#! /usr/bin/perl

do 'date.perl' || die "Couldn't find date.perl";

open(old, $ARGV[0]) || die sprintf("opening ", $ARGV[0]);
open(new, $ARGV[1]) || die sprintf("opening ", $ARGV[1]);

@filetype = split(' ', <old>);
if ($filetype[0] !~ /cen/) {
    die sprintf("%s not a census file.  Stopped", $ARGV[0]);
}

@filetype = split(' ', <new>);
if ($filetype[0] !~ /cen/) {
    die sprintf("%s not a census file.  Stopped", $ARGV[1]);
}

$date0 = <old>;
$date1 = <new>;

if (do date($date0) > do date($date1)) {
    # old is later than new, so switch them.
    open(new, $ARGV[0]);
    open(old, $ARGV[1]);
    <old>; <old>;
    <new>; <new>;
}

while ($line = <new>) {
    @line = split(' ', $line);
    $sec = $line[0];
    $eff = $line[2];

    $neweff{$sec} = $eff;
    $lines{$sec} = $line;
}

while ($line = <old>) {
    @line = split(' ', $line);
    $sec = $line[0];
    $eff = $line[2];

    if ($eff != $neweff{$sec} && $neweff{$sec} == 100) {
	print $lines{$sec};
    }
}
