#! perl
use strict;
use warnings;

my $target = 'kitten';
my $string =  do { local $/; <DATA>; };
   $string =~ s/\n//g;
my $count  = () = $string =~ /\Q$target/g;

print "The target string '$target' occurs $count times in the file\n";

__DATA__
sushikitten
ilovethekit
tensushithe
kittenisthe