solution

script.sh

@@ -0,0 +1,24 @@
+#! /bin/bash
+
+set -eu
+
+test $# -ne 2 && { echo "Usage: $0 start|stop|restart service" ; exit 42 ; }
+
+case $1 in
+   (start)
+      echo "starting $2"
+      ;;
+   (stop)
+      echo "stopping $2"
+      ;;
+   (restart)
+# ne marche que si le script est exécutable
+      $0 stop $2
+      $0 start $2
+      ;;
+   (*)
+      echo "action inconnue"
+      exit 1
+      ;;
+esac
+