in reply to FIFO logfile done with flat file?

You could do it with a flat file. There's lots of ways. One script I had used a simple DBM file and went something like this (hope this is cut down right):
{ use Fcntl qw(:flock); my %h; my $size=5; sub ringopen { open(F, ">ring.lock") || die; flock(F, LOCK_EX); dbmopen(%h, "ring", 0666) || die; } sub ringclose { dbmclose(%h); close(F); } sub ringadd { ringopen(); local $_=$h{next}; delete $h{$_-$size} if (defined $_); $h{$h{next}++}=$_[0]; ringclose(); } sub ringdump { ringopen(); my @a=sort { $a <=> $b } grep /^\d+$/, keys %h; @a=@h{@a}; ringclose(); return @a; } }
And you used it like this:
for(0..9, 'a'..'z') { ringadd($_); } print ringdump();
To initialize the ring buffer, remove the ring* files.