Display a colorful compact prompt with runtime of last command and a compact working directory.

timeprompt.bash

# PS1 = time compact_pwd >
# curated by budRich since 2017
# =============================
# 
# display runtime of last command and a compat PWD
# default time output is ms, if time is more then
# 1000ms, seconds is displayed instead.

# color of time is changed depending on the value.

# the compact PWD, displays the first character of
# each folder in PWD. If first character is '.',
# display the second character instead.

# examples
# --------
# `cd /usr/share`  
# 009 /u/s >

# `cd ~/.config`  
# 012 ~/c >

# screenshot
# ----------
# https://i.imgur.com/6yTX79Y.png

# inspiration
# -----------
# [Ville Laurikari](https://stackoverflow.com/a/1862762)
# [Henrik Nyh](https://github.com/henrik/dotfiles/blob/master/bash/prompt.sh)

# source
# ------
# https://gist.github.com/budRich/b1b0c4e8d882b78426ab720af5b1726b

timer_start() {
  timer=${timer:-$(date +%s%N | cut -b1-13)}
}

prompt_generator() {
  # regular colors
  local K="\[\033[0;30m\]"    # black
  local R="\[\033[0;31m\]"    # red
  local G="\[\033[0;32m\]"    # green
  local Y="\[\033[0;33m\]"    # yellow
  local B="\[\033[0;34m\]"    # blue
  local M="\[\033[0;35m\]"    # magenta
  local C="\[\033[0;36m\]"    # cyan
  local W="\[\033[0;37m\]"    # white

  # emphasized (bolded) colors
  local BK="\[\033[1;30m\]"
  local BR="\[\033[1;31m\]"
  local BG="\[\033[1;32m\]"
  local BY="\[\033[1;33m\]"
  local BB="\[\033[1;34m\]"
  local BM="\[\033[1;35m\]"
  local BC="\[\033[1;36m\]"
  local BW="\[\033[1;37m\]"

  # reset
  local RESET="\[\033[0;37m\]"

  # get time
  local milli=$(($(date +%s%N | cut -b1-13) - $timer))
  case $((
    milli >= 0 && milli <= 20   ? 1 :
    milli > 20 && milli <= 100  ? 2 :
    milli > 100 && milli <= 250 ? 3 :
    milli > 250 && milli <= 500 ? 4 :
    milli > 500 && milli <= 999 ? 5 :
    milli > 999 && milli <= 2000 ? 6 : 7)) in
      (1) psc="${G}" ;;
      (2) psc="${Y}" ;;
      (3) psc="${C}" ;;
      (4) psc="${B}" ;;
      (5) psc="${M}" ;;
      (6) psc="${R}" milli=$((milli/1000));;
      (7) psc="${R}" milli=$((milli/1000));;
  esac

  # pad ms or seconds with zeroes, so string length always is 3.
  local timmy=$(printf "%03d" $milli)

  # create a string with the first charcter of each folder in path
  local pth="$(pwd)"
  pth=${pth/${HOME}/'~'}
  local newpth=""
  apa=( ${pth//\//' '} )

  for d in ${apa[@]}; do
    [[ $d = '~' ]] && newpth='~' && continue
    # if first char is '.', grab the second
    [[ ${d:0:1} = '.' ]] \
      && newpth+="/${d:1:1}" || newpth+="/${d:0:1}"
  done

  PS1="${psc}${timmy} ${W}${newpth} ${B}>${RESET} "
  unset timer
}

# https://unix.stackexchange.com/a/65312
trap 'timer_start' DEBUG
PROMPT_COMMAND=prompt_generator