set_termtitle() {
  # escape '%' chars in "${1}", make nonprintables visible
  local a="${(V)1//\%/\%\%}"

  # Truncate command, and join lines.
  a="${a//[$'\r'$'\n']/}"

  [[ "${a}" = "zsh" ]] && { a="${(%)${:-%~}}" }

  case "${TERM}" in
    screen)
      # plain xterm title
      print -rn -- $'\e'"]2;${(%)${:-%m}}: ${a}"$'\a'

      # screen title (in ^A")
      print -rn -- $'\e'"k${a}"$'\e'$'\\'

      # screen location
      print -rn -- $'\e'"_${(%)${:-%m}}: ${a}"$'\e'$'\\'
      ;;
    xterm*|rxvt*)
      # plain xterm title
      print -rn -- $'\e'"]2;${(%)${:-%m}}: ${a}"$'\a'
      ;;
    *)
      ;;
  esac
}

my_prompt_precmd() {
    set_termtitle "zsh"
}

my_prompt_preexec() {
    set_termtitle "${1}"
}

typeset -ga precmd_functions
precmd_functions+=my_prompt_precmd

typeset -ga preexec_functions
preexec_functions+=my_prompt_preexec