How to sort lines by the right most characters?

Question

When I enter visual mode, :'<,'>sort allows me to sort alphabetically the lines I have selected, obviously starting from the left most characters on a line going to the right.

Is it possible to reverse this, so I sort alphabetically with the right most characters to the left?

Answer 1

If you can use the rev command, you could reverse each line, sort and reverse again, using external commands in a pipe:

%!rev | sort | rev

This can be done entirely in Vimscript, but it's way more verbose:

function! RTLSort() range
    " reversing function for use with map()
    function! Rev(k, str)
        " the first argument from map() is an index, so it's ignored.
        return join(reverse(split(a:str, '\zs')), '')
    endfunction
    let l:Rev = function("Rev")
    let l:lines = getline(a:firstline, a:lastline)
    call setline(a:firstline, map(sort(map(l:lines, l:Rev)), l:Rev))
endfunction

Then, something like:

:%call RTLSort()
:3,9 call RTLSort()