2006-11-19 · in Ideas · 135 words

The completion facilities offered by readline and similar libraries are very useful for command-line users, but they aren't very easy to discover -- particularly when the completion rules are complicated, and the user may not know that their shell is able to completion what they're currently typing.

I'd like it if readline would show the current completion in a pale colour after what I'm currently typing -- so I can see instantly what would get completed if I hit Tab. This would invariably add some extra overhead, but in many cases (such as completing filenames in a directory, or command-line options from a parsed --help message) caching the results of the lookup the first time would get around this, and the completion lookup could start running in the background as soon as a completable word is detected.