README.md in backticks-0.5.0 vs README.md in backticks-1.0.0rc1

@@ -79,14 +79,21 @@
 # at initialize-time
 r = Backticks::Runner.new(buffered:true)
 
 # or later on
 r.buffered = false
+
+# you can also specify invididual stream names to buffer
+r.buffered = [:stderr]
 ```
 
-### Interactivity
+When you read the `buffered` attribute of a Runner, it returns the list of
+stream names that are buffered; this means that even if you _write_ a boolean
+to this attribute, you will _read_ an Array of Symbol.
 
+### Interactivity and Real-Time Capture
+
 If you set `interactive:true` on the Runner, the console of the calling (Ruby)
 process is "tied" to the child's I/O streams, allowing the user to interact
 with the child process even as its input and output are captured for later use.
 
 If the child process will use raw input, you need to set the parent's console
@@ -94,9 +101,29 @@
 
 ```ruby
 require 'io/console'
 # In IRB, call raw! on same line as command; IRB prompt uses raw I/O
 STDOUT.raw! ; Backticks::Runner.new(interactive:true).run('vi').join
+```
+
+You can use the `Command#tap` method to intercept I/O streams in real time,
+with or without interactivity. To start the tap, pass a block to the method.
+Your block should accept two parameters: a Symbol stream name (:stdin,
+:stdout, :stderr) and a String with binary encoding that contains fresh
+input or output.
+
+The result of your block is used to decide what to do with the input/output:
+nil means "discard" and a modified string is captured in place of the original.
+
+Try loading the README in an editor with all of the vowels scrambled. Scroll
+around and notice how words change when they leave and enter the screen!
+
+```ruby
+STDOUT.raw! ; cmd = Backticks::Runner.new(interactive:true).run('vi', 'README.md') ; cmd.tap do |io, bytes|
+  vowels = 'aeiou'  
+  bytes.gsub!(/[#{vowels}]/) { vowels[rand(vowels.size)] } if io == :stdout
+  bytes
+end ; cmd.join ; nil
 ```
 
 ### Literally Overriding Ruby's Backticks
 
 It's a terrible idea, but you can use this gem to change the behavior of