Given ikegami's code:

while (<$fh_log>) {
   my ($month, $user) = /^LOGGING: \S+?-(\S+) \S+: STARTING FLUSH: (\S
++)$/
      or next;

   $flushes{$month}{$user}++;
   $flushes{$month}{TOTAL}++;
}
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which produces a data structure similar to what this code does:

my %flushes = (
    'Aug-2008' => {
        'ces' => 5,
        'cjc' => 7,
        'TOTAL' => 12,
    },
    'Jul-2008' => {
        'mhs' => 1,
        'ces' => 3,
        'cjc' => 4,
        'TOTAL' => 8,
    },
);
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you could do this to get the output:

for my $month ( keys %flushes ) {
    print $month . "\n";
    print 'Total: ' . $flushes{$month}{TOTAL} . "\n#####\n";
    for my $user ( sort keys %{ $flushes{$month} } ) {
        next if $user eq 'TOTAL';
        printf "%-20s%3d\n", $user, $flushes{$month}{$user};
    }
    print "\n";
}
[download]

If you want higher marks, you might want to use strictures and warnings. That will require declaring %flushes in the proper scope. You'll need to add opening the file and error checks to his code, anyway.

If you'd rather sort by uses (descending) than by their user names, you could try this instead:

for my $month ( keys %flushes ) {
    print $month . "\n";
    print 'Total: ' . $flushes{$month}{TOTAL} . "\n#####\n";
    for my $user (
        sort { $flushes{$month}{$b} <=> $flushes{$month}{$a} } keys %{
+ $flushes{$month} }
    ) {
        next if $user eq 'TOTAL';
        printf "%-20s%3d\n", $user, $flushes{$month}{$user};
    }
    print "\n";
}
[download]

Now, is there a particular part of that you're having problems understanding or did you just want someone to write the code for you?