lr

#!/bin/bash
######################################################################
# Author: jrjbear@gmail.com
# Date: Sun Jan 12 17:04:30 2014
# File: lr
#
# Usage: lr [-w width] [-d depth] [dir...]
# Description: Recursively list contents of `dir' as a tree structure
######################################################################

readonly DFT_WIDTH=4
readonly DFT_LEVEL=6
readonly DFT_DIR="."

width="${DFT_WIDTH}"
max_level="${DFT_LEVEL}"
dashes=""
blanks=""

# $1 is the level of current directory
# $2 is the target directory
# $3 is the leading characters
function trace_dir()
{
    if (( $1 > "${max_level}" )); then
        echo "$3|${dashes}..."
        return
    fi

    local total=0
    for tryfile in $(ls $2); do
        let total=total+1;
    done

    local count=0
    for tryfile in $(ls $2); do
        echo "$3|${dashes}${tryfile}"
        let count=count+1
        local dir="$2/${tryfile}"
        if [[ -d "$dir" ]]; then
            if ((count == total)); then
                # This is the last entry
                trace_dir $(($1+1)) "${dir}" "$3 ${blanks}"
            else
                trace_dir $(($1+1)) "${dir}" "$3|${blanks}"
                echo "$3|${blanks}"
            fi
        fi
    done
}

function print_usage()
{
    echo "Usage: $0 [-w width] [-d depth] [dir...]" >&2
    echo "Recursively list contents of \`dir' (default is ${DFT_DIR}) as a tree structure" >&2
    echo "-w: output width of each level, default is ${DFT_WIDTH}" >&2
    echo "-d: maximum depth of subdirectory, default is ${DFT_LEVEL}" >&2
}

while getopts ":w:d:" opt; do
    case $opt in
        w ) width="${OPTARG}" ;;
        d ) max_level="${OPTARG}" ;;
        \?) print_usage; exit 1 ;;
    esac
done
shift $(($OPTIND-1))

for (( i = 1; i < "${width}"; ++i )); do
    dashes="${dashes}-"
    blanks="${blanks} "
done

if [[ -n "$@" ]]; then
    let count=0
    for dir in "$@"; do
        if ((count++ >= 1)); then
            echo -e "\n--------------------------------------------------------\n"
        fi
        
        if [[ ! -d "${dir}" ]]; then
            echo "${dir} is not a directory!" >&2
        else
            echo "${dir%/}/"
            trace_dir 1 "${dir}" ""
        fi
    done
else
    echo "./"
    trace_dir 1 "." ""
fi