--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/gosleep.go	Thu Nov 07 18:47:32 2019 +0900
@@ -0,0 +1,21 @@
+package main
+
+import (
+    "fmt"
+    "os"
+    "time"
+)
+
+func main() {
+    m := "1s"
+    if len(os.Args) > 1 {
+        m = fmt.Sprintf("%ss", os.Args[1])
+    }
+    d, err := time.ParseDuration(m)
+    if err != nil {
+        fmt.Println("bad time.")
+        os.Exit(1)
+    }
+    time.Sleep(d)
+}
+