#!/usr/sbin/perl -w

use strict;
use Cwd;

my $the_directory = cwd;
#...

chdir $the_directory or die "Couldn't chdir to $the_directory; $!";

opendir(D, ".") or die "Couldnt open . ($the_directory): $!";

while ($file = readdir D) {
        next unless $file =~ /\.las$/i;
        
        open(FILE, "$file") || warn "Warning: can't open $file, skipping.\n";

        while (<FILE>) {
                chomp;

        #...