This may be close to what you want

use strict;
use warnings;

my $lines    = 0;
my $mystring = '';
my $chars    = 0;
my $word_cnt = 0;

while(<DATA>) {
    my $str = $_;
    $chars += length($str);
    $lines++ ;
    my @words = grep /\w/, ($str =~ /\b\w*\b/g);
    $word_cnt += $#words + 1;
    $str =~ s/( |,|\.|\n|\t)//g;
    $mystring .= lc($str);
}

print "Lines: $lines\n";
print "Words: $word_cnt\n";
print "Characters: $chars\n";
print "Total String: $mystring\n";

__DATA__
The quick brown fox jumps over the lazy dog.
The quick brown fox jumps over the lazy dog.
The quick brown fox jumps over the lazy dog.
The quick brown fox jumps over the lazy dog.
[download]

Outputs

Lines: 4
Words: 36
Characters: 180
Total String: thequickbrownfoxjumpsoverthelazydogthequickbrownfoxjumps
+overthelazydogthequickbrownfoxjumpsoverthelazydogthequickbrownfoxjump
+soverthelazydog
[download]