help: Enable/disable telnet protocol
delete:expression: " \
  if ! env | grep -q SSH_TTY=; then \
    if [[ \"`tty`\" == /dev/pts/* ]]; then \
      echo \"Please configure telnet settings via ssh or console.\"; \
      exit 1; \
    fi; \
  fi; \
  sudo /opt/vyatta/sbin/telnetd.init stop"
end:expression: " \
  if ! env | grep -q SSH_TTY=; then \
    if [[ \"`tty`\" == /dev/pts/* ]]; then \
      echo \"Please configure telnet settings via ssh or console.\"; \
      exit 1; \
    fi; \
  fi; \
  if [ -z \"$VAR(port/@)\" ]; then exit 0; fi; \
  sudo /opt/vyatta/sbin/telnetd.init restart $VAR(port/@)"