Tuesday, April 12, 2011

Wikipedia over DNS

A few days ago, I noticed a project that allowed querying Wikipedia over DNS. The way this works is to use the sub-domain query.wp.dg.cx and parse the DNS "text record", TXT, as defined in RFC 1035.

For example, to query for the term "computer":

$ host -t txt computer.wp.dg.cx
computer.wp.dg.cx descriptive text "A computer is a machine that mani
pulates data according to a list of instructions. The first devices t
hat resemble modern computers date to the mid-20th century (1940\226\
128\1471945), although the computer concept and various machines simi
lar to computers existed" " earlier. Early electronic computers were 
the size of a large room, consuming as much power as several hundred 
modern personal... http://a.vu/w:Computer"

Several months ago, Doug Coleman wrote the dns vocabulary to make DNS requests from Factor. Using it, you can lookup information for a hostname using a "pure Factor" version of host:

( scratchpad ) USE: tools.dns

( scratchpad ) "microsoft.com" host
microsoft.com has address 207.46.197.32
microsoft.com has address 207.46.232.182
microsoft.com mail is handled by 10 mail.messaging.microsoft.com

Yesterday, I spoke to Doug about using the dns vocabulary with the "Wikipedia over DNS" service. He discovered it required a few minor changes to support DNS TXT queries:

With a newer version of Factor that includes those changes, you can now make these queries:

( scratchpad ) USE: dns

( scratchpad ) "computer.wp.dg.cx" TXT.
A computer is a machine that manipulates data according to a list of 
instructions. The first devices that resemble modern computers date 
to the mid-20th century (1940–1945), although the computer concept a
nd various machines similar to computers existed earlier. Early elec
tronic computers were the size of a large room, consuming as much po
wer as several hundred modern personal... http://a.vu/w:Computer

1 comment:

_phred said...

Man, I love that the "shape" of the words to query DNS look just like the output of a command-line DNS tool like `nslookup`, `host`, or `dig`.

( scratchpad ) -- "google.com" A IN dns-query