rot13 encoder/decoder
Rotates a byte value by thirteen characters.
Caveat
The name of this package is something of a misnomer: it does not implement the traditional ROT13 substitution cipher. In that cipher, the value "13" takes on special meaning because the cipher is supposed to operate on a 26-letter alphabet (2x13); because of this, one can encode and decode using the same algorithm (it is its own inverse). In contrast, this library operates on a full byte, so its "alphabet" is 256 characters instead of 26, and thus its algorithm is not its own inverse. If you are looking for a library to perform the ROT13 Caesar cipher, this is not for you.
Command-line use
There is a simple command line interface to this library. Clone the repo and
run go build cmd/rot13.go to build it.
Running rot13 -h will give you usage information:
Usage of ./rot13:
-encode
Encode the input string (default is to decode)
-input string
Input file; use '-' or leave blank to read from stdin
-output string
Output file; use '-' or leave blank to write to stdout
If you do not specify an input file, it will read from stdin; with no
output file specified, it will print results to stdout. Some examples:
$ echo 'hello, world!' > hello
$ rot13 -encode -input hello
uryy|9-|yq.
$ rot13 -encode -input hello -output hello_encoded
$ cat hello_encoded
uryy|9-|yq.
$ ./rot13 -input hello_encoded
hello, world!
$ echo 'hello, world!' | ./rot13 -encode
uryy|9-|yq.
$ echo 'hello, world!' | ./rot13 -encode | ./rot13
hello, world!
You can also use Go's testing facility to encode and decode. Supply the input/output file path as env variables and run:
INFILE=~/.lantern/global.yaml \
OUTFILE=~/.lantern/expanded_global.yaml \
go test -v -run TestFunctional