#!/usr/bin/perl

use strict;
use warnings;

my ($file,$var) = @ARGV;
die "USAGE: $0 file word\n" unless $file and $var;

open GETARG, '<', $file or die "Can't open $file: $!\n";
while (<GETARG>) {
   s/\.$// if /$var/;
   print;
}

close GETARG or die "Couldn't close $file: $!\n";

##</code><code>##

perl -pe's/\.$// if /word/' file