+ my %sums;
+ for (1..$nart) {
+ <$s> =~ /\A220 / or _exit(4);
+ my $dig = Digest::SHA->new(1);
+ while (my $l = <$s>) {
+ last if $l eq ".\r\n";
+ $dig->add($l);
+ }
+ $dig = $dig->hexdigest;
+ $sums{$dig}++;
+ }
+ if ($nart) {
+ scalar(keys(%sums)) == 1 or _exit(5);
+ (values(%sums))[0] == $nart or _exit(6);
+ }