Env specific colored prompt

#!/bin/bash

# Use the HOST_ENV variable to set the prompt color so the environment
# is obvious at the prompt

# Add it to .bashrc and optionally /etc/skel/.bashrc  

function setprompt {
  
  # Format is ESC[Value;...;Valuem
  # For example, for bold red text on black background \[\033[1;31;40m\]
  # Reference at http://ascii-table.com/ansi-escape-sequences.php

  BOLD="\[\033[1m\]"
  
  RED="\[\e[31m\]"  
  YELLOW="\[\e[33m\]"
  GREEN="\[\e[32m\]"
  BLUE="\[\e[34m\]"
  MAGENTA="\[\e[35m\]"
  CYAN="\[\e[36m\]"
  WHITE="\[\e[37m\]"
  OFF="\[\033[m\]"

  case $HOST_ENV in
    "prod" )
      PROMPT_COLOR=$RED
      ;;
    "staging" )
      PROMPT_COLOR=$YELLOW
      ;;
    "test" )
      PROMPT_COLOR=$WHITE
      ;;
    "dev" )
      PROMPT_COLOR=$CYAN
      ;;
    * )
      PROMPT_COLOR=$CYAN
      export HOST_ENV=scratch
  esac
    
  PS1="${PROMPT_COLOR}\u@${HOST_ENV}:\W${OFF} \$ "
}

PROMPT_COMMAND=setprompt