# Useful terminal character enhancements

    export HB=$(/usr/bin/tput dim)          # dim text
    export HV=$(/usr/bin/tput smso)         # 1/2 bright inverse
    export IV=$(/usr/bin/tput bold)         # inverse
    export UL=$(/usr/bin/tput smul)         # underline
    export BL=$(/usr/bin/tput blink)        # blink
    export EE=$(/usr/bin/tput sgr0)         # end all enhancements

#  Setup the prompt string $PS1 
 
# Set these values adjust the PS1 prompt:

# PS1HOST=true or false   (default is true - show hostname)
# PS1USER=true or false   (default is true - show username)
# PS1DIR=0 1 or 2         (default is 2 - show lowest 2 levels of PWD) 
# PROMPT=# or $           (default is $ for a stabdard user)

    PS1HOST=${PS1HOST:-/usr/bin/true}    # default = true
    PS1USER=${PS1USER:-/usr/bin/true}    # default = true
    PROMPT=${PROMPT:-$}                  # default = $
    USER=""
    HN=""

# Some terminals do not have 1/2 bright inverse so let's test this
# capability and substitute underline rather than $HV

    if tput smso > /dev/null
    then 
       HVUL=$HV
    else
       HVUL=$UL
    fi

# Set the hostname and username fields (if false, no field)

    $PS1HOST && HN="$HVUL$(/usr/bin/hostname)"
    $PS1USER && USER="$HB $(/usr/bin/id -un)" 

# To change the active PWD at every prompt, we must set the
# PS1 value here using apostrophes ' ' to force an evaluation
# of the current $PWD content. 

# Note the use of $EE to end the enhancements before the shell
#   prompt. Many terminals will stay in a specific setting onto
#   additional lines. $EE turns off all the enhancements.
 
    PS1DIR=${PS1DIR:-2}
    case $PS1DIR in
       1 ) export PS1='$HN$USER $IV${PWD##*/}$EE $PROMPT '
           ;;
       2 ) export PS1='$HN$USER $IV${PWD##${PWD%/*/*}/}$EE $PROMPT '
           ;;
       * ) export PS1='$PROMPT '
           ;;
    esac