Charlie Harvey

ROT13 tools

This tool lets you ROT13 (and unROT13) strings of text. There is a ROT13 api for programmers.





About ROT13

illustration of ROT13 process

ROT13 is a variant of the simplest crypto imaginable — a substitution cipher. It ROTates the letters of your plain text message 13 places through the alphabet. Unlike other ROT-n ciphers (where n is a number other than 13) ROT13ing a message twice gives the original plain text of the message.

A lot of people used to use ROT13 on usenet to hide potentially offensive material or for spolier-type material where they didn’t want to give away the ending. My implementation just uses the tr function to run the rotation thus $msg =~ tr |A-Za-z|N-ZA-Mn-za-m|;

Using the API

The API is as straightforward at it gets and provides only a single endpoint — http://charlieharvey.org.uk/rot13/api. You include the message to be ROT13ed in the URL string. By default you get back a JSON object with a single field, msg which is your ROT13ed message. You can provide an accept-type header to get back YAML or XML versions. Here are some examples using curl.$ curl http://charlieharvey.org.uk/rot13/api/hello { "msg" : "uryyb" } $ curl -H'Accept-type:text/xml' http://charlieharvey.org.uk/rot13/api/hello <data msg="uryyb" /> $ curl -H'Accept-type:text/x-yaml' http://charlieharvey.org.uk/rot13/api/hello --- msg: uryyb $ curl -H'Accept-type:application/json' http://charlieharvey.org.uk/rot13/api/hello { "msg" : "uryyb" }