C:\Temp>type t.txt
This is a test sentence. And this is another one; Also so is this.
And by the way, this is the fourth sentence.

##</code><code>##

#!/usr/bin/perl

use strict;
use warnings;

my $s;
my @arr;

open(FILE, "<t.txt");

while(<FILE>) {
  chomp $_;
  $s .= $_;
}

@arr = $s =~ m/[A-Z].+?[.;]/g;
foreach (@arr) {
    print $_, "\n";
}

##</code><code>##

C:\Temp>t.pl
This is a test sentence.
And this is another one;
Also so is this.
And by the way, this is the fourth sentence.