well it's more than one line but should print the number of unique lines(untested) 
open(FILE,"whatever.log");
my %seen = ();
while(my $line = <FILE>){
        my ($first) = ($line =~ /^(/S+)/)[0];
        $seen{$first}++;
}
print scalar keys %seen;

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In reply to Re: Counting lines starting with a unique string by thunders
in thread Counting lines starting with a unique string by ezekiel

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