added a bit of structure to fw.sh

fw.sh

@@ -1,3 +1,49 @@
 #!/bin/bash
 
+set -o errexit
+set -o pipefail
+set -o nounset
+
+fw_usage() {
+    :
+}
+
+fw_apply() {
+    :
+}
+
+fw_restore() {
+    :
+}
+
+fw_test() {
+    :
+}
+
+fw_flush() {
+    :
+}
+
+if [[ $# -gt 1 ]]; then
+    fw_usage
+    exit 1
+fi
+
+case $1 in
+    apply)
+        fw_apply
+        ;;
+    restore)
+        fw_restore
+        ;;
+    test)
+        fw_restore
+        ;;
+    *)
+        fw_usage
+        exit 1
+        ;;
+esac
+
 exit 0
+