oh-my-zsh/lib/termsupport.zsh

# Set terminal window and tab/icon title
#
# usage: title short_tab_title [long_window_title]
#
# See: http://www.faqs.org/docs/Linux-mini/Xterm-Title.html#ss3.1
# Fully supports screen, iterm, and probably most modern xterm and rxvt
# (In screen, only short_tab_title is used)
# Limited support for Apple Terminal (Terminal can't set window and tab separately)
function title {
  [[ "$EMACS" == *term* ]] && return

  # if $2 is unset use $1 as default
  # if it is set and empty, leave it as is
  : ${2=$1}

  if [[ "$TERM" == screen* ]]; then
    print -Pn "\ek$1:q\e\\" #set screen hardstatus, usually truncated at 20 chars
  elif [[ "$TERM" == xterm* ]] || [[ $TERM == rxvt* ]] || [[ $TERM == ansi ]] || [[ "$TERM_PROGRAM" == "iTerm.app" ]]; then
    print -Pn "\e]2;$2:q\a" #set window name
    print -Pn "\e]1;$1:q\a" #set icon (=tab) name
  fi
}

ZSH_THEME_TERM_TAB_TITLE_IDLE="%15<..<%~%<<" #15 char left truncated PWD
ZSH_THEME_TERM_TITLE_IDLE="%n@%m: %~"

# Runs before showing the prompt
function omz_termsupport_precmd {
  if [[ $DISABLE_AUTO_TITLE == true ]]; then
    return
  fi

  title $ZSH_THEME_TERM_TAB_TITLE_IDLE $ZSH_THEME_TERM_TITLE_IDLE

  # Notify Terminal.app of current directory using undocumented OSC sequence
  # found in OS X 10.9 and 10.10's /etc/bashrc
  if [[ $TERM_PROGRAM == Apple_Terminal ]] && [[ -z $INSIDE_EMACS ]]; then
    local PWD_URL="file://$HOSTNAME${PWD// /%20}"
    printf '\e]7;%s\a' "$PWD_URL"
  fi
}

# Runs before executing the command
function omz_termsupport_preexec {
  if [[ $DISABLE_AUTO_TITLE == true ]]; then
    return
  fi

  emulate -L zsh
  setopt extended_glob

  # cmd name only, or if this is sudo or ssh, the next cmd
  local CMD=${1[(wr)^(*=*|sudo|ssh|rake|-*)]:gs/%/%%}
  local LINE="${2:gs/%/%%}"

  title '$CMD' '%100>...>$LINE%<<'
}

precmd_functions+=(omz_termsupport_precmd)
preexec_functions+=(omz_termsupport_preexec)