crasn with setting &lines and &columns

crasn-lines-columns.vim

" $ vim -u NONE -g -S thisfile.vim

let s:RAND_MAX = 32767
let s:seed = 0
function! s:rand()
  let s:seed = s:seed * 214013 + 2531011
  return (s:seed < 0 ? s:seed - 0x80000000 : s:seed) / 0x10000 % 0x8000
endfunction
function! s:random()
  return s:rand() / (s:RAND_MAX * 1.0)
endfunction

" Return a random integer N such that a <= N <= b.
function s:randint(a, b)
  return float2nr(a:a + ((a:b - a:a + 1) * s:random()))
endfunction

while 1
  let &columns = s:randint(1, 1000)
  let &lines = s:randint(1, 1000)
endwhile