commit https://github.com/vim/vim/commit/426f3754223c8ff8a1bc51d6ba1eba11e8982ebc Author: Bram Moolenaar <Bram@vim.org> Date: Fri Nov 4 21:22:37 2016 +0100 patch 8.0.0060 Problem: When using an Ex command for 'keywordprg' it is escaped as with a shell command. (Romain Lafourcade) Solution: Escape for an Ex command. (closes https://github.com/vim/vim/issues/1175)

#!/bin/sh
#
# ref - Check spelling of the arguments
#
# Usage: ref word ..
#
# can be used for the K command of Vim
#
spell <<EOF
$*
EOF