Close() 343 if err == nil { 344 t.Logf("%s: Something already leaked - closed fd %d", m, fd) 345 } 346 } 347 } 348 349 func TestExtraFilesFDShuffle(t *testing.T) { 350 t.Skip("flaky test; see https://golang.org/issue/5780") 351 switch runtime.GOOS { 352 case "darwin": 353 // TODO(cnicolaou): https://golang.org/issue/2603 354 // leads to leaked file descriptors in this test when it's 355 // run from a builder. 356 closeUnexpectedFds(t, "TestExtraFilesFDShuffle") 357 case "netbsd": 358 // https://golang.org/issue/3955 359 closeUnexpectedFds(t, "TestExtraFilesFDShuffle") 360 case "windows": 361 t.Skip("no operating system support; skipping") 362 } 363 364 // syscall.StartProcess maps all the FDs passed to it in 365 // ProcAttr.Files (the concatenation of stdin,stdout,stderr and 366 // ExtraFiles) into consecutive FDs in the child, that is: 367 // Files{11, 12, 6, 7, 9, 3} should result in the file 368 // represented by FD 11 in the parent being made available as 0 369 // in the child, 12 as 1, etc. 370 // 371 // We want to test that FDs in the child do not get overwritten 372 // by one another as this shuffle occurs. The original implementation 373 // was buggy in that in some data dependent cases it would overwrite 374 // stderr in the child with one of the ExtraFile members. 375 // Testing for this case is difficult because it relies on using 376 // the same FD values as that case. In particular, an FD of 3 377 // must be at an index of 4 or higher in ProcAttr.Files and 378 // the FD of the write end of the Stderr pipe (as obtained by 379 // StderrPipe()) must be the same as the size of ProcAttr.Files; 380 // therefore we test that the read end of this pipe (which is what 381 // is returned to the parent by StderrPipe() being one less than 382 // the size of ProcAttr.Files, i.e. 3+len(cmd.ExtraFiles). 383 // 384 // Moving this test case around within the overall tests may 385 // affect the FDs obtained and hence the checks to catch these cases. 386 npipes := 2 387 c := helperCommand(t, "extraFilesAndPipes", strconv.Itoa(npipes+1)) 388 rd, wr, _ := os.Pipe() 389 defer rd.Close() 390 if rd.Fd() != 3 { 391 t.Errorf("bad test value for test pipe: fd %d", rd.Fd()) 392 } 393 stderr, _ := c.StderrPipe() 394 wr.WriteString("_LAST") 395 wr.Close() 396 397 pipes := make([]struct { 398 r, w *os.File 399 }, npipes) 400 data := []string{"a", "b"} 401 402 for i := 0; i < npipes; i++ { 403 r, w, err := os.Pipe() 404 if err != nil { 405 t.Fatalf("unexpected error creating pipe: %s", err) 406 } 407 pipes[i].r = r 408 pipes[i].w = w 409 w.WriteString(data[i]) 410 c.ExtraFiles = append(c.ExtraFiles, pipes[i].r) 411 defer func() { 412 r.Close() 413 w.Close() 414 }() 415 } 416 // Put fd 3 at the end. 417 c.ExtraFiles = append(c.ExtraFiles, rd) 418 419 stderrFd := int(stderr.(*os.File).Fd()) 420 if stderrFd != ((len(c.ExtraFiles) + 3) - 1) { 421 t.Errorf("bad test value for stderr pipe") 422 } 423 424 expected := "child: " + strings.Join(data, "") + "_LAST" 425 426 err := c.Start() 427 if err != nil { 428 t.Fatalf("Run: %v", err) 429 } 430 ch := make(chan string, 1) 431 go func(ch chan string) { 432 buf := make([]byte, 512) 433 n, err := stderr.Read(buf) 434 if err != nil { 435 t.Fatalf("Read: %s", err) 436 ch <- err.Error() 437 } else { 438 ch <- string(buf[:n]) 439 } 440 close(ch) 441 }(ch) 442 select { 443 case m := <-ch: 444 if m != expected { 445 t.Errorf("Read: '%s' not '%s'", m, expected) 446 } 447 case <-time.After(5 * time.Second): 448 t.Errorf("Read timedout") 449 } 450 c.Wait() 451 } 452 453 func TestExtraFiles(t *testing.T) { 454 testenv.MustHaveExec(t) 455 456 if runtime.GOOS == "windows" { 457 t.Skipf("skipping test on %q", runtime.GOOS) 458 } 459 460 // Ensure that file descriptors have not already been leaked into 461 // our environment. 462 if !testedAlreadyLeaked { 463 testedAlreadyLeaked = true 464 closeUnexpectedFds(t, "TestExtraFiles") 465 } 466 467 // Force network usage, to verify the epoll (or whatever) fd 468 // doesn't leak to the child, 469 ln, err := net.Listen("tcp", "127.0.0.1:0") 470 if err != nil { 471 t.Fatal(err) 472 } 473 defer ln.Close() 474 475 // Make sure duplicated fds don't leak to the child. 476 f, err := ln.(*net.TCPListener).File() 477 if err != nil { 478 t.Fatal(err) 479 } 480 defer f.Close() 481 ln2, err := net.FileListener(f) 482 if err != nil { 483 t.Fatal(err) 484 } 485 defer ln2.Close() 486 487 // Force TLS root certs to be loaded (which might involve 488 // cgo), to make sure none of that potential C code leaks fds. 489 ts := httptest.NewUnstartedServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {})) 490 // quiet expected TLS handshake error "remote error: bad certificate" 491 ts.Config.ErrorLog = log.New(ioutil.Discard, "", 0) 492 ts.StartTLS() 493 defer ts.Close() 494 _, err = http.Get(ts.URL) 495 if err == nil { 496 t.Errorf("success trying to fetch %s; want an error", ts.URL) 497 } 498 499 tf, err := ioutil.TempFile("", "") 500 if err != nil { 501 t.Fatalf("TempFile: %v", err) 502 } 503 defer os.Remove(tf.Name()) 504 defer tf.Close() 505 506 const text = "Hello, fd 3!" 507 _, err = tf.Write([]byte(text)) 508 if err != nil { 509 t.Fatalf("Write: %v", err) 510 } 511 _, err = tf.Seek(0, io.SeekStart) 512 if err != nil { 513 t.Fatalf("Seek: %v", err) 514 } 515 516 c := helperCommand(t, "read3") 517 var stdout, stderr bytes.Buffer 518 c.Stdout = &stdout 519 c.Stderr = &stderr 520 c.ExtraFiles = []*os.File{tf} 521 err = c.Run() 522 if err != nil { 523 t.Fatalf("Run: %v; stdout %q, stderr %q", err, stdout.Bytes(), stderr.Bytes()) 524 } 525 if stdout.String() != text { 526 t.Errorf("got stdout %q, stderr %q; want %q on stdout", stdout.String(), stderr.String(), text) 527 } 528 } 529 530 func TestExtraFilesRace(t *testing.T) { 531 if runtime.GOOS == "windows" { 532 t.Skip("no operating system support; skipping") 533 } 534 listen := func() net.Listener { 535 ln, err := net.Listen("tcp", "127.0.0.1:0") 536 if err != nil { 537 t.Fatal(err) 538 } 539 return ln 540 } 541 listenerFile := func(ln net.Listener) *os.File { 542 f, err := ln.(*net.TCPListener).File() 543 if err != nil { 544 t.Fatal(err) 545 } 546 return f 547 } 548 runCommand := func(c *exec.Cmd, out chan<- string) { 549 bout, err := c.CombinedOutput() 550 if err != nil { 551 out <- "ERROR:" + err.Error() 552 } else { 553 out <- string(bout) 554 } 555 } 556 557 for i := 0; i < 10; i++ { 558 la := listen() 559 ca := helperCommand(t, "describefiles") 560 ca.ExtraFiles = []*os.File{listenerFile(la)} 561 lb := listen() 562 cb := helperCommand(t, "describefiles") 563 cb.ExtraFiles = []*os.File{listenerFile(lb)} 564 ares := make(chan string) 565 bres := make(chan string) 566 go runCommand(ca, ares) 567 go runCommand(cb, bres) 568 if got, want := <-ares, fmt.Sprintf("fd3: listener %s\n", la.Addr()); got != want { 569 t.Errorf("iteration %d, process A got:\n%s\nwant:\n%s\n", i, got, want) 570 } 571 if got, want := <-bres, fmt.Sprintf("fd3: listener %s\n", lb.Addr()); got != want { 572 t.Errorf("iteration %d, process B got:\n%s\nwant:\n%s\n", i, got, want) 573 } 574 la.Close() 575 lb.Close() 576 for _, f := range ca.ExtraFiles { 577 f.Close() 578 } 579 for _, f := range cb.ExtraFiles { 580 f.Close() 581 } 582 583 } 584 } 585 586 // TestHelperProcess isn't a real test. It's used as a helper process 587 // for TestParameterRun. 588 func TestHelperProcess(*testing.T) { 589 if os.Getenv("GO_WANT_HELPER_PROCESS") != "1" { 590 return 591 } 592 defer os.Exit(0) 593 594 // Determine which command to use to display open files. 595 ofcmd := "lsof" 596 switch runtime.GOOS { 597 case "dragonfly", "freebsd", "netbsd", "openbsd": 598 ofcmd = "fstat" 599 case "plan9": 600 ofcmd = "/bin/cat" 601 } 602 603 args := os.Args 604 for len(args) > 0 { 605 if args[0] == "--" { 606 args = args[1:] 607 break 608 } 609 args = args[1:] 610 } 611 if len(args) == 0 { 612 fmt.Fprintf(os.Stderr, "No command\n") 613 os.Exit(2) 614 } 615 616 cmd, args := args[0], args[1:] 617 switch cmd { 618 case "echo": 619 iargs := []interface{}{} 620 for _, s := range args { 621 iargs = append(iargs, s) 622 } 623 fmt.Println(iargs...) 624 case "cat": 625 if len(args) == 0 { 626 io.Copy(os.Stdout, os.Stdin) 627 return 628 } 629 exit := 0 630 for _, fn := range args { 631 f, err := os.Open(fn) 632 if err != nil { 633 fmt.Fprintf(os.Stderr, "Error: %v\n", err) 634 exit = 2 635 } else { 636 defer f.Close() 637 io.Copy(os.Stdout, f) 638 } 639 } 640 os.Exit(exit) 641 case "pipetest": 642 bufr := bufio.NewReader(os.Stdin) 643 for { 644 line, _, err := bufr.ReadLine() 645 if err == io.EOF { 646 break 647 } else if err != nil { 648 os.Exit(1) 649 } 650 if bytes.HasPrefix(line, []byte("O:")) { 651 os.Stdout.Write(line) 652 os.Stdout.Write([]byte{'\n'}) 653 } else if bytes.HasPrefix(line, []byte("E:")) { 654 os.Stderr.Write(line) 655 os.Stderr.Write([]byte{'\n'}) 656 } else { 657 os.Exit(1) 658 } 659 } 660 case "stdinClose": 661 b, err := ioutil.ReadAll(os.Stdin) 662 if err != nil { 663 fmt.Fprintf(os.Stderr, "Error: %v\n", err) 664 os.Exit(1) 665 } 666 if s := string(b); s != stdinCloseTestString { 667 fmt.Fprintf(os.Stderr, "Error: Read %q, want %q", s, stdinCloseTestString) 668 os.Exit(1) 669 } 670 os.Exit(0) 671 case "read3": // read fd 3 672 fd3 := os.NewFile(3, "fd3") 673 bs, err := ioutil.ReadAll(fd3) 674 if err != nil { 675 fmt.Printf("ReadAll from fd 3: %v", err) 676 os.Exit(1) 677 } 678 switch runtime.GOOS { 679 case "dragonfly": 680 // TODO(jsing): Determine why DragonFly is leaking 681 // file descriptors... 682 case "darwin": 683 // TODO(bradfitz): broken? Sometimes. 684 // https://golang.org/issue/2603 685 // Skip this additional part of the test for now. 686 case "netbsd": 687 // TODO(jsing): This currently fails on NetBSD due to 688 // the cloned file descriptors that result from opening 689 // /dev/urandom. 690 // https://golang.org/issue/3955 691 case "solaris": 692 // TODO(aram): This fails on Solaris because libc opens 693 // its own files, as it sees fit. Darwin does the same, 694 // see: https://golang.org/issue/2603 695 default: 696 // Now verify that there are no other open fds. 697 var files []*os.File 698 for wantfd := basefds() + 1; wantfd <= 100; wantfd++ { 699 f, err := os.Open(os.Args[0]) 700 if err != nil { 701 fmt.Printf("error opening file with expected fd %d: %v", wantfd, err) 702 os.Exit(1) 703 } 704 if got := f.Fd(); got != wantfd { 705 fmt.Printf("leaked parent file. fd = %d; want %d\n", got, wantfd) 706 var args []string 707 switch runtime.GOOS { 708 case "plan9": 709 args = []string{fmt.Sprintf("/proc/%d/fd", os.Getpid())} 710 default: 711 args = []string{"-p", fmt.Sprint(os.Getpid())} 712 } 713 out, _ := exec.Command(ofcmd, args...).CombinedOutput() 714 fmt.Print(string(out)) 715 os.Exit(1) 716 } 717 files = append(files, f) 718 } 719 for _, f := range files { 720 f.Close() 721 } 722 } 723 // Referring to fd3 here ensures that it is not 724 // garbage collected, and therefore closed, while 725 // executing the wantfd loop above. It doesn't matter 726 // what we do with fd3 as long as we refer to it; 727 // closing it is the easy choice. 728 fd3.Close() 729 os.Stdout.Write(bs) 730 case "exit": 731 n, _ := strconv.Atoi(args[0]) 732 os.Exit(n) 733 case "describefiles": 734 f := os.NewFile(3, fmt.Sprintf("fd3")) 735 ln, err := net.FileListener(f) 736 if err == nil { 737 fmt.Printf("fd3: listener %s\n", ln.Addr()) 738 ln.Close() 739 } 740 os.Exit(0) 741 case "extraFilesAndPipes": 742 n, _ := strconv.Atoi(args[0]) 743 pipes := make([]*os.File, n) 744 for i := 0; i < n; i++ { 745 pipes[i] = os.NewFile(uintptr(3+i), strconv.Itoa(i)) 746 } 747 response := "" 748 for i, r := range pipes { 749 ch := make(chan string, 1) 750 go func(c chan string) { 751 buf := make([]byte, 10) 752 n, err := r.Read(buf) 753 if err != nil { 754 fmt.Fprintf(os.Stderr, "Child: read error: %v on pipe %d\n", err, i) 755 os.Exit(1) 756 } 757 c <- string(buf[:n]) 758 close(c) 759 }(ch) 760 select { 761 case m := <-ch: 762 response = response + m 763 case <-time.After(5 * time.Second): 764 fmt.Fprintf(os.Stderr, "Child: Timeout reading from pipe: %d\n", i) 765 os.Exit(1) 766 } 767 } 768 fmt.Fprintf(os.Stderr, "child: %s", response) 769 os.Exit(0) 770 case "exec": 771 cmd := exec.Command(args[1]) 772 cmd.Dir = args[0] 773 output, err := cmd.CombinedOutput() 774 if err != nil { 775 fmt.Fprintf(os.Stderr, "Child: %s %s", err, string(output)) 776 os.Exit(1) 777 } 778 fmt.Printf("%s", string(output)) 779 os.Exit(0) 780 case "lookpath": 781 p, err := exec.LookPath(args[0]) 782 if err != nil { 783 fmt.Fprintf(os.Stderr, "LookPath failed: %v\n", err) 784 os.Exit(1) 785 } 786 fmt.Print(p) 787 os.Exit(0) 788 case "stderrfail": 789 fmt.Fprintf(os.Stderr, "some stderr text\n") 790 os.Exit(1) 791 default: 792 fmt.Fprintf(os.Stderr, "Unknown command %q\n", cmd) 793 os.Exit(2) 794 } 795 } 796 797 // Issue 9173: ignore stdin pipe writes if the program completes successfully. 798 func TestIgnorePipeErrorOnSuccess(t *testing.T) { 799 testenv.MustHaveExec(t) 800 801 // We really only care about testing this on Unixy things. 802 if runtime.GOOS == "windows" || runtime.GOOS == "plan9" { 803 t.Skipf("skipping test on %q", runtime.GOOS) 804 } 805 806 cmd := helperCommand(t, "echo", "foo") 807 var out bytes.Buffer 808 cmd.Stdin = strings.NewReader(strings.Repeat("x", 10<<20)) 809 cmd.Stdout = &out 810 if err := cmd.Run(); err != nil { 811 t.Fatal(err) 812 } 813 if got, want := out.String(), "foo\n"; got != want { 814 t.Errorf("output = %q; want %q", got, want) 815 } 816 } 817 818 type badWriter struct{} 819 820 func (w *badWriter) Write(data []byte) (int, error) { 821 return 0, io.ErrUnexpectedEOF 822 } 823 824 func TestClosePipeOnCopyError(t *testing.T) { 825 testenv.MustHaveExec(t) 826 827 if runtime.GOOS == "windows" || runtime.GOOS == "plan9" { 828 t.Skipf("skipping test on %s - no yes command", runtime.GOOS) 829 } 830 cmd := exec.Command("yes") 831 cmd.Stdout = new(badWriter) 832 c := make(chan int, 1) 833 go func() { 834 err := cmd.Run() 835 if err == nil { 836 t.Errorf("yes completed successfully") 837 } 838 c <- 1 839 }() 840 select { 841 case <-c: 842 // ok 843 case <-time.After(5 * time.Second): 844 t.Fatalf("yes got stuck writing to bad writer") 845 } 846 } 847 848 func TestOutputStderrCapture(t *testing.T) { 849 testenv.MustHaveExec(t) 850 851 cmd := helperCommand(t, "stderrfail") 852 _, err := cmd.Output() 853 ee, ok := err.(*exec.ExitError) 854 if !ok { 855 t.Fatalf("Output error type = %T; want ExitError", err) 856 } 857 got := string(ee.Stderr) 858 want := "some stderr text\n" 859 if got != want { 860 t.Errorf("ExitError.Stderr = %q; want %q", got, want) 861 } 862 } 863 864 func TestContext(t *testing.T) { 865 ctx, cancel := context.WithCancel(context.Background()) 866 c := helperCommandContext(t, ctx, "pipetest") 867 stdin, err := c.StdinPipe() 868 if err != nil { 869 t.Fatal(err) 870 } 871 stdout, err := c.StdoutPipe() 872 if err != nil { 873 t.Fatal(err) 874 } 875 if err := c.Start(); err != nil { 876 t.Fatal(err) 877 } 878 879 if _, err := stdin.Write([]byte("O:hi\n")); err != nil { 880 t.Fatal(err) 881 } 882 buf := make([]byte, 5) 883 n, err := io.ReadFull(stdout, buf) 884 if n != len(buf) || err != nil || string(buf) != "O:hi\n" { 885 t.Fatalf("ReadFull = %d, %v, %q", n, err, buf[:n]) 886 } 887 waitErr := make(chan error, 1) 888 go func() { 889 waitErr <- c.Wait() 890 }() 891 cancel() 892 select { 893 case err := <-waitErr: 894 if err == nil { 895 t.Fatal("expected Wait failure") 896 } 897 case <-time.After(3 * time.Second): 898 t.Fatal("timeout waiting for child process death") 899 } 900 } 901 902 func TestContextCancel(t *testing.T) { 903 ctx, cancel := context.WithCancel(context.Background()) 904 defer cancel() 905 c := helperCommandContext(t, ctx, "cat") 906 907 r, w, err := os.Pipe() 908 if err != nil { 909 t.Fatal(err) 910 } 911 c.Stdin = r 912 913 stdout, err := c.StdoutPipe() 914 if err != nil { 915 t.Fatal(err) 916 } 917 readDone := make(chan struct{}) 918 go func() { 919 defer close(readDone) 920 var a [1024]byte 921 for { 922 n, err := stdout.Read(a[:]) 923 if err != nil { 924 if err != io.EOF { 925 t.Errorf("unexpected read error: %v", err) 926 } 927 return 928 } 929 t.Logf("%s", a[:n]) 930 } 931 }() 932 933 if err := c.Start(); err != nil { 934 t.Fatal(err) 935 } 936 937 if err := r.Close(); err != nil { 938 t.Fatal(err) 939 } 940 941 if _, err := io.WriteString(w, "echo"); err != nil { 942 t.Fatal(err) 943 } 944 945 cancel() 946 947 // Calling cancel should have killed the process, so writes 948 // should now fail. Give the process a little while to die. 949 start := time.Now() 950 for { 951 if _, err := io.WriteString(w, "echo"); err != nil { 952 break 953 } 954 if time.Since(start) > time.Second { 955 t.Fatal("cancelling context did not stop program") 956 } 957 time.Sleep(time.Millisecond) 958 } 959 960 if err := w.Close(); err != nil { 961 t.Errorf("error closing write end of pipe: %v", err) 962 } 963 <-readDone 964 965 if err := c.Wait(); err == nil { 966 t.Error("program unexpectedly exited successfully") 967 } else { 968 t.Logf("exit status: %v", err) 969 } 970 }