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atgreen · Nov 27, 2023 · a82cd62 · a82cd62
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 # privacy-output-stream
 A Common Lisp output stream that masks secret strings
+
+`privacy-output-stream` is a character output stream that wraps other
+streams, like `*standard-output*` and masks secrets from the output by
+replacing them with a series of `*`.
+
+For example, the following code:
+```
+(let ((*standard-output* (make-instance 'privacy-output-stream
+                                        :stream *standard-output*
+                                        :secrets '("passw0rd" "sekret"))))
+  (format t "Hello, my password is passw0rd~%"))
+```
+
+...prints:
+```
+Hello, my password is ********
+```
+
+```secrets``` is a list of secret values you want to mask in the final
+output.  They are processed in order, so I recommend that you sort
+your secrets by length in case one is a substring of another.
+
+Note also, that `privacy-output-stream` only masks secrets that are
+presented in full as part of a string or sequence being written to the
+stream.  Secrets written in fragments (by character or substring) will
+not be masked.
+
+Author and License
+-------------------
+
+``privacy-output-stream`` was written by [Anthony Green](https://github.com/atgreen),
+and is distributed under the terms of the MIT license.