#! /bin/bash
# vi:set ts=8 sw=4 et sta:
#
# Author : Clark J. Wang <dearvoid at gmail.com>
# License: GPLv2
# 
# $Date$
# $Author$
# $HeadURL$
# $Revision$
#
#--------------------------------------------------------------------#

hexdump () 
{ 
    local sArg;
    local B E;
    for sArg in "$@";
    do
        if [[ "$sArg" == -* && "$sArg" != -[nsv] ]]; then
            command hexdump "$@";
            return $?;
        fi;
    done;
    if [ -t 1 ]; then
        eval "B=\$'\\033[44m'";
        eval "E=\$'\\033[0m'";
    fi;
    echo "         0  1  2  3   4  5  6  7   8  9  A  B   C  D  E  F  |0123456789ABCDEF|" 1>&2;
    echo "---------+--+--+--+---+--+--+--+---+--+--+--+---+--+--+--+--+----------------|" 1>&2;
    command hexdump -e '"%06_ax:" 4/1 " %02x" " " 4/1 " %02x" " " 4/1 " %02x" " " 4/1 " %02x" "  |"' \
                    -e '4/1 "%1_p" "'"$B"'" 4/1 "%1_p" "'"$E"'" 4/1 "%1_p" "'"$B"'" 4/1 "%1_p" "'"$E"'|\n"' \
                    "$@"
}

#--------------------------------------------------------------------#

# example
hexdump -n 123 /dev/urandom