open(DATA, "books.txt") or die "error opening file $!"; 
 
while (<DATA>) {
	@bookinfo = split(/\|/, $_);
	chomp(@bookinfo);
	if ($q{'lang'} eq '' || $bookinfo[1] eq $q{'lang'}) {
		$matchingwords=0;
		foreach $word(@search) {
			if ($_ =~ $word) { 
				$matchBooks[$numMatches] = @bookinfo unless ($matchingwords>0);
				$numMatches++;
				$matchingwords++;
			}
		}
	}	
}

if (@matchBooks>0) {

my $sortby;
if ($q{'sort'} eq 'author') {$sortby = 3;} else {$sortby = 2;}
@matchBooks = sort {${$a}[$sortby] cmp ${$b}[$sortby]} @matchBooks;

my $firstDis;
my $lastDis;
my $firstDisp;

if ($q{'first'}) {
	$firstDis = $q{'first'}; 
	$firstDisp = $q{'first'};} 
else {
	$firstDis = 1; 
	$firstDisp = 1;
}

if ($firstDis + 9 < $numMatches) {$lastDis = $firstDis + 9;} 
else {$lastDis = $firstDis + ($numMatches - $firstDis);}

$firstDisp = $firstDisp - 1;

print '<b>Matching Books</b><br>';
print 'There are '.@matchBooks.' matches.<br>';
print "${firstDis}-${lastDis} are listed below.<br><br>";
print "<nl>";

while ($firstDisp < $lastDis) { ... }