tsort-check revision 1.1 
1#!/usr/bin/perl
2
3# Written by Marc Espie, 2001.
4# Public domain
5
6%order=();
7
8open(SORTED, shift) or die "No sorted output\n";
9while(<SORTED>) {
10	chomp;
11	$order{$_} = $i++;
12}
13close(SORTED);
14
15open(PAIRS, shift) or die "No pairs\n";
16undef $/;
17$_ = <PAIRS>;
18close(PAIRS);
19@pairs = split(/\s+/, $_);
20while (@pairs > 0) {
21	($a, $b) = (pop @pairs, pop @pairs);
22	next unless $order{$a} < $order{$b};
23	die "Bad pair $a $b\n";
24}
25