1993-03-16 - the recent mailing list flames

Header Data

From: hughes (Eric Hughes)
To: cypherpunks@toad.com
Message Hash: 393c1698d20d05c385f7aad2105ed94dee136c9e4aef1f0ec23ad76649ba4ee3
Message ID: <9303161732.AA07066@toad.com>
Reply To: N/A
UTC Datetime: 1993-03-16 17:32:07 UTC
Raw Date: Tue, 16 Mar 93 09:32:07 PST

Raw message

From: hughes (Eric Hughes)
Date: Tue, 16 Mar 93 09:32:07 PST
To: cypherpunks@toad.com
Subject: the recent mailing list flames
Message-ID: <9303161732.AA07066@toad.com>
MIME-Version: 1.0
Content-Type: text/plain

A word from your list maintainer.

Some people have no patience.  I was at CFP for three days last week,
soda has crashed twice (and is still down as of this writing), I've
had house guests.  I just this morning finished all the pending list
requests.  (All the deletions I did yesterday.)

One of the two loud complainers, mbrennan@netcom.com, had actually
doubled subscribed himself to the list.  I had already removed him
once, so I thought; I had moved him over to the -announce list.

Since we don't believe in security by obscurity here, the following
will generate a mail bomb for the next time _you_ want to be an

	yes "UNSUBSCRIBE ME\!\!\!" | head -30000

The program 'yes' (be repetitively affirmative) goes into an infinite
loop printing its argument.  When the pipe buffer fills up, the kernal
blocks the 'yes' process and invokes 'head', which partially empties
the buffer; 'yes' refills it.  This goes on until 'head' has seen
enough lines and terminates and closes the pipe.  Closing the pipe
then causes 'yes' to terminate.  So even though 'yes' is nominally an
infinite loop, when bound to a pipe and to a program which accepts a
bounded number of lines, it stops being an infinite loop.  I consider
this clever.

Enjoy, but do not deploy this one.