restore term when receive signal (#200)

* restore term when receive signal

add `CaptureExitSignal` to capture exit signals and exit gracefull(disabled by default)

* update deps

example/readline-demo/readline-demo.go

@@ -85,6 +85,7 @@ func main() {
 		panic(err)
 	}
 	defer l.Close()
+	l.CaptureExitSignal()
 
 	setPasswordCfg := l.GenPasswordConfig()
 	setPasswordCfg.SetListener(func(line []rune, pos int, key rune) (newLine []rune, newPos int, ok bool) {

go.mod

@@ -3,8 +3,8 @@ module github.com/chzyer/readline
 go 1.15
 
 require (
-	github.com/chzyer/test v0.0.0-20210722231415-061457976a23
+	github.com/chzyer/test v1.0.0
 	golang.org/x/sys v0.0.0-20220310020820-b874c991c1a5
 )
 
-require github.com/chzyer/logex v1.2.0
+require github.com/chzyer/logex v1.2.1

go.sum

@@ -1,6 +1,6 @@
-github.com/chzyer/logex v1.2.0 h1:+eqR0HfOetur4tgnC8ftU5imRnhi4te+BadWS95c5AM=
-github.com/chzyer/logex v1.2.0/go.mod h1:9+9sk7u7pGNWYMkh0hdiL++6OeibzJccyQU4p4MedaY=
-github.com/chzyer/test v0.0.0-20210722231415-061457976a23 h1:dZ0/VyGgQdVGAss6Ju0dt5P0QltE0SFY5Woh6hbIfiQ=
-github.com/chzyer/test v0.0.0-20210722231415-061457976a23/go.mod h1:Q3SI9o4m/ZMnBNeIyt5eFwwo7qiLfzFZmjNmxjkiQlU=
+github.com/chzyer/logex v1.2.1 h1:XHDu3E6q+gdHgsdTPH6ImJMIp436vR6MPtH8gP05QzM=
+github.com/chzyer/logex v1.2.1/go.mod h1:JLbx6lG2kDbNRFnfkgvh4eRJRPX1QCoOIWomwysCBrQ=
+github.com/chzyer/test v1.0.0 h1:p3BQDXSxOhOG0P9z6/hGnII4LGiEPOYBhs8asl/fC04=
+github.com/chzyer/test v1.0.0/go.mod h1:2JlltgoNkt4TW/z9V/IzDdFaMTM2JPIi26O1pF38GC8=
 golang.org/x/sys v0.0.0-20220310020820-b874c991c1a5 h1:y/woIyUBFbpQGKS0u1aHF/40WUDnek3fPOyD08H5Vng=
 golang.org/x/sys v0.0.0-20220310020820-b874c991c1a5/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=

operation.go

@@ -434,6 +434,10 @@ func (o *Operation) Slice() ([]byte, error) {
 }
 
 func (o *Operation) Close() {
+	select {
+	case o.errchan <- io.EOF:
+	default:
+	}
 	o.history.Close()
 }
 

readline.go

@@ -17,7 +17,9 @@
 //
 package readline
 
-import "io"
+import (
+	"io"
+)
 
 type Instance struct {
 	Config    *Config
@@ -270,14 +272,24 @@ func (i *Instance) ReadSlice() ([]byte, error) {
 }
 
 // we must make sure that call Close() before process exit.
+// if there has a pending reading operation, that reading will be interrupted.
+// so you can capture the signal and call Instance.Close(), it's thread-safe.
 func (i *Instance) Close() error {
+	i.Config.Stdin.Close()
+	i.Operation.Close()
 	if err := i.Terminal.Close(); err != nil {
 		return err
 	}
-	i.Config.Stdin.Close()
-	i.Operation.Close()
 	return nil
 }
+
+// call CaptureExitSignal when you want readline exit gracefully.
+func (i *Instance) CaptureExitSignal() {
+	CaptureExitSignal(func() {
+		i.Close()
+	})
+}
+
 func (i *Instance) Clean() {
 	i.Operation.Clean()
 }

utils.go

@@ -6,9 +6,11 @@ import (
 	"container/list"
 	"fmt"
 	"os"
+	"os/signal"
 	"strconv"
 	"strings"
 	"sync"
+	"syscall"
 	"time"
 	"unicode"
 )
@@ -275,3 +277,13 @@ func Debug(o ...interface{}) {
 	fmt.Fprintln(f, o...)
 	f.Close()
 }
+
+func CaptureExitSignal(f func()) {
+	cSignal := make(chan os.Signal, 1)
+	signal.Notify(cSignal, os.Interrupt, syscall.SIGTERM)
+	go func() {
+		for range cSignal {
+			f()
+		}
+	}()
+}