hmmmmm. this is certainly a stubborn little script we're dealing with. alright.

About Warnings
use warnings; is equivalent to putting the little -w at the end of your 'shebang line'. So if your Perl implementation does not grok use warnings' change your script to read #!/usr/bin/perl -w at the top of your code. This will have the same effect. Warnings have the effect of telling Perl you want it to complain about any code that's incorrect or not clear. An example would be (at least until Perl 6 comes out):

Without warnings, Perl will compile and run the following code

    # this is a slice, probably not intended
    @someList[0] = 'foo';
[download]

but with warnings, if you tried to use the above code, Perl will complain:

@someList[0] better written as $someList[0]
[download]

which is what you want. Using warnings (either through 'use warnings' or the '-w' flag is one of the most important steps you can take towards being a good Perl programmer.

Back To the Problem At Hand
That all being said, 'use warnings;' is not needed to make this script run correctly.

Some Questions

• What version of Perl are you using, and on which platform?
• How big are the directories that you're trying to parse?
• Are the directories local or are they network shares?

And have you tried adding some debugging to the script to see what it's doing? Maybe you want to do something like:

#!/usr/bin/perl -w #alternative warning syntax
use strict;

use File::Find;

#########################################################
# a debugging variable
#########################################################
my $totalChanges;

my @dirs = qw(.);

find ( { wanted => \&change, no_chdir => 1}, @dirs );

sub change
{
    my $file = $File::Find::name;
    
    if ( -f $file && $file =~ /\.html$/ )
    {
        ###################################
        # debugging print statement
        ###################################

        print "going into $file\n";
        my $buffer;
        open(IN, $file) or warn "CAN'T OPEN $file!\n";

        {
            local $/ = undef;
            $buffer = (<IN>);
        }
        
        close IN;
        
        my $changecount = ($buffer =~ s/FOO/BAR/gi);
        
        if ($changecount)
        {
           #######################################
           # increment debug variable
           #######################################
           $totalChanges++;
          
           #######################################
           # debugging statement
           #######################################
           print "changed $changecount instances in $file\n";
            open(OPF,">$file") or warn "NOT OPENING $file FOR MOD, $!\
+n";
            print OPF "$buffer";
            close OPF;
        }
    }
}

###################################################
# debugging statement
###################################################
print "$totalChanges files changed\n";
[download]

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.