While using Vim under Linux Mint 20.2 (with NumLock off), when I hit the NumPad center key (5), a line is inserted above the current line, a capital E appears, and I am left in Insert mode. I often mistakenly hit the 5 key when trying to navigate using the NumPad cursor keys, and I would love to redefine the NumPad 5 to do nothing. I've tried remapping the key in .vimrc (using noremap <Esc>[E <Esc>, for example), but it has no effect. Note, the ANSI sequence produced when I press the NumPad5 is \033[E
FYI, I have TERM=xterm-256color.
Note: this answer generally talks about the numpad in a no-numlock context. All numbers on the numpad can be mapped when numlock is on by using <k0>...<k9>. References to the mapability of keys is therefore in a no-numlock context
Note, the ANSI sequence produced when I press the NumPad5 is \033[E
Vim doesn't see it that way.
On my system (Mint 20.2 with Cinnamon under X11), no-numlock 5 produces ^[OE. That O is very important to the observed behavior. o means "go to a new line under and enter insert mode", and O means the exact same thing, but to a new line above. The next E is then interpreted as an insert mode character, because Vim.
Moreover, esc is represented as ^[, so for mapping purposes, you only need <esc>. This point is easier to demonstrate in Vim:
^[ is additionally treated as a single character. If you want to play around with this, pop into insert mode and press <C-v>. The next key(bind) you press will be printed literally to the screen
This means what you actually want is:
nnoremap <Esc>OE <nop>
Note that I'm not sure how terminal input processing applies here; this may only hold for certain terminals, or even only apply to X11.
Another trick in general here, and a way to make sure the keycode is correct for your terminal, is that you can type :nnoremap , and then press Ctrl+v+Numpad 5. This will give you the exact keycode as Vim sees it, which you then can map to whatever you have planned.
If you do this in gVim, however, you'll find that numpad 5 without numlock doesn't actually produce a keycode detectable by gVim. This presumably means it can't be mapped (unless there's some way I just don't know about - if there is, please prove me wrong). But because it doesn't spew out a terminal code, there's the added benefit of not needing to remap it for this particular purpose, because it doesn't have the problem you're trying to avoid here in the first place.
romainl mentioned :help key-notation in the comments, but there's something to keep in mind here:
gVim not producing a keycode usually means there isn't one. <C-v> followed by numpad 9 in gVim produces <kPageUp>, but followed by numpad 5, it doesn't produce anything. Secondly, if you read :h key-notation, you'll see that it only defines home, end, up, and down, as well as the various operators, enter, and the decimal point. 2, 4, 6, and 8 are all registered as normal arrow keys, meaning <Down>, <Left>, <Right>, and <Up>. There's no way to detect these on the numpad specifically, but that's not really important.
If you've been keeping track, you'll find that numpad 5 is excluded. Note: When numlock is on, <C-v> + numpad 5 doesn't output anything in Vim or gVim, because the definition is:
Insert the next non-digit literally.
See :h i_CTRL-V.
TL;DR:
<C-v> is your friend.
Use:
nnoremap <Esc>OE <nop>
Or use <C-v> to insert the keycode, that may or may not be terminal dependent.
The mapping isn't necessary in gVim, and may not be possible.
The reason why you see this behavior is that Vim uses only the termcap interface of the terminal database. If it used terminfo, it would see a wider range of information.
Typing the key on the keyboard is misleading, because Vim (like almost all terminal applications) puts the keypad into application mode, which causes the terminal to send Escape and O rather than Escape and [ as a prefix. In terminal notation, that is \EO. In XTerm Control Sequences, that is referred to as SS3 (technically a misnomer since that applies to output, while keyboard input is input — but since no standards apply to keyboard input, that's good enough).
The terminal description for xterm at one point assigned \EOE to the kbeg capability (i.e., terminfo, which termcap names #1). That was a while back, around 1996.
Terminfo names are generally 3-5 characters, while termcap names are always 2.
Standard terminfo has a limited number of special keys (such as those for the numeric keypad which you are familiar with). All of the standard termcap names correspond to these terminfo names. In the standard arrangement, there are only five keys associated with a keypad: ka1, ka3, kb2, kc1, and kc3, which correspond to termcap's K1, K2, K3, K4, and K5. (Why there are no standard k2, kb1, kb3, or kc2 is long forgotten).
Looking for ways to improve the terminal descriptions in ncurses, a few different layouts of the standard keys have been proposed. But the best solution lies in adding new keys, using extended capabilities (a feature of ncurses since 1999). Those extensions all have names, and are chosen to conform to terminfo naming conventions. So... in May 2019, the terminfo building blocks xterm+keypad and vt220+keypad were introduced. In the former (used in xterm-new and xterm-256color, that key is named kp5.
There's no kp5 in the standard names listed in the terminfo(5) manpage. It is an extended (user-definable) key. In the older scheme some other key was unavailable for applications.
An ncurses application would automatically be able to use all of the keys, because ncurses uses terminfo (and adds all of the keys in a terminal description to its special cases for timing).
Vim will not see that key's definition because it views only a fraction (about a third) of the terminal description. Since it does not see the definition, it does not add that to the special cases where it will wait (a short time) for the completion of the character-sequence sent on that key. As noted in the other answer, in that case, Vim will see the commands Escape and O to insert the third character in the sequence, "E".
Related
In Vim (or in a terminal?), control characters and their caret notation cannot be distinguished, like Enter vs. C-M. However, there is an only exception; BS vs. C-H.
Why are they only privileged?
For example, if you map Enter to NOP, also C-M will be mapped. Other many control characters have the same behavior. On the other hand, BS and C-H can be mapped to different keys respectively.
:map <Enter> <NOP> // also <C-M> will be mapped
:map <BS> <NOP> // only <BS> will be mapped, <C-H> won't
You can insert a backspace into a file by pressing controlV before the backspace. In that case, vim (and most editors) will display it as ^H. But normally backspace is treated as a command (telling vim to do something, depending on the mode).
When moving the cursor in a file containing control characters, you can readily distinguish between a control character versus caret next to another character: as you move the cursor left/right, vim will move two columns for the control character, but one column for each of the caret and other character.
I don't know all the nitty-gritty details, but basically (as I understand it) Vim uses an API to obtain the pressed keys that cannot distinguish between those different keys. For graphical applications like GVIM, all keys could be distinguished without problems; it's just a matter of switching to a more powerful (and GUI-only) API. For terminals, not all can actually distinguish between those keys (with <BS> / <C-H> the only exception). Many modern once can, though, it it again becomes a matter of switching to a more powerful API.
Some people (foremost Paul LeoNerd Evans) want to fix that (even for console Vim in terminals that support this), and have floated various proposals, cp. http://groups.google.com/group/vim_dev/browse_thread/thread/626e83fa4588b32a/bfbcb22f37a8a1f8
But as of today, no patches or volunteers have yet come forward, though many have expressed a desire to have this in a future Vim release.
More details on the problem
Due to the way that the keyboard input is handled internally, it unfortunately isn't generally possible today to distinguish certain keys, even in GVIM. Some key combinations, like Ctrl + non-alphabetic cannot be mapped, and Ctrl + letter vs. Ctrl + Shift + letter cannot be distinguished. (Unless your terminal sends a distinct termcap code for it, which most don't.) In insert or command-line mode, try typing the key combination. If nothing happens / is inserted, you cannot use that key combination. This also applies to <Tab> / <C-I>, <CR> / <C-M> / <Esc> / <C-[> etc. (Only exception is <BS> / <C-H>.) This is a known pain point, and the subject of various discussions on vim_dev and the #vim IRC channel.
This is because the XK_BackSpace keysym generally causes terminals to send ASCII DEL (0x7F), not ASCII BS (0x08, ^H). To balance things out, XK_Delete sends a sequence like \033[3~. Thus, unlike XK_Tab/^I, XK_BackSpace and ^H send completely different bytes.
Programs using the terminfo database can read the kbs and kdch1 capabilities to know what Backspace and Delete send, respectively. You can see your terminal's value with tput:
$ tput kbs | sed -n l
\177$
\177 is octal for ASCII DEL (see ascii(7)).
Another method is to check the termios(4) structure, which controls the “cooked mode” used by e.g. cat to read input (unlike bash or zsh). This is what Vim does in get_tty_info (src/os_unix.c), uh, after it checks termcap(5), compares backspace and delete, and, uh, maybe calls :fixdel? But you get the idea.
Recently I started to use & favor urxvt due to its vast amount of options and because of the transparency feature.
Unfortunately, some key mapping in Vim do not work in urxvt.
For example, I have mapped Ctrl + Up/Down and Shift + Up/Down to 5 respectively 10 lines up/down movement or Ctrl + Left/Right to 1 word left/right movement.
These movement commands do work without any problems in xterm, but they refuse to work in urxvt: they switch to insert mode and paste a, b, c or d as input into my vim.
Why does this happen?
I also use zsh as my shell and mapped Ctrl + Left/Right to move 1 word left/right in zsh: this also stopped working in urxvt (while still working in xterm).
How can I get urxvt to correctly map the keys?
From the description of the problem you probably overlooked the fact that key definitions in urxvt differ from xterm. Unless you specially configure urxvt, its special keys (cursor- and keypad-keys) send different escape sequences than xterm when you modify those with shift, control, alt.
You can either use the escape sequences which urxvt sends, or you could use the keysym feature to configure urxvt to send comparable escape sequences. This feature was introduced by rxvt, and extended with urxvt to allow you to specify the modifiers (shift, control, etc), which you might want to limit the keysym to apply on:
keysym.sym: string
Compile frills: Associate string with keysym sym. The intervening resource name keysym. cannot be omitted.
The format of sym is "(modifiers-)key", where modifiers can be any combination of ISOLevel3, AppKeypad, Control, NumLock, Shift, Meta, Lock, Mod1, Mod2, Mod3, Mod4, Mod5, and the abbreviated I, K, C, N, S, M, A, L, 1, 2, 3, 4, 5.
That "compile frills" is a hint that it's an optional feature. However most packagers appear to turn on all of its options (except where they conflict). So it's probably available to you.
There's an overview of the topic (of the escape sequences) in the ncurses FAQ How can I use shift- or control-modifiers? (vim incidentally doesn't use ncurses or the modifier information in the terminal database—it's a termcap application—but that's a different problem).
In vim, you can have:
set t_ku=^[OA
set t_kd=^[OB
set t_kr=^[OC
set t_kl=^[OD
(To get ^[OA you press ctrl-v then up )
I use urxvt too, because it is fast, I don't use the transparency feature. In urxvt you may want to set option keysym.sym: action read man page for more details.
suggestion
If you use vim, use vim motions, ctrl-U/D/F/B or wWeEbB... You don't need the arrow keys at all. E.g. On my keyboard, pressing arrow keys I have to press an extra Fn key.. too expensive, and my fingers have to leave the homerow.
In terminal, I suggest you getting used to emacs-binding to edit command line, your word jumping would be: alt-b (back) and alt-f(forward) There are a lot more, very common to use: ctrl-f, c-h, c-w, a-w,c-b,c-u,c-k,a-. etc ..... also man should not forget the c-xc-e
Vim/vi shortcuts are awesome, but there is one behavior that I would be very happy if it could be configured. My machine uses Brazilian Portuguese(abnt2) keyboard map,and some accents(like caret) needs an extra spacebar to be print, obviously because they wait/expect another character, mostly vowels. Example of the "cut until you find an empty line":
d/^$
Keystrokes actually needed on br-abnt2:
d / <shift + ~ , spacebar>(to result ^) $ <enter>
I could use { d } as it is explained on this awesome thread, but i would benefit much more on other accents(backslash) where the extra backspace trick is needed, and most important, without change my keyboard mapping to "US" for example.
Edit: I also know that this is a keymap limitation, since our language expect something after the accent, and this is why i'm asking if there is a way to circunvent this limitation inside vim.
Any ideas?
The problem does not come from the editor, but your keymap. In fact, the caret is set to be a "dead key". Meaning that it should wait for other input before being printed.
What you probably need is a new keymap that has the caret as a non dead-key. As for example, uk-gb map has caret on the key as well as another dead-key ( if I remember correctly).
If you don't want/can't remap your keyboard, you can use vim mapping function do act so.
Just choose an unused key and map it like this:
imap g ^
This will insert ^ while typing g on insert mode (other mapping for other- mode exists, nmap, ...).
For example, to use the vim mapping in the vim command-line, you shall use :
cmap g ^
Then your example will be working.
I've been trying out vim, and the emphasis on speed and accessibility makes sense for the veteran programmer. I've previously used emacs, and currently use a combination of nano, and stuff like gedit or geany.
I'm confused by the need to constantly switch modes, and that returning from insert mode to normal mode requires leaving the home row to press Esc. I've read that previously, this key was Tab on some systems where vim was first used, which makes a lot more sense, but not on current systems where tab is expected to participate in smart indenting when coding.
Returning to normal mode is an operation that you need to perform all the time. Is there some alternative key mapping that makes this quicker, or mappings that I simply don't know about that do this?
Ctrl+C also return you to normal mode
You can also use ^[. If you've mapped your caps lock key to control (highly recommended), this becomes a rather easy keystroke.
I personally use the Capslock key as the second Esc key, so it is very comfortable. You can do it by adding the following lines to your .xmodmap file:
remove Lock = Caps_Lock
keysym Caps_Lock = Escape
You can map whatever you like to escape:
imap kj <Esc>
I haven't yet run across a situation where I need to type kj next to each other, besides when I talk about this mapping. I've seen other people use jk or jj, but kj works best for me.
I personally use ii to get out of insert mode while staying on the home row, but it is only a matter of personal preference:
inoremap ii <Esc>
i to go in insert and ii to go out. This is easy for your finger to remember. (I tend to still use <Esc> though)
I personally use Left Control as escape and Caps Lock as Left Control. It is not vim mapping, but some xmodmap+setxkbmap magic:
! ~/.Xmodmap
! Control_R
keycode 37 = Escape
and ctrl:nocaps in X keyboard options. You may have different keycode though.
Use Alt/Meta In a Terminal
If you use Vim in a terminal, simply press alt/meta+normal_mode_key. Most terminals send an escape character followed by the normal_mode_key that you pressed, removing the need to press escape yourself.
The terminals konsole and gnome terminal send the escape by default when you press alt/meta+normal_mode_key. For Xterm you can ctrl+click and select the option "Meta sends escape" or "Alt sends escape".
Thus in insert mode pressing alt+h alt+j alt+k alt+l all take you to normal mode and move in the expected direction. You can hold down alt when moving even while in normal mode since the additional ESC that is sent does no harm.
The advantage of using this scheme is that you can use the alt/meta+key combination with any normal mode key, e.g.
Alt+o opens a new line below the one you are currently editing,
Alt+A appends to the end of the current line,
Alt+p pastes at the current insert location.
Alt+k moves up
Thus using vim via a terminal gives you these short cut powers on any stock standard system without the need to edit each systems vim mappings.
I'd like some map/remap/nmap/etc. commands to be case sensitive, e.g. "<C-I>" vs. "<C-i>".
I checked Google and :help map, but was unable to find this.
It appears you currently can't combine control with case-sensitivity in vim or gvim (I'm using 7.2). I might expect this to be a limitation of terminals for the former, but not the latter.
I tested it by typing this in a buffer:
map <c-i> :echo "c-i"<cr>
map <c-s-i> :echo "c-s-i"<cr>
Yank those lines, then :#" (when executes register " as commands). Verifying the maps with :map <c-i> and <c-s-i> shows the problem: <c-i> is <tab>, and only the last one takes effect, with the shift being ignored.
For alt, <a-i> and <a-s-i> do work as expected in gvim
In terminal vim, those two get mapped to é and É (at least here, check with ":map <a-i>" as above), and typing é/É directly (I use dead keys) does invoke the mapping. Actually doing a-i or a-s-i just enters insert mode.
Of course, non-control and non-alt maps work case-sensitively.
Add S for Shift
<C-S-i>
If you use your Caps Lock, (1) what on earth for?, and (2) you'll have problems. See here if this is your situation.
My bad.
Cannot be done, by design, with printable characters. The approach above does work with F1 et al, such as <C-S-F8>. See this thread for more.
My workaround would be to map it to something entirely different and obscure, and use AutoHotkey or similar to substitute the combination only for the uppercase variant.
Docs say that "CTRL-A and CTRL-a are equivalent".
Relevant part from :help notation
CTRL-{char} {char} typed as a control character; that is, typing {char}
while holding the CTRL key down. The case of {char} does not
matter; thus CTRL-A and CTRL-a are equivalent. But on some
terminals, using the SHIFT key will produce another code,
don't use it then.
(not intended as an answer, but as relevant info for anybody comming from search engine regarding case sensitivity)