[ILUG-BOM] Decoding offensive fortune cookies
Philip S Tellis
Mon Sep 22 09:42:38 IST 2003
On Sun, 21 Sep 2003, Nikhil Joshi wrote:
> man strfile gave that the alphabets are rotated 13 positions.
letters. an alphabet is a collection of symbols used in a grammar.
The english alphabet has 26 symbols,
base64 has 64,
the hexadecimal alphabet consists of 16,
and utf8 has much more.
> so i wrote a program , it now works. Can a shell script be written to
> achieve the same purpose ?
That aside, what you've seen is called ROT13 encryption. Decryption
using the shell is fairly simple using tr:
cat file | tr "a-zA-Z" "n-za-mN-ZA-M" > newfile
of course, this isn't portable across character sets. For that, you'd
have to list every single character... but I don't feel like doing that
It is not every question that deserves an answer.
-- Publilius Syrus
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GCS/ED/MU/TW d- s+: a- C+++ UL+++ P++++ L+++>$ E--- W+++ N- o-- K- w---
PS+ PE Y+ PGP+ t* X- R* tv b+ DI+++ D+ G++ e+++>$ h* r y
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