How to fill a line with character x up to column y using Vim

Here's a function to implement what you ask, and slightly more.

• It fills the line from its current end of line, rather than the cursor position
• It forces a single space between what's currently on the line and the repeated chars
• It allows you to specify any string to fill the rest of the line with
• It uses vim's textwidth setting to decide how long the line should be (rather than just assuming 80 chars)

The function is defined as follows:

" fill rest of line with characters
function! FillLine( str )
    " set tw to the desired total length
    let tw = &textwidth
    if tw==0 | let tw = 80 | endif
    " strip trailing spaces first
    .s/[[:space:]]*$//
    " calculate total number of 'str's to insert
    let reps = (tw - col("$")) / len(a:str)
    " insert them, if there's room, removing trailing spaces (though forcing
    " there to be one)
    if reps > 0
        .s/$/\=(' '.repeat(a:str, reps))/
    endif
endfunction

Insert that into your .vimrc, and make a mapping to it, e.g.

map <F12> :call FillLine( '-' )

Then you can press F12 to apply the hyphens to the current line

Note: this could probably be easily extended to act on a selection in VISUAL mode, but currently works for single lines only.*

You can do 80Ax<Esc>d80| for a simpler solution.

If I understand the question correctly, this can be accomplished like this: in normal mode subtract the cursor's current column position from the desired ending column, then type the result followed by 'i' to enter insert mode, then the character you want to fill the space with. End by returning to normal mode. For example, with the cursor at column four in normal mode, if you wanted to fill the rest of the line up to column 80 with dashes, type 76i- then Esc or Ctrl-[ to return to normal mode. This should result in 76 dashes starting in column 4 and ending in column 79.

If you have the virtualedit option set to block or all, you can create a visual selection (even over empty space) up to the desired column:
v80| (if virtualedit=all) or
<c-v>80| (if virtualedit=block)

Then replace the selected area with dashes: r-

It's probably helpful to start visual mode after the last character in the line by hitting l to avoid overwriting the last character in the line. If you are not using virtualedit=all, then you need to set virtualedit+=onemore so you can move one character beyond the end of line in normal mode.