#!usr/bin/perl

my $data;
my $currentline;
my @data;

print "Letter? ";
$letter = <STDIN>;            
open (DATA, "books.txt");
@data = <DATA>;
$currentline = 0;
foreach $data(@data) {
	$line = @data[$currentline];
	if ($line =~ /^$letter/i) {
		print "${line}";
	}
$currentline++
}