VIM: set term=xterm changes <BS> to <Del>, is it reversible? - vim

I have added set term=xterm to my vimrc to be able to use 256-color vim schemes in terminal, but it comes at a price (at least for me). It also replaces (sort of) the BackSpace with Delete (i.e. BackSpace starts to delete forward just like Delete does) in insert mode and makes it "BackSpace" instead of moving left (or h) in normal mode. I have nothing against Ctrl-H as a way "to Backspace", but I simply don't want to have two delete buttons and ability "to BackSpace" (delete backward) in normal mode.
How can I reverse that change while retaining the setting I need?
PS I've read :h CTRL-h and a bit of :h xterm, but I couldn't find the solution.

Vim's inoremap and nnoremap commands can be used to adjust how keys are interpreted in Vim.
A solution is documented here for your specific context: https://conemu.github.io/en/VimXterm.html
The relevant quote:
"If you have problems with BS in Vim (BS acts like Delete key) under ConEmu when term=xterm, you may try to remap BS key:
inoremap <Char-0x07F> <BS>
nnoremap <Char-0x07F> <BS>
"
In general, when a key does not do what you want, the trick is to find out what it actually sends to Vim. Sometimes hitting Ctrl-V followed by that key in insert mode might help figure it out. Then inoremap and nnoremap as shown above can be used to reassign it to the behaviour you want in insert and normal modes, respectively.

Related

why is `ctrl -h` not work in insert mode?(version gvim 8.1.1)

In "Practical Vim" (second edition), the writer says <c-h> can delete back a character. I've tried in git bash, and it worked. However, it doesn't work in gvim in win10 as expected.
When I enter something in insert mode, I can use <c-h>, <c-w> and <c-u> before I leave insert mode. When I switch to insert mode without entering anything, <c-h>, <c-w> and <c-u> don't work.
Note that <c-h> is not mapped (:map <c-h> prints No mapping found).
Vim, by default, does only allow to delete characters that you typed since you entered insert mode. It does not allow to delete chars before the point where you started inserting. This behavior is inherited from the original Vi.
To change that, Vim has the option 'backspace'. It configures how <Backspace>, <Del>, <c-w> and <c-u> work. Add the following to your _vimrc and Vim will behave as you expect:
set backspace=indent,eol,start
Then you can backspace over autoindent, start of insert and end-of-lines.
See :help 'backspace'.

Setting mouse=a and mapping <esc> to :noh breaks mouse working on vim? [duplicate]

I am a happy VIM user, although I admit I'm quite far from being fluent. I found this nice post:
Vim clear last search highlighting and I thought I'd become a better person if I didn't have to hammer away a random character sequence every time I did a search. Now, I'm also using the vimrc config from here:
http://amix.dk/vim/vimrc.html
and the problem I have is that when I add the line nnoremap <esc> :noh<return><esc> to it (it doesn't seem to make a difference where I put it) I get awkward behaviour when I use arrows in command mode, namely letters from A to D appear in a newline and I get switched to insert mode.
There has to be some mapping conflict but for the life of me I can't figure out where it is.
EDIT: As it follows from the answers it turns out the Ultimate vimrc part is not relevant, the mentioned nnoremap command will cause altered arrow behaviour even if it's the only vimrc entry. Changing title to a more informative one.
PS. I know I shouldn't use arrows, hopefully I'll get there one day.
The mapping
nnoremap <esc> :noh<return><esc>
will conflict with so called "grey keys" and I believe that it should be used either in GVim only or in terminal Vim by someone who does not use special keys like arrows.
From what I know (and guess) how Vim processes keys, I would say that it's impossible to do anything with this. For Vim to recognize special key all its components should go in a row, so when you press Arrow Left Vim gets the following sequence of codes:
<esc> [ D
But after your mapping Arrow Left becomes:
: n o h l <cr> <esc>
[ D
Vim sees two separate sequences and treats <esc> as a single press of Escape key, thus next two codes of Left Arrow key lose their special meaning.
So I suggest you to map :noh to some other key sequence (e.g. to one starting with <leader>, see :help mapleader; I don't recommend you to use F-keys, using them is as bad as using of arrow keys).
The cause had been explained well, but solution was not mentioned. However there is a straight one.
If you’ll tell to Vim explicitly that there are key sequences starting from <esc>[
:nnoremap <silent><esc> :noh<CR>
:nnoremap <esc>[ <esc>[
than when single <esc> will be pressed Vim will wait for a second (or different time, see :h 'timeoutlen') or for a next key (second <esc> for example) and only then replace it with :noh<CR>.
This solution preserves the ESC mapping to :nohlsearch.
The comment on this answer explaining why this is happening tells us that the root cause is the TermResponse behavior of vim. This can be compensated for by wrapping the mapping in an autocommand for the TermResponse event.
This ensures that the binding doesn't happen until after the term response is set, which prevents Esc from also sending a string like ]>1;3201;0c to vim.
Change your line in vimrc to this:
augroup no_highlight
autocmd TermResponse * nnoremap <esc> :noh<return><esc>
augroup END
The augroup commands are not strictly necessary, but they prevent multiple mappings when you reload your vimrc without quitting vim.
EDIT: If you also use a graphical vim like Gvim or Macvim, the TermResponse event will not fire. Assuming you use a single vimrc, you'll need some additional code like
if has('gui_running')
nnoremap <silent> <esc> :nohlsearch<return><esc>
else
" code from above
augroup no_highlight
autocmd TermResponse * nnoremap <esc> :noh<return><esc>
augroup END
end
Problem is that when you press an arrow terminal emits something like <Esc>OA. Vim part that supports terminal seems to use the same mapping mechanism to do the job as you are using: while nmap <Esc>OA will tell you nothing, call feedkeys("\eOA") will move one line up and call feedkeys("\eOA", 'n') will add letter A beyond current line. With your mapping being noremappable you forbid vim to use <Esc> as a part of the key. The problem is that you need remappable mapping here, but can have remappable mapping without it being recursive as well only if it starts with {lhs}, but <Esc>:noh<CR>OA is not going to work. I thought the following code will (it uses <expr> and function with side effect to make <Esc> be the first character of the actual {rhs} and still launch :noh), but in fact it does not:
function s:NoHlSearch()
nohlsearch
return "\e"
endfunction
nmap <expr> <Esc> <SID>NoHlSearch()
. I have no other idea how to solve the problem of having non-recursive remappable mapping which includes {lhs} but not at the start.
I have had good luck with this
if $TERM =~ 'xterm'
set noek
endif
nnoremap <silent> <esc> <esc>:noh<cr>
The disadvantage is that function keys can not be used in insert mode.
:h ek

Can't map Home button in vimrc

I want to map the Home button so vim goes to the first non blank character in vim. But mapping the home button doesn't do anything? If I map another key, then it works correctly.
See below my vimrc file:
map <Home> 0w
imap <Home> <ESC>0wi
The above doesn't work. While the following works (Ctrl-F for example)
map <C-f> 0w
imap <C-f> <ESC>0wi
Isn't there a way to map Home key to this? I really need it, because I got used to this when working with Notepad++, Sublime text 2, Visual Studio,...
I also tried the following, with no results. When using another key, it works again...
http://vim.wikia.com/wiki/Smart_home
From Vim FAQ (also available through this nice plugin):
20.4. I am not able to create a mapping for the <xxx> key. What is wrong?
1) First make sure, the key is passed correctly to Vim. To determine if
this is the case, put Vim in Insert mode and then hit Ctrl-V (or
Ctrl-Q if your Ctrl-V is remapped to the paste operation (e.g. on
Windows if you are using the mswin.vim script file) followed by your
key.
If nothing appears in the buffer (and assuming that you have
'showcmd' on, ^V remains displayed near the bottom right of the Vim
screen), then Vim doesn't get your key correctly and there is nothing
to be done, other than selecting a different key for your mapping or
using GVim, which should recognise the key correctly.
This way you can check if the home key you are pressing is the same that Vim understand as <Home>.
Another possibility is that some other mapping is interfering with this one. You could try the following:
noremap <Home> 0w
inoremap <Home> <ESC>0wi
Edit:
It seems the problem is that your terminal is sending a home keycode that Vim isn't recognizing as <Home>.
I believe that the best solution is make Vim recognize that key correctly, so you can move your .vimrc to other terminals/systems without changes.
From :h xterm-end-home-keys:
On some systems (at least on FreeBSD with XFree86 3.1.2) the codes that the
<End> and <Home> keys send contain a <Nul> character. To make these keys send
the proper key code, add these lines to your ~/.Xdefaults file:
*VT100.Translations: #override \n\
<Key>Home: string("0x1b") string("[7~") \n\
<Key>End: string("0x1b") string("[8~")
If that doesn't work, you could try :set t_kh=^V^[[1~. If it work you can enclose it on a check of your terminal type.
Additional information can be found at :h terminal options
Edit 2:
20.4. I am not able to create a mapping for the <xxx> key. What is wrong?
:
:
3) If the key is seen, but not as itself and not as some recognizable
key, then there is probably an error in the terminal library for the
current terminal (termcap or terminfo database). In that case >
:set term?
will tell you which termcap or terminfo Vim is using. You can try to
tell vim, what termcode to use in that terminal, by adding the
following to your vimrc: >
if &term == <termname>
set <C-Right>=<keycode>
endif
where <termname> above should be replaced by the value of 'term'
(with quotes around it) and <keycode> by what you get when hitting
Ctrl-V followed by Ctrl-Right in Insert mode (with nothing around
it). <C-Right> should be left as-is (9 characters). Don't forget that
in a :set command, white space is not allowed between the equal sign
and the value, and any space, double quote, vertical bar or backslash
present as part of the value must be backslash-escaped.
Now you should be able to see the keycode corresponding to the key
and you can create a mapping for the key using the following command: >
:map <C-Right> <your_command_to_be_mapped>
For more information, read
:h map-keys-fails
:h map-special-keys
:h key-codes

Mapping <esc> in vimrc causes bizarre arrow behaviour

I am a happy VIM user, although I admit I'm quite far from being fluent. I found this nice post:
Vim clear last search highlighting and I thought I'd become a better person if I didn't have to hammer away a random character sequence every time I did a search. Now, I'm also using the vimrc config from here:
http://amix.dk/vim/vimrc.html
and the problem I have is that when I add the line nnoremap <esc> :noh<return><esc> to it (it doesn't seem to make a difference where I put it) I get awkward behaviour when I use arrows in command mode, namely letters from A to D appear in a newline and I get switched to insert mode.
There has to be some mapping conflict but for the life of me I can't figure out where it is.
EDIT: As it follows from the answers it turns out the Ultimate vimrc part is not relevant, the mentioned nnoremap command will cause altered arrow behaviour even if it's the only vimrc entry. Changing title to a more informative one.
PS. I know I shouldn't use arrows, hopefully I'll get there one day.
The mapping
nnoremap <esc> :noh<return><esc>
will conflict with so called "grey keys" and I believe that it should be used either in GVim only or in terminal Vim by someone who does not use special keys like arrows.
From what I know (and guess) how Vim processes keys, I would say that it's impossible to do anything with this. For Vim to recognize special key all its components should go in a row, so when you press Arrow Left Vim gets the following sequence of codes:
<esc> [ D
But after your mapping Arrow Left becomes:
: n o h l <cr> <esc>
[ D
Vim sees two separate sequences and treats <esc> as a single press of Escape key, thus next two codes of Left Arrow key lose their special meaning.
So I suggest you to map :noh to some other key sequence (e.g. to one starting with <leader>, see :help mapleader; I don't recommend you to use F-keys, using them is as bad as using of arrow keys).
The cause had been explained well, but solution was not mentioned. However there is a straight one.
If you’ll tell to Vim explicitly that there are key sequences starting from <esc>[
:nnoremap <silent><esc> :noh<CR>
:nnoremap <esc>[ <esc>[
than when single <esc> will be pressed Vim will wait for a second (or different time, see :h 'timeoutlen') or for a next key (second <esc> for example) and only then replace it with :noh<CR>.
This solution preserves the ESC mapping to :nohlsearch.
The comment on this answer explaining why this is happening tells us that the root cause is the TermResponse behavior of vim. This can be compensated for by wrapping the mapping in an autocommand for the TermResponse event.
This ensures that the binding doesn't happen until after the term response is set, which prevents Esc from also sending a string like ]>1;3201;0c to vim.
Change your line in vimrc to this:
augroup no_highlight
autocmd TermResponse * nnoremap <esc> :noh<return><esc>
augroup END
The augroup commands are not strictly necessary, but they prevent multiple mappings when you reload your vimrc without quitting vim.
EDIT: If you also use a graphical vim like Gvim or Macvim, the TermResponse event will not fire. Assuming you use a single vimrc, you'll need some additional code like
if has('gui_running')
nnoremap <silent> <esc> :nohlsearch<return><esc>
else
" code from above
augroup no_highlight
autocmd TermResponse * nnoremap <esc> :noh<return><esc>
augroup END
end
Problem is that when you press an arrow terminal emits something like <Esc>OA. Vim part that supports terminal seems to use the same mapping mechanism to do the job as you are using: while nmap <Esc>OA will tell you nothing, call feedkeys("\eOA") will move one line up and call feedkeys("\eOA", 'n') will add letter A beyond current line. With your mapping being noremappable you forbid vim to use <Esc> as a part of the key. The problem is that you need remappable mapping here, but can have remappable mapping without it being recursive as well only if it starts with {lhs}, but <Esc>:noh<CR>OA is not going to work. I thought the following code will (it uses <expr> and function with side effect to make <Esc> be the first character of the actual {rhs} and still launch :noh), but in fact it does not:
function s:NoHlSearch()
nohlsearch
return "\e"
endfunction
nmap <expr> <Esc> <SID>NoHlSearch()
. I have no other idea how to solve the problem of having non-recursive remappable mapping which includes {lhs} but not at the start.
I have had good luck with this
if $TERM =~ 'xterm'
set noek
endif
nnoremap <silent> <esc> <esc>:noh<cr>
The disadvantage is that function keys can not be used in insert mode.
:h ek

How do I get Ctrl-Backspace to delete a word in vim within gnome-terminal?

I'd like Ctrl-Backspace to delete the current word in vim insert mode. From within xterm I can pull this off via
:inoremap <C-H> <C-W>
but in gnome-terminal I cannot figure out a way to make it happen.
When in vim insert mode, if I type control-v and then press backspace, I get ^H in xterm, and ^? in gnome-terminal. Unfortunately,
:inoremap <C-?> <C-W>
doesn't do the trick in gnome-terminal; control-backspace just erases a single character no matter what.
Regarding ASCII codes:
Gnome-terminal lets you change the backspace character under Edit -> Profile Preferences -> Compatibility. Unfortunately, no option works, as far as I can tell: whatever character I apply to Backspace via the settings, if I try mapping the character itself, like
:inoremap <C-H> <C-W>
then regular backspace and control-backspace both erase an entire word; and if I try mapping control plus that character, like
:inoremap <C-^H> <C-W>
then regular backspace and control-backspace just erase a single character.
gnome-terminal's libvte would need to be patched.
libvte already has several options to map backspace, none of which distinguish Ctrl-backspace. It needs an option that does, maybe one that follows the behaviour of the linux console (^? for backspace, ^H for Ctrl-backspace). See this gnome bug.
2015 update: this was fixed in 23c7cd0f99d504cbab06d4c27254d4f3e2807ba8.
libvte 0.41.90, 0.40.3 and newer have the fix.

Resources