diff --git a/ex01/hello_world.sh b/ex01/hello_world.sh
new file mode 100644
index 0000000..bd261a5
--- /dev/null
+++ b/ex01/hello_world.sh
@@ -0,0 +1,13 @@
+#! /bin/bash
+
+function hello_world() {
+  name="World"
+  if [ "$1" ]
+  then
+    name="$1"
+  fi
+
+    echo "Hello, $name!"
+}
+
+hello_world $1