Firstly, you really should be posting comments and follow-up code under the same thread rather than starting new threads for each new discussion on the thread.

With the code here ...

while (<CONFIGFILE>) {
    chomp;
    $file = $_;
    open(FILE, $file) or die "Can't open $file";
    binmode(FILE);
    $md5 = Digest::MD5->new;
    while (<FILE>) {
        $md5->add($_);
    }
    close(FILE);
    print RESULTS $md5->b64digest, " ", $file, "\n";
    #print $md5->b64digest, "\n";
    $a=$a+1;
}
[download]

... you could write this a lot more neatly making use of the addfile and reset methods of Digest::MD5 rather than iterating through each line of the file and constructing a new Digest::MD5 object with each loop. eg.

my $md5 = Digest::MD5->new;

while (<CONFIGFILE>) {
    chomp;
    $md5->reset;
    {
        local *FILE;
        open (FILE, $_) || warn $!;
        binmode FILE;
        $md5->addfile(*FILE);
        close FILE;
    }

    #   stuff with $md5 digest methods
}
[download]

Now, its beyond this segment of code that the purpose of some of the code flow became a little hazy to me - The second while loop could me written differently with a direct comparison between scalar contexts of the arrays without the use of the superfluous counter variables - Also too, the use of $a and $b as variable names is not a good choice given the magic role which these play within Perl. eg. sort.

Anyhow, while I would write the code differently, if it does what you need, good luck and well done on your efforts thus far.

 

perl -e 's&&rob@cowsnet.com.au&&&split/[@.]/&&s&.com.&_&&&print'