> For the complete documentation index, see [llms.txt](https://trizen.gitbook.io/sidef-lang/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://trizen.gitbook.io/sidef-lang/programming_tasks/r/rot-13.md).

# Rot-13

```ruby
# Returns a copy of 's' with rot13 encoding.
func rot13(s) {
    s.tr('A-Za-z', 'N-ZA-Mn-za-m')
}

# Perform rot13 on standard input.
STDIN.each { |line| say rot13(line) }
```