#!/bin/rc

rfork e

switch($#*){
case 0
       file=/dev/sdC0/fossil
case 1
       file=$1
case *
       echo 'usage: lastfossil [/dev/sdC0/fossil]' >[1=2]
       exit usage
}

fn h2d { echo 'ibase=16;' print `{echo $1|tr a-z A-Z} |bc }
header=`{dd -bs 1024 -iseek 128 -count 1 -if $file >[2]/dev/null| xd -b | sed 1q}
bsize=`{h2d $header(8)^$header(9)}
super=`{h2d 0$header(10)^$header(11)^$header(12)^$header(13)}
x=`{dd -bs $bsize -iseek $super -count 1 -if $file >[2]/dev/null | xd -b |
       sed '1,2d;3s/^.......  .. .. //;4s/^.......  (.. .. .. .. .. ..).*/\1/;4q' | tr -d ' '}
echo vac:^$x(1)^$x(2)