package require binary

proc hexdump {str} {
        set s ""
	set addr 0
	
	append s "[format "%07x" $addr]: "
	set t ""
        for {set i 0} {$i < [string length $str]} {incr i} {
		if {$i > 0 && [expr $i % 16] == 0} {
			append s "  $t\n"
			append s "[format "%07x" $addr]: "
			incr addr 16 
			set t ""
		} elseif {$i > 0 && [expr $i % 2] == 0} {
			append s " "
		}

		set char [string index $str $i]
                binary scan $char H2 cc
                append s $cc
		if {[string is print $char]} {
			append t $char
		} else {
			append t "."
		}
        }
	puts $s
}