+9  A: 

You have discovered Bash's programmable completion feature.

unwind  2009-04-22 07:51:07
+5  A: 

See:

$ man bash

In particular, the section entitled "READLINE" and subsection "Programmable Completion"

Alnitak  2009-04-22 07:53:18
+5  A: 

FYI: In Ubuntu and/or Debian the scripts are at /etc/bash_completion.d/

 2009-04-25 15:50:52

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