Removed direct access to stdio streams in monitor command

Author: cmaglie

cli/feedback/terminal.go

@@ -19,17 +19,38 @@ import (
 	"bufio"
 	"errors"
 	"fmt"
+	"io"
 	"os"
 
 	"golang.org/x/term"
 )
 
+// InteractiveStreams returns the underlying io.Reader and io.Writer to directly stream to
+// stdin and stdout. It errors if the selected output format is not Text or the terminal is
+// not interactive.
+func InteractiveStreams() (io.Reader, io.Writer, error) {
+	if !formatSelected {
+		panic("output format not yet selected")
+	}
+	if format != Text {
+		return nil, nil, errors.New(tr("interactive terminal not supported for the '%s' output format", format))
+	}
+	if !isTerminal() {
+		return nil, nil, errors.New(tr("not running in a terminal"))
+	}
+	return os.Stdin, stdOut, nil
+}
+
+func isTerminal() bool {
+	return term.IsTerminal(int(os.Stdin.Fd()))
+}
+
 // InputUserField prompts the user to input the provided user field.
 func InputUserField(prompt string, secret bool) (string, error) {
 	if format != Text {
 		return "", errors.New(tr("user input not supported for the '%s' output format", format))
 	}
-	if !term.IsTerminal(int(os.Stdin.Fd())) {
+	if !isTerminal() {
 		return "", errors.New(tr("user input not supported in non interactive mode"))
 	}
 

cli/monitor/term.go

@@ -16,24 +16,36 @@
 package monitor
 
 import (
-	"os"
+	"io"
+
+	"github.com/arduino/arduino-cli/cli/feedback"
 )
 
 type stdInOut struct {
+	in  io.Reader
+	out io.Writer
 }
 
 func newStdInOutTerminal() (*stdInOut, error) {
-	return &stdInOut{}, nil
+	in, out, err := feedback.InteractiveStreams()
+	if err != nil {
+		return nil, err
+	}
+
+	return &stdInOut{
+		in:  in,
+		out: out,
+	}, nil
 }
 
 func (n *stdInOut) Close() error {
 	return nil
 }
 
 func (n *stdInOut) Read(buff []byte) (int, error) {
-	return os.Stdin.Read(buff)
+	return n.in.Read(buff)
 }
 
 func (n *stdInOut) Write(buff []byte) (int, error) {
-	return os.Stdout.Write(buff)
+	return n.out.Write(buff)
 }