#! perl
use strict;
use warnings;

my $new_msg =
'I have <c> apples, <p> pineapples, and <t> pieces of fruit.
Yes, I do have <c> apples!';

my $count = 7;
my $pcnt  = 5;
my $total = $count + $pcnt;

print "\nBefore applying the substitutions, \$new_msg is:\n$new_msg\n";

$new_msg =~ s/<c>/$count/g;
$new_msg =~ s/<p>/$pcnt/g;
$new_msg =~ s/<t>/$total/g;

print "\nAfter applying the substitutions, \$new_msg is now:\n$new_msg\n";