one pending read is blocking Run function

internal/therealssh/channel.go

@@ -86,7 +86,7 @@ func (sshCh *SSHChannel) Request(requestType RequestType, payload []byte) ([]byt
 		return nil, fmt.Errorf("request failure: %s", err)
 	}
 
-	data := <-sshCh.msgCh
+	data := <- sshCh.msgCh
 	if data[0] == ResponseFail {
 		return nil, fmt.Errorf("request failure: %s", string(data[1:]))
 	}
@@ -117,8 +117,8 @@ func (sshCh *SSHChannel) Serve() error {
 			err = sshCh.Shell()
 		case RequestExec:
 			err = sshCh.Start(string(data[1:]))
-		//case RequestExecWithoutShell:
-
+		case RequestExecWithoutShell:
+			err = sshCh.Run(string(data[1:]))
 		case RequestWindowChange:
 			cols := binary.BigEndian.Uint32(data[1:])
 			rows := binary.BigEndian.Uint32(data[5:])
@@ -232,6 +232,21 @@ func (sshCh *SSHChannel) Start(command string) error {
 	return sshCh.session.Start(command)
 }
 
+// Run executes provided command on Channel's PTY session and returns output as []byte.
+func (sshCh *SSHChannel) Run(command string) error {
+	if sshCh.session == nil {
+		return errors.New("session is not started")
+	}
+
+	out, err := sshCh.session.Run(command)
+	if err != nil {
+		return err
+	}
+
+	_, err = sshCh.Write(out)
+	return err
+}
+
 func (sshCh *SSHChannel) serveSession() error {
 	defer func() {
 		if err := sshCh.Send(CmdChannelServerClose, nil); err != nil {

internal/therealssh/pty_test.go

@@ -36,7 +36,9 @@ func TestRunInPTY(t *testing.T) {
 
 	server := NewServer(MockAuthorizer{})
 	go func() {
-		require.NoError(t, server.Serve(PipeWithRoutingAddr{acceptConn}))
+		err := server.Serve(PipeWithRoutingAddr{acceptConn})
+		fmt.Println("server.Serve finished with err: ", err)
+		require.NoError(t, err)
 	}()
 
 	_, ch, err := client.OpenChannel(cipher.PubKey{})
@@ -59,9 +61,14 @@ func TestRunInPTY(t *testing.T) {
 	require.NoError(t, err)
 	fmt.Println(res)
 
-	res, err = ch.Request(RequestExec, []byte("ls"))
+	res, err = ch.Request(RequestExecWithoutShell, []byte("ls"))
+	require.NoError(t, err)
+
+	b := make([]byte,6024)
+	_, err = ch.Read(b)
 	require.NoError(t, err)
 	fmt.Println(res)
+	fmt.Println("b: ", b)
 }
 
 type MockAuthorizer struct {}

internal/therealssh/server.go

@@ -41,7 +41,7 @@ const (
 	// RequestExec represents request for new process.
 	RequestExec
 	// RequestExec without shell, for use in integration testing.
-//	RequestExecWithoutShell
+	RequestExecWithoutShell
 	// RequestWindowChange represents request for PTY size change.
 	RequestWindowChange
 )

internal/therealssh/session.go

@@ -1,7 +1,6 @@
 package therealssh
 
 import (
-	"errors"
 	"fmt"
 	"io/ioutil"
 	"os"
@@ -90,19 +89,18 @@ func (s *Session) Run(command string) ([]byte, error) {
 	}
 
 	components := strings.Split(command, " ")
-	cmd := exec.Command(components[0], components[1:]...) // nolint:gosec
-	err = cmd.Run()
+
+	c := exec.Command(components[0],components[1:]...)
+	ptmx, err := pty.Start(c)
 	if err != nil {
 		return nil, err
 	}
-	errP, _ := cmd.StderrPipe()
-	stdErr, _ := ioutil.ReadAll(errP)
-	out, _ := cmd.StdoutPipe()
-	res, _ := ioutil.ReadAll(out)
 
-	if len(stdErr) > 0 {
-		return res, errors.New(string(stdErr))
-	}
+	// Make sure to close the pty at the end.
+	defer func() { _ = ptmx.Close() }() // Best effort.
+
+	// as stated in https://github.com/creack/pty/issues/21#issuecomment-513069505 we can ignore this error
+	res, _ := ioutil.ReadAll(ptmx) // nolint: err
 	return res, nil
 }