Janitha Karunaratne - Welcome to the Present Moment

Sound of Data

Ever wonder what all the data in your hard drive sounds like? Or simply want to kill the silence in your server room? Simple, just direct devices into the audio device and listen to the sweet beatiful sound of your data (or other device). Reminds me of the good old days of 56k dialup. The more cluttered the data in your drive is, the more interesting the sound is. As root issue the following commands.

cat /dev/hda > /dev/audio

cat /dev/hdb2 > /dev/audio

cat /dev/urandom > /dev/audio

First line outputs raw data from your 1st hard drive (hda) to the audio device, second line outputs the data in your second partition in second drive directly into the audio device, and third just outputs random data into the audio which is simply just noise. Try connecting devices like the mouse or what ever else to your audio device or other devices, you just might get some interesting results. Hopefully I will get a hold of a old printer, want to output my hard drive directly into the parallel port and see what the printer does (or doesn't do).

Do this with caution. Don't be stupid and output the /dev/random into your hard drive or similar (not sure if this is possible but you get the idea). If you do something like this and lose all your life's work, remember that you were warned.

edit: For one reason or another your audio device in /dev might not be audio or dsp or what ever else you have so change that accordingly.

2005-06-25 14:54:40 | 25 Comments »

cj wrote

I'm definetly ready to do this just what do I do to make it quiet again?

2005-06-26 16:37:21 Home Page

Janitha wrote

I’m definetly ready to do this just what do I do to make it quiet again? CTRL+C to kill the cat process. If everything fails, as root you can just issue killall cat or kill the cat process through top or some other process manager.

2005-06-26 16:57:07 Home Page

Robynhub wrote

Nothing New... One day i've heard the god's voice... cat /boot/vmlinuz > /dev/dsp and what you get if you do it with a real wave file? ex. cat /media/audio/test.wav > /dev/dsp If your soundcard frequency settings are the same of the wave... you will hear the wave (almost) like a player. If they aren't... Funny thing... Speedy up or Sloooow down... Enjoy! http://jedinet.no-ip.org

2005-06-26 17:03:04 Home Page

michael wrote

to make it quite again, all you have to do is press Ctrl-C to end the command. at least that works for me.

2005-06-26 17:21:28 Home Page

joe wrote

this is noobish, but what program do i use for these commands? the dos prompt?

2005-06-26 18:01:54 Home Page

Janitha wrote

Joe: this is noobish, but what program do i use for these commands? the dos prompt? This possibly won't work in a windows enviornment, at least not this directly. I originally meant this for a Unix, Linux, *BSD or another *nix enviornment.

2005-06-26 18:19:00 Home Page

vengahombre wrote

Joe, these are Linux commands, and if you want to start understanding the really geek stuff, you showld learn something about Linux and you will see the light. Venga matrukas

2005-06-26 18:21:34 Home Page

hi' or 1=1-- wrote

hi' or 1=1--

2005-06-26 22:27:01 Home Page

MajinCline wrote

hey hi' or 1=1-, wow, you're an uber-1337 h4x0r where'd you learn those mad skill0rz?

2005-06-26 23:22:20 Home Page

*nixNoob wrote

Has anyone made this work under OS X? If so, what did you change to make it work?

2005-06-27 00:33:17 Home Page

Darksun4 wrote

I tried that kind of things when I was building a sound manager for linux. Interesting stuff to do : - Listen to a text file ( cat file.txt > /dev/dsp ) - Listen to an mp3 file ( cat name.mp3 > /dev/dsp ) But you can do an more interesting stuff cat /dev/dsp > textfile Then, everything that comes from your soundcard will be stored in a text file So, you can try this : cat afile.wav > /dev/dsp & cat /dev/dsp > bfile.wav & After a while killall cat and play with a normal player the bfile.wav ( or cat bfile.wav > /dev/dsp ) Funny stuff :)

2005-06-27 05:34:23 Home Page

Rickard wrote

Even more fun is listening to the network traffic... Try running sudo tcpdump -U -s 65535 -i eth0 -w /dev/dsp or, if you want to control the sample format and rate: sudo tcpdump -U -s 65535 -i eth0 -w - | play -s w -r 44100 -f s -t raw -c 2 - Remove 'sudo' and run as root if that doesn't work. This effectiviely pipes the data seen on the network right out your speakers. Then try telnetting to port 19 (chargen) of your favourite friendly nearby server and hear the sawtooth... FTP:ing wav-files gives an effect similar to the afile.wav > /dev/dsp shown above. Just using your web-browser also sounds pretty interesting...

2005-06-27 06:38:25 Home Page

Rickard wrote

Oh, maybe I should mention that you can control the volume when using play. Also, the line can be written in a easier-to-interpret way:sudo tcpdump -U -s 65535 -i eth0 -w - | play --size=w --rate=44100 --format=s --type=raw --channels=2 --volume=0.1where size=w is for 16-bit data (b for 8-bit, l for 32-bit), --format=s indicates signed data (u for unsigned), --channels=2 for stereo, and the volume ranges from 0 to 1. Also, change eth0 to the name of the network interface you wish to listen to (en0 in Mac OS X, lo for the local loopback interface). play, by the way, is included in the sox package, if you want to download it.

2005-06-27 06:58:23 Home Page

Mr. Kahn wrote

there is a java based application which takes tcpdump data and plays it out as java midi (works on linux and os x) http://www.smokinggun.com/projects/soundoftraffic

2005-06-27 08:23:04 Home Page

gambit wrote

if you don't recognize these as being *nix commands, the only thing that is "noobish" would be you...

2005-06-27 09:55:25 Home Page

Dan Mellstrom wrote

what the hell does this have to do with GTA:SA?

2005-06-27 10:29:26 Home Page

Nephroth wrote

Nothing Dan, that's just the previous blog entry title.

2005-06-27 10:50:40 Home Page

Oxy Clean wrote

Hey, what is the device for sound on OS X in the /dev directory?

2005-06-27 10:54:54 Home Page

crash893 wrote

can you use eth0 or something like that i tired and it says it doesnt recognize is there a way to output it to the video card?

2005-06-27 16:20:14 Home Page

Gavin wrote

Try cat'ing your hd to the term. Yields interesting results including totally screwing your term ocasionally. I also was left with a few files with very interesting filenames, would not have been able to delete them if not for autocomplete on the term (no X). Doing this with the net trafic looks interesting though.

2005-06-27 17:09:48 Home Page

windwaker wrote

This could be used as a form of audio encryption, or something like that.

2005-06-28 19:40:04 Home Page

someguy wrote

I know, I know this is a linux thing, and I know how much "linux people" cant stand winblows (neither can I, but I still use it ), but is there anyone here that knows of anyway of doing something similar in windows??

2005-06-28 22:38:32 Home Page

ice wrote

you could try cygwin / mingw if they have this.

2005-06-29 09:23:41 Home Page

Happosai wrote

Try: cat /dev/audio > /dev/audio & Then do something to make a sound on your computer (e.g. press CTRL+G for the system beep) = echo-cho-ho-o! ;) [Happosai]

2005-07-02 05:04:05 Home Page

Dr. Apocalypse wrote

I believe someone else has briefly mentioned my ideal already, but I'd like to expound upon it. This technique could be used to surreptitiously pass along a message to someone. Write a text file. Use this method to "play" your text file and record the sound, saving it as a .mp3 or .wav. Delete the original text file and send your new audio file to the intended recipient. Then all he has to do to decode it is listen to the file and have Linux output the sound as a text file. I don't think this qualifies as encryption; I'd say it's really just obfuscation, but it could be handy nonetheless.

2005-07-03 19:35:23 Home Page