diff --git a/goblin.go b/goblin.go
index 608f540..d022f8a 100644
--- a/goblin.go
+++ b/goblin.go
@@ -12,6 +12,7 @@ import(
 	"github.com/jienfak/goblin/sort"
 	"github.com/jienfak/goblin/tac"
 	"github.com/jienfak/goblin/ls"
+	"github.com/jienfak/goblin/yes"
 )
 
 func main() {
@@ -30,6 +31,7 @@ func main() {
 		"sort" : sort.Run,
 		"tac" : tac.Run,
 		"ls" : ls.Run,
+		"yes" : yes.Run,
 	}
 
 	if binBase := path.Base(os.Args[0]) ; binBase != "goblin" {
diff --git a/sort/sort.go b/sort/sort.go
index 7cd8b26..02f5b76 100644
--- a/sort/sort.go
+++ b/sort/sort.go
@@ -9,7 +9,7 @@ import (
 	"flag"
 )
 
-func readLines() []string {
+func ReadLines() []string {
 
 	r := bufio.NewReader(os.Stdin)
 	a := make([]string, 0)
@@ -28,7 +28,7 @@ func Run(args []string) int {
 	flagSet.Parse(args[1:])
 	status := 0
 
-	lines := readLines()
+	lines := ReadLines()
 	sort.Strings(lines)
 	for _, l := range lines {
 		fmt.Print(l)
diff --git a/yes/yes.go b/yes/yes.go
new file mode 100644
index 0000000..5bb827f
--- /dev/null
+++ b/yes/yes.go
@@ -0,0 +1,56 @@
+/* Yes program implementation. */
+package yes
+
+import(
+	"os"
+	"fmt"
+	"flag"
+	"strings"
+	"github.com/jienfak/goblin/sort"
+)
+
+func yes(s string){
+	for{
+		fmt.Print(s)
+	}
+}
+
+func Run(args []string) int {
+	var(
+		stdinFlag bool
+		nFlag bool
+		s string
+	)
+	status := 0
+	arg0 := args[0]
+	args = args[1:]
+	flagSet := flag.NewFlagSet(arg0, flag.ExitOnError)
+	flagSet.BoolVar(&stdinFlag, "s", false, "Read string from stdin.")
+	flagSet.BoolVar(&nFlag, "n", false, "Do not add net line character.")
+	flagSet.Usage = func() {
+		fmt.Fprintf(os.Stderr, "Usage of %s: %s [options] [string]\n", arg0, arg0)
+		flagSet.PrintDefaults()
+		
+	}
+	flagSet.Parse(args)
+	args = flagSet.Args()
+
+	if stdinFlag {
+		in := sort.ReadLines()
+		s = strings.Join(in, "")
+	} else {
+		if len(args)>0 {
+			s = strings.Join(args, " ")
+		} else {
+			s = "y"
+		}
+	}
+
+	if !nFlag {
+		s += "\n"
+	}
+
+	yes(s)
+
+	return status
+}