Easy start script: refactor and correct option processing

builder/startup/deb/kasmvncserver-easy-start

@@ -8,6 +8,8 @@ cert_group=ssl-cert
 xstartup_script=~/.vnc/xstartup
 de_was_selected_file="$HOME/.vnc/.kasmvncserver-easy-start-de-was-selected"
 
+action=start
+
 manual_xstartup_choice="Manually edit xstartup"
 declare -A all_desktop_environments=(
   [Cinnamon]=cinnamon-session
@@ -122,25 +124,47 @@ SCRIPT
   chmod +x "$xstartup_script"
 }
 
-if [[ "$1" = "--help" ]]; then
+enable_debug() {
+  debug=1
+  log_option="-log *:stderr:100"
+}
+
+kill_vnc_server() {
+  vncserver -kill $display
+}
+
+process_cli_options() {
+  for option in "$@"; do
+    case "$option" in
+      --help)
+        show_help
+        exit
+        ;;
+      -d)
+        enable_debug
+        ;;
+      -kill)
+        kill_vnc_server
+        exit
+        ;;
+      -select-de)
+        action=select-de-and-start
+        ;;
+    esac
+  done
+}
+
+show_help() {
   cat >&2 <<-USAGE
 Usage: `basename $0` [options]
   -d          Debug output
   -kill       Kill vncserver
+  -select-de  Select desktop environent to run
   --help      show this help
 USAGE
-  exit
+}
-fi
 
-if [[ "$1" = "-d" ]]; then
+process_cli_options "$@"
-  debug=1
-  log_option="-log *:stderr:100"
-fi
-
-action=start
-if [[ "$1" = "-kill" ]]; then
-  action=kill
-fi
 
 if groups | grep -qvw ssl-cert; then
   cat <<-EOF
@@ -150,11 +174,6 @@ EOF
   exit 1
 fi
 
-if [[ "$action" = "kill" ]]; then
-  vncserver -kill $display
-  exit
-fi
-
 if ! de_was_selected; then
   detect_desktop_environments
   ask_user_to_choose_de