pscolor.bash

### Prompt customization ###

COLOR_ABBR_PS () {
    local str_max_length=3
    local norm_color='\[\033[33m\]'
    local abbr_color='\[\033[1;32m\]'
    local user_color='\[\033[1;34m\]'
    local no_color='\[\033[0m\]'
    local dir_sep="$norm_color/"

    local path="${PWD/$HOME}"
    local curwd nextdir dirnames
    [ "$path" != "$PWD" ] && curwd="$curwd$norm_color~"

    local i=0
    until [ "$path" == "$nextdir" ]; do
        path=${path#*/}
        nextdir=${path%%/*}
        dirnames[i]=$nextdir
        (( i += 1 ))
    done

    local lastdir=0
    [ "${#dirnames[@]}" -ne 0 ] && lastdir="$((${#dirnames[@]} - 1))"
    for i in $(seq 0 $lastdir); do
        if [ "$i" -eq $lastdir ]; then
            curwd="$curwd$dir_sep${dirnames[$i]}"
        elif [ "$i" -eq 0 ] || [ $((i+1)) -ge $lastdir ]; then
            if [ "${#dirnames[$i]}" -le "$str_max_length" ]; then
                curwd="$curwd$dir_sep${dirnames[$i]}"
            else
                curwd="$curwd$dir_sep$abbr_color${dirnames[$i]:0:$str_max_length}"
            fi
        else
            curwd="$curwd$dir_sep$abbr_color${dirnames[$i]:0:1}"
        fi
    done

    if [ -z "$abbr_host" ]; then
        abbr_host=$(echo "${HOSTNAME:-nil}" | sed 's/\..*$//')
        abbr_pat='[-_ ]'
        # Regex matching is even more finnicky than the rest of bash. Don't quote pat in [[ expr ]]
        [[ "$abbr_host" =~ $abbr_pat ]] && abbr_host=$(echo "$abbr_host" | sed 's/\([[:alnum:]]\)[[:alnum:]]*/\1/g')
    fi
    PS1="[$user_color\u@$abbr_host $curwd$no_color]$user_color\$ $no_color"
}
PROMPT_COMMAND="COLOR_ABBR_PS; $PROMPT_COMMAND"