I went into this thinking "bah, readline, it's C-r, C-a, C-e, some kill and yank, what's to learn?". But it was Dave, and somehow there was a Part 3, so maybe there were something useful in there?

Wow, I was so wrong about knowing everything there is to know about readline. I don't know how useful the capitalization things are, and C-t I already knew about and I think it's mostly useful for when you have pressed C-t by mistake ... but M-b and M-f, OMG.

I have needed these for years. I usually hop around with C-left and C-right, but when you're one mosh, one tmux and one su down, usually all arrow keycodes are long gone, and it's all misery. Now with M-b and M-f my life quality will drastically improve!

Also interesting to know what the args thing is for. I've been vaguely aware of it as it's easy to trigger by mistake, but I think I will use it more now that I have been taught exactly what it does. Maybe for counting the length of git commit messages, for example. You want a 60-character max commit message length? M-6 0 C-b after you typed your message will show you by how much you overran the limit!

Thanks, Dave. As always a great contribution, even for those of us who may think we already know everything.