#!perl
#xyz.pl

use strict;
use warnings;

my $file = '3-4-111.txt';

open FH, '<', $file or die $!;
my(@lines) = <FH>;
@lines = sort @lines;
foreach my $line(@lines) {
    print $line, "\n";
}
close FH;

##</code><code>##


#!/usr/bin/perl

use strict;
use warnings;

my @files = glob('/your/dir/*.txt');
foreach my $file(@files) {
    print $file, "\n";
}