#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;

sub fileParse {
    my ( @files ) = @_;

    my $refHash = {};

    open(my $fh, '<' , $files[0])
	or die "Could not open file '$files[0]' $!";

    my $pdus = do { local $/; <$fh> };

    close $fh
	or die "Could not close file '$files[0]' $!";

    chomp( $pdus );

    # my @matches = $pdus =~ /\{ (?: (?R) | [^{}]+ )+ \}/gx;
    my @matches = $pdus =~ /[^{}]+ | \{ (?: (?R) | [^{}]+ )+ \} /gx;

    # Trim leading and trailing white spaces
    s/^\s+|\s+$//g for (@matches);

    %{$refHash} = @matches;
    return $refHash;
}

my $final = fileParse( @ARGV );

my @sorted = ();
push @sorted, $_ for (sort keys %{$final});

print Dumper \@sorted;

__END__
$VAR1 = [
          '[     11] 25/2/2017-19:02:06.980 proces_name thanos-Rx: UDT',
          '[     12] 25/2/2017-19:02:06.996 proces_name thanos-Tx: UDT',
          '[     13] 25/2/2017-19:02:07.185 proces_name thanos-Rx: UDT',
          '[     14] 25/2/2017-19:02:07.227 proces_name thanos-Tx: UDT',
          '[     17] 25/2/2017-19:02:07.413 proces_name thanos-Tx: UDT',
          '[     18] 25/2/2017-19:02:09.794 proces_name thanos-Rx: UDT'
        ];