bash_prompt

#!/usr/bin/env bash
# vim: ft=sh ts=4 sw=3
# Functions to generate a pretty useful bash prompt

# Check for interactive bash
[ -z "$BASH_VERSION" -a -z "$KSH_VERSION" -o -z "$PS1" ] && return

#
# Fancy PWD display function
#
# The home directory (HOME) is replaced with a ~
# The last pwdmaxlen characters of the PWD are displayed
# Leading partial directory names are striped off
# /home/me/stuff          -> ~/stuff               if USER=me
# /usr/share/big_dir_name -> ../share/big_dir_name if pwdmaxlen=20
#
bash_prompt_command() {
   # How many characters of the $PWD should be kept
   local pwdmaxlen=25
   # Indicate that there has been dir truncation
   local trunc_symbol=".."
   local dir=${PWD##*/}
   pwdmaxlen=$(( ( pwdmaxlen < ${#dir} ) ? ${#dir} : pwdmaxlen ))
   NEW_PWD=${PWD/#$HOME/\~}
   local pwdoffset=$(( ${#NEW_PWD} - pwdmaxlen ))
   if [ ${pwdoffset} -gt "0" ];
   then
      NEW_PWD=${NEW_PWD:$pwdoffset:$pwdmaxlen}
      NEW_PWD=${trunc_symbol}/${NEW_PWD#*/}
   fi
   # Display iTerm2 prompt if available.
   # See https://www.iterm2.com/documentation-shell-integration.html
   IT2_PS1='';
   if [ $(type -t "iterm2_prompt_mark") ];
   then
      IT2_PS1="$(iterm2_prompt_mark)";
   fi
   # Display git prompt if available.
   GIT_PS1='';
   if [ $(type -t "__git_ps1") ];
   then
      GIT_PS1_SHOWCOLORHINTS='';
      GIT_PS1=$(__git_ps1);
   fi
   # Display drush prompt if available.
   DRUSH_PS1='';
   if [ $(type -t "__drush_ps1") ];
   then
      DRUSH_PS1_SHOWCOLORHINTS='';
      DRUSH_PS1=$(__drush_ps1 " [%s]");
   fi
}

bash_prompt() {
   case $TERM in
      xterm*|rxvt*)
         local TITLEBAR='\[\033]0;\u:${NEW_PWD}${GIT_PS1}${DRUSH_PS1}\007\]';
         ;;
      *)
         local TITLEBAR="";
         ;;
   esac
   local NONE="\[\033[0m\]"      # unsets color to term's fg color

   # 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 EMK="\[\033[1;30m\]"
   local EMR="\[\033[1;31m\]"
   local EMG="\[\033[1;32m\]"
   local EMY="\[\033[1;33m\]"
   local EMB="\[\033[1;34m\]"
   local EMM="\[\033[1;35m\]"
   local EMC="\[\033[1;36m\]"
   local EMW="\[\033[1;37m\]"

   # background colors
   local BGK="\[\033[40m\]"
   local BGR="\[\033[41m\]"
   local BGG="\[\033[42m\]"
   local BGY="\[\033[43m\]"
   local BGB="\[\033[44m\]"
   local BGM="\[\033[45m\]"
   local BGC="\[\033[46m\]"
   local BGW="\[\033[47m\]"

   local UC=$G                   # user name's color
   local MC=$C                   # machine name's color
   local PC=$EMB                 # path's color
   local GC=$EMM                 # git information color
   local DC=$EMY                 # Drupal information color

   [ $UID -eq "0" ] && UC=$R     # root's color

   PS1="${TITLEBAR}\n\${IT2_PS1}${EMG}[${UC}\u${EMG}@${MC}\h ${PC}\${NEW_PWD}${GC}\${GIT_PS1}${DC}\${DRUSH_PS1}${EMG}]\n${UC}\\$ ${NONE}"
   # without colors: PS1="[\u@\h \${NEW_PWD}\${GIT_PS1}\${DRUSH_PS1}]\\$ "
   # extra backslash in front of closing \$ to make bash colorize the prompt
}

# Enable the prompt.
# Execute this command every time a prompt is drawn
export PROMPT_COMMAND=bash_prompt_command;
# Define the text to display beside the prompt
bash_prompt
# Clean-up the functions we no-longer require
unset bash_prompt

# Configure Git prompt settings defaults. 
# These settings provide the best performance. 
# Allowed values described in `bash_prompt_git'. 
export GIT_PS1_SHOWCOLORHINTS='';
export GIT_PS1_SHOWDIRTYSTATE='';
export GIT_PS1_SHOWSTASHSTATE=''
export GIT_PS1_SHOWUNTRACKEDFILES='';
export GIT_PS1_SHOWUPSTREAM='';
export GIT_PS1_DESCRIBE_STYLE='';