22 Sep
2003
22 Sep
'03
4:12 a.m.
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 right now.
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