#!/bin/bash

# if no directory is supplied, use current directory
if [ ! "$1" ]; then
        set '.'
fi

# get absolute path
DIR=$(readlink -f "$1")/
# beautify
[ "$DIR" == "//" ] && DIR=/

cd "$DIR" 2> /dev/null || {
        echo -e "Error: Could not access '$DIR'.\n" >&2
        exit 1
}

echo -n "Scanning..";

# original source: http://blog.aclarke.eu/a-simple-treesize-shell-script-for-linux/
du -sk "$DIR".[!.]* "$DIR"* 2>/dev/null | sort -n | awk '
        BEGIN {
                split("KB,MB,GB,TB", Units, ",");
        }
        {
                if (skip == "") print "  [Done]\n";
                skip="true";
                sum+=$1

                u = 1;
                while ($1 >= 1024) {
                        $1 = $1 / 1024;
                        u += 1
                }
                $1 = sprintf("%6.1f %s  ", $1, Units[u]);

                # print size and basename of directory
                printf("%s ", $1)
                $0 = substr($0, index($0,$1)); # truncate $0 to get basename; $1 may not contain whole directory names, e.g. when a space character is included.
                system("basename \""$0"\"");

                # print size and full path of directory
                # print $0;
        }
        END {
                u = 1;
                while (sum >= 1024) {
                        sum = sum / 1024;
                        u += 1
                }
                # decimal 27 is the ASCII codepoint for the escape character
                printf("\n%c[0;32m%6.1f %s   Summary%c[0m\n\n", 27, sum, Units[u], 27);

                # same as above, but no color
                # printf("\n%6.1f %s   Summary\n\n", sum, Units[u]);
        }'