This is a sentence. This is another sentence. This is a third
sentence, which also happens to be spanning a line. This is a
sentence as well... I think. This is an abbreviation, cf. the
list posted on Perlmonks. This is a sentence; this is the last
sentence.

##</code><code>##

This is a sentence.
This is another sentence.
This is a thirdsentence, which also happens to be spanning a line.
This is asentence as well.
I think.
This is an abbreviation, cf.
Perlmonks.
This is a sentence;

##</code><code>##

This is a sentence.
This is another sentence.
This is a third sentence, which also happens to be spanning a line.
This is a sentence as well... I think.
This is an abbreviation, cf.
the list posted on Perlmonks.
This is a sentence;
this is the last sentence.

##</code><code>##

#!/usr/bin/perl

use feature qw/say/;
use strict;
use warnings;

my $s;
my @arr;

while(<>) {
  chomp $_;
  $s .= $_ . " ";
}
@arr = $s =~ m/[A-Z].+?[.;](?=[^.;][A-Z]|\s*$)/g;
foreach (@arr) {
    say;
}

##</code><code>##

This is a sentence.
This is another sentence.
This is a third sentence, which also happens to be spanning a line.
This is a sentence as well...
I think.
This is an abbreviation, cf. the list posted on Perlmonks.