#!/usr/bin/perl -w

use strict;

use File::Find;
my ($string, @files);
($string, @files) = @ARGV;
@files = "." unless @files;
find sub {
       unless (-x) { 
          if (open (FILE, "$_")) {
             while (my $line = <FILE>) {
                print "$_: $line" if $line =~ /$string/i;
          }
          close FILE;
        } else {
          warn "Can't open $_: $!";
          next;
        }
       }
}, @files;