Add echo

README.md

@@ -13,3 +13,4 @@ Implemeted utilities:
  * `yes`
  * `dirname`
  * `basename`
+ * `echo`

echo/echo.go

@@ -0,0 +1,24 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	s "strings"
+)
+
+var noNewline = flag.Bool("n", false, "Do not print the terminating newline.")
+
+func echo(strings []string, noNewline bool) {
+	str := s.Join(strings, " ")
+	if noNewline {
+		fmt.Print(str)
+	} else {
+		fmt.Println(str)
+	}
+}
+
+func main() {
+	flag.Parse()
+	echo(os.Args[1:], *noNewline)
+}