Merge pull request #684 from Lomanic/issue670

[process][darwin] Fix #670 remove call to common.Pipeline (prone to race condition)

internal/common/common.go

@@ -332,49 +332,6 @@ func HostRun(combineWith ...string) string {
 	return GetEnv("HOST_RUN", "/run", combineWith...)
 }
 
-// https://gist.github.com/kylelemons/1525278
-func Pipeline(cmds ...*exec.Cmd) ([]byte, []byte, error) {
-	// Require at least one command
-	if len(cmds) < 1 {
-		return nil, nil, nil
-	}
-
-	// Collect the output from the command(s)
-	var output bytes.Buffer
-	var stderr bytes.Buffer
-
-	last := len(cmds) - 1
-	for i, cmd := range cmds[:last] {
-		var err error
-		// Connect each command's stdin to the previous command's stdout
-		if cmds[i+1].Stdin, err = cmd.StdoutPipe(); err != nil {
-			return nil, nil, err
-		}
-		// Connect each command's stderr to a buffer
-		cmd.Stderr = &stderr
-	}
-
-	// Connect the output and error for the last command
-	cmds[last].Stdout, cmds[last].Stderr = &output, &stderr
-
-	// Start each command
-	for _, cmd := range cmds {
-		if err := cmd.Start(); err != nil {
-			return output.Bytes(), stderr.Bytes(), err
-		}
-	}
-
-	// Wait for each command to complete
-	for _, cmd := range cmds {
-		if err := cmd.Wait(); err != nil {
-			return output.Bytes(), stderr.Bytes(), err
-		}
-	}
-
-	// Return the pipeline output and the collected standard error
-	return output.Bytes(), stderr.Bytes(), nil
-}
-
 // getSysctrlEnv sets LC_ALL=C in a list of env vars for use when running
 // sysctl commands (see DoSysctrl).
 func getSysctrlEnv(env []string) []string {

internal/common/common_unix.go

@@ -23,7 +23,7 @@ func CallLsofWithContext(ctx context.Context, invoke Invoker, pid int32, args ..
 	}
 	out, err := invoke.CommandWithContext(ctx, lsof, cmd...)
 	if err != nil {
-		// if no pid found, lsof returnes code 1.
+		// if no pid found, lsof returns code 1.
 		if err.Error() == "exit status 1" && len(out) == 0 {
 			return []string{}, nil
 		}

process/process_darwin.go

@@ -108,30 +108,21 @@ func (p *Process) ExeWithContext(ctx context.Context) (string, error) {
 	if err != nil {
 		return "", err
 	}
-
-	awk_bin, err := exec.LookPath("awk")
+	out, err := invoke.CommandWithContext(ctx, lsof_bin, "-p", strconv.Itoa(int(p.Pid)), "-Fpfn")
 	if err != nil {
-		return "", err
+		return "", fmt.Errorf("bad call to lsof: %s", err)
 	}
-
-	sed_bin, err := exec.LookPath("sed")
-	if err != nil {
-		return "", err
-	}
-
-	lsof := exec.CommandContext(ctx, lsof_bin, "-p", strconv.Itoa(int(p.Pid)), "-Fpfn")
-	awk := exec.CommandContext(ctx, awk_bin, "NR==5{print}")
-	sed := exec.CommandContext(ctx, sed_bin, "s/n\\//\\//")
-
-	output, _, err := common.Pipeline(lsof, awk, sed)
-
-	if err != nil {
-		return "", err
+	txtFound := 0
+	lines := strings.Split(string(out), "\n")
+	for i := 1; i < len(lines); i += 2 {
+		if lines[i] == "ftxt" {
+			txtFound++
+			if txtFound == 2 {
+				return lines[i-1][1:], nil
+			}
+		}
 	}
-
-	ret := strings.TrimSpace(string(output))
-
-	return ret, nil
+	return "", fmt.Errorf("missing txt data returned by lsof")
 }
 
 // Cmdline returns the command line arguments of the process as a string with