.bashrc

[...]

# PS1 setup
source ps1
PS1='$(set_prompt)'

ps1

#!/bin/bash

set_prompt()
{
   local last_cmd=$?
   local txtreset='$(tput sgr0)'
   local txtblack='$(tput setaf 0)'
   local txtred='$(tput setaf 1)'
   local txtgreen='$(tput setaf 2)'
   local txtyellow='$(tput setaf 3)'
   local txtblue='$(tput setaf 4)'
   local txtpurple='$(tput setaf 5)'
   local txtcyan='$(tput setaf 6)'
   local txtwhite='$(tput setaf 7)'
   # unicode "✗"
   local fancyx='\342\234\227'
   # unicode "✓"
   local checkmark='\342\234\223'
   # Line 2: current path
   PS1="\[$txtgreen\]\w "
   # User color: red for root, yellow for others
   if [[ $EUID == 0 ]]; then
       PS1+="\[$txtred\]"
   else
       PS1+="\[$txtyellow\]"
   fi
   # Line 3: user@host
   PS1+="\u\[$txtwhite\]@\h "
   # Line 4: a red "✗" or a green "✓" and the error number
   if [[ $last_cmd == 0 ]]; then
      PS1+="\[$txtgreen\]$checkmark \[$txtwhite\](0)"
   else
      PS1+="\[$txtred\]$fancyx \[$txtwhite\]($last_cmd)"
   fi
   # Line 4: green git branch
   PS1+="\[$txtgreen\]$(__git_ps1 ' (%s)')\[$txtwhite\]"
   # Line 4: good old prompt, $ for user, # for root
   PS1+=" \\$ "
}

Inspired from this thread on SO : https://stackoverflow.com/a/30963255/13879579