https://susam.net/hn-bell.html

Hacker News Hug of Deaf

By Susam Pal on 05 Apr 2025


    "It's essentially the Hacker News Hug of Deaf." - @TonyTrapp

About three years ago, I set up a tiny netcat loop on one of my
Debian servers to accept arbitrary connections from the Hacker News
(HN) community. The loop ran for 24 hours and did exactly three
things whenever a client connected:

 1. Send a simple ok message to the client.
 2. Close the connection immediately.
 3. Make my terminal beep four times.

That's it! It was a playful experiment in response to a thread about
quirky, do-it-yourself alerting systems for friends and family. See
this HN thread for the original discussion. Here is the exact command
I ran on my server:

while true; do (echo ok | nc -q 1 -vlp 8000 2>&1; echo; date -u) | tee -a beeper.log; for i in 1 2 3 4; do printf '\a'; sleep 1; done & done

The nc command closes the connection immediately after sending the ok
message and runs an inner for loop in a background shell that
asynchronously prints the bell character to the terminal four times.
Meanwhile, the outer while command loops back quickly to run a new nc
process, thus making this one-liner script instantly ready to accept
the next incoming connection.

Soon after I shared this, members of the HN community began
connecting to the demo running on susam.net:8000. Anyone on the
Internet could use any client of their choice to connect. Here's how
I explained it in the HN thread:

    Now anytime someone connects to port 8000 of my system by any
    means, I will hear 4 beeps! The other party can use whatever
    client they have to connect to port 8000 of my system, e.g., a
    web browser, nc HOST 8000, curl HOST:8000, or even, ssh HOST -p
    8000, irssi -c HOST -p 8000, etc.

In the next 24 hours, I received over 4761 connections, each one
triggering four beeps. That's a total of 19044 terminal beeps echoing
throughout the day!

Graph Number of connections received every hour since 31 Jan 2022
10:00 UTC

The data for the above graph is available in beeper.log. Now, 4761
isn't a huge number in the grand scheme of things, but it was still
pretty cool to see people notice an obscure comment buried in a
regular HN thread, act on it, and make my terminal beep thousands of
time.

At the end of the day, this was a fun experiment. Pointless, but fun!
Computing isn't always about solving problems. Sometimes, it's also
about exploring quirky ideas. The joy is in the exploration, and
having others join in made it even more enjoyable. Activities like
this keep computing fun for me!

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Update on 10 Apr 2025: I shared this article on Hacker News today and
saw another surge in connections to my beeper loop.

Graph Number of connections received every hour since 10 Apr 2025
10:00 UTC

That's over 300 000 connections already! Much of the traffic seems to
have come from persistent client loops constantly connecting to my
beeper loop. It's great to see so much activity!

Comments | #unix | #shell | #networking | #technology
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