#!/usr/bin/perl -w
# print_line-v3 - DB_File style
use DB_File;
use Fcntl;

@ARGV == 2 or
    die "usage: print_line FILENAME LINE_NUMBER\n";

($filename, $line_number) = @ARGV;
$tie = tie(@lines, "DB_File", $filename, O_RDWR, 0666, $DB_RECNO)
        or die "Cannot open file $filename: $!\n";

unless ($line_number < $tie->length) {
    die "Didn't find line $line_number in $filename\n"
}

print $lines[$line_number-1];                        # easy, eh?