use strict;
 use warnings;

##</code><code>##

 my $fpath = '/somewhere/in';
 my $fname = 'input.dat';
 my $fn = "$fpath/$fname";
 
 die "$fn: $!" unless -f $fn;

##</code><code>##

 my $content;
 {
    open my $fh, '<', $fn or die "$fn: $!";
    local $/;
    $content = <$fh>;
 }

##</code><code>##

 my %counts;
 $counts{CHARS} =  length $content;
 $counts{WORDS} =  scalar( () = $content =~ /\b/g     ) / 2;
 $counts{SENTN} =  scalar( () = $content =~ /\w\.\W/g );
 $counts{PARAS} =  scalar( () = $content =~ /\n/g     ) + 1;

##</code><code>##

 for my $key (sort keys %counts) {
    print "$key ==> $counts{$key}\n"
 }