add stdin remapping support

operation.go

@@ -4,7 +4,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"os"
 
 	"golang.org/x/crypto/ssh/terminal"
 )
@@ -330,7 +329,7 @@ func (o *Operation) Password(prompt string) ([]byte, error) {
 	o.t.EnterRawMode()
 	defer o.t.ExitRawMode()
 
-	b, err := terminal.ReadPassword(int(os.Stdin.Fd()))
+	b, err := terminal.ReadPassword(int(o.cfg.Stdin.Fd()))
 	fmt.Fprint(w, "\r\n")
 	return b, err
 }

readline.go

@@ -1,6 +1,9 @@
 package readline
 
-import "io"
+import (
+	"io"
+	"os"
+)
 
 type Instance struct {
 	Config    *Config
@@ -8,6 +11,11 @@ type Instance struct {
 	Operation *Operation
 }
 
+type FdReader interface {
+	io.Reader
+	Fd() uintptr
+}
+
 type Config struct {
 	// prompt supports ANSI escape sequence, so we can color some characters even in windows
 	Prompt string
@@ -30,6 +38,7 @@ type Config struct {
 	InterruptPrompt string
 	EOFPrompt       string
 
+	Stdin  FdReader
 	Stdout io.Writer
 	Stderr io.Writer
 
@@ -46,6 +55,9 @@ func (c *Config) Init() error {
 		return nil
 	}
 	c.inited = true
+	if c.Stdin == nil {
+		c.Stdin = os.Stdin
+	}
 	if c.Stdout == nil {
 		c.Stdout = Stdout
 	}

terminal.go

@@ -36,7 +36,7 @@ func NewTerminal(cfg *Config) (*Terminal, error) {
 }
 
 func (t *Terminal) EnterRawMode() (err error) {
-	t.state, err = MakeRaw(StdinFd)
+	t.state, err = MakeRaw(int(t.cfg.Stdin.Fd()))
 	return err
 }
 
@@ -44,7 +44,7 @@ func (t *Terminal) ExitRawMode() (err error) {
 	if t.state == nil {
 		return
 	}
-	err = Restore(StdinFd, t.state)
+	err = Restore(int(t.cfg.Stdin.Fd()), t.state)
 	if err == nil {
 		t.state = nil
 	}
@@ -91,7 +91,7 @@ func (t *Terminal) ioloop() {
 		expectNextChar bool
 	)
 
-	buf := bufio.NewReader(Stdin)
+	buf := bufio.NewReader(t.cfg.Stdin)
 	for {
 		if !expectNextChar {
 			atomic.StoreInt32(&t.isReading, 0)