How to get visually selected text in VimScript

Question

I\'m able to get the cursor position with getpos(), but I want to retrieve the selected text within a line, that is \'<,\'>.

Answer 1

The best way I found was to paste the selection into a register:

function! lh#visual#selection()
  try
    let a_save = @a
    normal! gv"ay
    return @a
  finally
    let @a = a_save
  endtry
endfunction

Answer 2

I'm not totally sure about the context here, because getpos() can indeed accept marks (like '< and '>) as arguments.

However, to take a stab at what you might be asking for, there's also v, which is like '< except it's always updated (i.e. while the user is still in visual mode). This can be used in combination with ., the current cursor position, which will then represent the end of the visual selection.

Edit: I found these in :help line(); several functions including line() and getpos() have the same set of possible arguments.

Edit: I guess you're probably simply asking how to get the text between two arbitrary marks, not going line-by-line... (i.e. this doesn't specifically pertain to visual mode). I don't think there actually is a way. Yes, this seems like a pretty glaring omission. You should be able to fake it by finding the marks with getpos(), getting all the lines with getline(), then chopping off on the first and last according to the column position (with casework depending on whether or not it's multi-line). Sorry it's not a real answer, but at least you can wrap it up in a function and forget about it.

Answer 3

Overview:

visually select, press mapping, reselect original selection with gv and copy it to a register, finally paste from the register

Use case:

1. Add function Test() to your vimrc:

function! Test() range
exe 'sp temp.tmp'
exe 'norm p'
endfunction

2. Open a new file
3. Create the mapping ,m
   :vmap ,m :norm gvy<Esc>:call Test()<CR>
4. visually select some text
5. press ,m (the selection is gone, but 'norm gv' reselects it and 'y' yanks it to current register)
6. Test() is called: file temp.tmp is opened and 'norm p' pastes from current register, which is the original visual selection

Answer 4

Added block selection to @xolox's great answer: mode() isnt used cause it this is planned to be used in function whereby the selection has been cleared by calling the operator etc.

xnoremap <leader>a :<C-U> call GetVisualSelection(visualmode())<Cr>

function! GetVisualSelection(mode)
    " call with visualmode() as the argument
    let [line_start, column_start] = getpos("'<")[1:2]
    let [line_end, column_end]     = getpos("'>")[1:2]
    let lines = getline(line_start, line_end)
    if a:mode ==# 'v'
        " Must trim the end before the start, the beginning will shift left.
        let lines[-1] = lines[-1][: column_end - (&selection == 'inclusive' ? 1 : 2)]
        let lines[0] = lines[0][column_start - 1:]
    elseif  a:mode ==# 'V'
        " Line mode no need to trim start or end
    elseif  a:mode == "\<c-v>"
        " Block mode, trim every line
        let new_lines = []
        let i = 0
        for line in lines
            let lines[i] = line[column_start - 1: column_end - (&selection == 'inclusive' ? 1 : 2)]
            let i = i + 1
        endfor
    else
        return ''
    endif
    for line in lines
        echom line
    endfor
    return join(lines, "\n")
endfunction

Answer 5

I once wrote a function that is able to do it without touching registers or cursor position:

function s:F.map.getvrange(start, end)
    let [sline, scol]=a:start
    let [eline, ecol]=a:end
    let text=[]
    let ellcol=col([eline, '$'])
    let slinestr=getline(sline)
    if sline==eline
        if ecol>=ellcol
            call extend(text, [slinestr[(scol-1):], ""])
        else
            call add(text, slinestr[(scol-1):(ecol-1)])
        endif
    else
        call add(text, slinestr[(scol-1):])
        let elinestr=getline(eline)
        if (eline-sline)>1
            call extend(text, getline(sline+1, eline-1))
        endif
        if ecol<ellcol
            call add(text, elinestr[:(ecol-1)])
        else
            call extend(text, [elinestr, ""])
        endif
    endif
    return text
endfunction

It is called like this:

let [sline, scol, soff]=getpos("'<")[1:]
let [eline, ecol, eoff]=getpos("'>")[1:]
if sline>eline || (sline==eline && scol>ecol)
    let [sline, scol, eline, ecol]=[eline, ecol, sline, scol]
endif
let lchar=len(matchstr(getline(eline), '\%'.ecol.'c.'))
if lchar>1
    let ecol+=lchar-1
endif
let text=s:F.map.getvrange([sline, scol], [eline, ecol])

Note that at this point you will have a list of strings in text: one reason why I wrote this function is ability to keep NULLs in file. If you stick with any solution that yanks text in a register all NULLs will be replaced with newlines and all newlines will be represented as newlines as well. In the output of getvrange function though NULLs are represented as newlines while newlines are represented by different items: there is an NL between each list item, just like in output of getline(start, end).

This function can only be used to get lines for characterwise selection (as for linewise it is much simpler and for blockwise I iterate over lines and do not need such function. There are also functions for deleting given range (without touching registers) and inserting text at given position (without touching registers or cursor).

Answer 6

On Linux, there is a cheap but effective alternative to programming such a GetVisualSelection() function yourself: use the * register!

The * register contains the content of the most recent Visual selection. See :h x11-selection.

In your script you could then simply access @* to get the Visual selection.

let v = @*

Incidentally, * is also a neat little helper in interactive use. For example, in insert mode you can use CTRL-R * to insert what you had selected earlier. No explicit yanking involved.

This works only on operating systems that support the X11 selection mechanism.