Also, most emacs keybindings (C-u and C-w don't, but C-k, e, a and y do, at the very least) work in all Cocoa text fields. This (in general) means you have two copy buffers: the normal, system wide Cmd-C (or X), Cmd-V and the "Cocoa wide" C-k C-y buffer

The basic emacs shortcuts even work on iOS, if you're using a Bluetooth keyboard. Now the muscle memory works everywhere.

Right! Weirdly enough, C-k kills a word in (at least) the Editorial writing app in iOS7 (only writing app where I have tried since upgrading my iPad)

My favorite undocumented keybinding: C-t (transpose) for sloppy typers like me.

Didn't know C-t worked in Cocoa's. Thanks for pointing it out, always useful!

Just wanted to note:

C-u kills from cursor to start of line.

C-w kills from cursor to start of previous word. M-d is its friendly forward sibling.

Note: Ctrl-U and Ctrl-W are not from Emacs. They are instead from the same group as Ctrl-C for interrupt, Ctrl-D for End-of-File, etc; i.e. traditional Unix TTY driver keys. Run “stty -a” to see them all; the stty command can also be used to change them.

Thanks! fixed.

I never noticed C-u was from cursor. I tend to use it mostly from the end of the line.

And that's why C-e C-u is burned into my hands :^)

Is it any different from C-a C-k ? Both seem to stuff things into the kill ring (or whatever it's called in bash).

I guess lots of people leave C-a as the default escape key for screen.

Yea, there's the GNU Screen mapping conflict, and also I rarely use C-k so it's not in my muscle memory.

Makes sense; I use emacs in addition to just the emacs-like readline bindings, so C-u conflicts with "prefix argument". I also nest screen sessions using ^Z as the outer one's escape key and ^O as the inner one's, partly so I can use C-a / ^A.

Pressing ESC and then _ will insert the last argument of the last line. Repeat to go up in the history.

If you go through the command history and press CTRL-o on a line it will be executed and the command on the commandline will be replaced by the next line in the history.

Also M-. (meta-period). Keep banging on M-. to pull in the last argument of preceding commands.

With a numeric prefix argument N, it grabs the Nth-from-the-end argument of the previous command, so M-3 M-. grabs the 3rd-from-last argument from the previous command.

In Bash, you also can use the $_ variable which is the last argument of the previous command:

  $ stat /tmp/foobar
    File: `/tmp/foobar'
    Size: 0         	Blocks: 0          IO Block: 4096
    ...
  
  $ rm -v $_
  removed `/tmp/foobar'

You can also use `!$`.

!$ runs the last command. it's bad if the last command is of the form command arg... because it'd run command without every other argument passed in the command line

also alt + backspace, works similar to ctrl + w, but word is defined as only alphanumerics. Very useful when deleting parts of the long file paths because it will stop on / character (unlike C-w that deletes the whole path)