#! /usr/bin/env perl
use strict;
use warnings;

BEGIN { die "usage: $0 <file> <word>" unless @ARGV==2 }

sub file_has_word {
  my ($fn, $w) = @_;
  open my $f, $fn or die "$fn: $!";
  local $/ = undef; # but why do you want this?
  return unless <$f> =~ /\Q$w/;
  1
}

print "found it!\n" if file_has_word(@ARGV);