ZLE: Key bindings codes list

zlezsh

I know that in

bindkey '\ep' autosuggest-accept-suggested-small-word

the \e refers to the ⎇ Alt key. I also know that C- refers to the ⎈ Ctrl key.

Is there a list referencing all the keys because I have the hardest time to understand how ZLE works and which key combination I should use to bind autosuggest-accept-suggested-small-word to a keyboard shortcut starting with the ⌘ Cmd key.

For example: To which keys are these keybindings referring: ^~u, ~w, ^@j (these are keybindings that I found in the ttscoff keybindings settings file)?

Best Answer

^ in ZSH (and many other softwares; see for example stty -a) refers to control key e.g. for control-L to clear the screen one might find in the ZSH keybindings list

% bindkey | grep clear
"^L" clear-screen
%

I cannot comment on how ^~u ~w ^@j in the ttscoff keybindings relate to ZSH. That software appears unrelated to ZSH; the full list of what ZSH recognizes can be found in the zshzle(1) manual, which for some version of ZSH (do instead check the manual for the version you have and do not blindly assume that this list is correct for that version of ZSH) includes

          \a     bell character
          \b     backspace
          \e, \E escape
          \f     form feed
          \n     linefeed (newline)
          \r     carriage return
          \t     horizontal tab
          \v     vertical tab
          \NNN   character code in octal
          \xNN   character code in hexadecimal
          \uNNNN unicode character code in hexadecimal
          \UNNNNNNNN
                 unicode character code in hexadecimal
          \M[-]X character with meta bit set
          \C[-]X control character
          ^X     control character

To make the Apple command key generate codes in the terminal requires that the terminal program be configured to do so; the instructions for this will vary depending on whether you are using Terminal.app or iTerm.app or something else (dig around in the preferences or check the manual).

With iTerm.app (this may change; GUI apps tend to move things around over time) try the iTerm2 menu, Preferences, Keys, find the widget to add something, and then "send hex code" 0x02

Then in ZSH bindkey this sequence

% xxd
^B
00000000: 020a                                     ..
% screencapture -s hexcode.png
% bindkey '^B' clear-screen
%

and now splat-shift-option-O should cause ZSH to clear the screen; instead bindkey your desired widget and set that in your configuration:

bindkey '^B' autosuggest-accept-suggested-small-word

or whatever other binding that works for you. Be sure to run bindkey and inspect that no other existing widget that you want to use uses the key code...

Related Solutions

Bash – Delete backward until met a char, like alt + bksp

Search backward for :, then delete to the end of the line: Ctrl+R : Alt+D. Ctrl+R is the history search command, and the line you're editing is part of the history. Most commands, including Alt+D, terminate the incremental history search and have their usual effect.

In vi mode: F:C

This applies in both bash and zsh (in the default configuration, I don't guarantee that there aren't exotic combinations of options in zsh that will make it react differently, and of course this assumes the default keybindings).

Key bindings table

The interface between a terminal application and a terminal emulator (or hardware terminal) transmits bytes, not keys. Function keys such as cursor movement keys are translated into escape sequences (beginning with the escape character ESC a.k.a. \e a.k.a. \033 a.k.a. 0x1b a.k.a. ^[). The same goes for combinations of a function key or a character key with modifiers, though not all terminals send different sequences for all the different modifier combinations. A few keys are sent encoded as control characters (e.g. Tab → Ctrl-I = \t = \011).

As you can see, there are many ways to describe control characters. Some have a name, corresponding to their traditional function (e.g. Tab, Line feed); those tend to have a backslash+letter combination that you can use inside $'…' or in an argument to echo or print (as well as in sed regular expressions and in string literals in awk, C and other languages (note that different tools may have a slightly different set of escape sequences)). You can use backslash+octal (e.g. \033) in these contexts as well.

There is some variation as to which escape sequence terminals send for each key. Fortunately, there is almost no overlap: there are very few character sequences that mean different keys on different terminal. The main problem is character 127 = \177 = 0x7f which is most often Backspace nowadays but sometimes Delete.

^[OF and ^[[F (i.e. \eOF and \e[F) are the two common escape sequences sent by End. ^E (i.e. \005) is the Emacs key binding (Ctrl+E) for end-of-line.

To see what your terminal emulator sends for a particular key or key combination, press Ctrl+V and then the key in question. This inserts the first character of the escape sequence literally. Escape sequences normally consist of an escape character followed by printable characters, so the rest of the escape sequence is inserted literally too.

The Terminfo database contains the escape sequences for some keys. You'll find the list of Terminfo capabilities in the terminfo(5) man page on your system. In zsh, you can list the values in the database through the terminfo associative array. Beware when printing out values that they contain escape sequences which are also interpreted by the terminal when displayed, so print them in a quoted form.

% print -lr ${(q)terminfo[kend]}
$'\033'OF

See How do keyboard input and text output work? for a more complete overview of what happens when you press a key. It isn't necessary to understand key bindings in zsh.

Best Answer

Related Solutions

Bash – Delete backward until met a char, like alt + bksp

Key bindings table

Related Question