#!/bin/sh

set -eu

if [ ! ${#} -eq 1 ]; then
  echo 'mksh takes one argument' 1>&2
  exit 1
elif [ -e "${1}" ]; then
  echo "${1} already exists" 1>&2
  exit 1
fi

echo '#!/bin/sh
set -eu

' > "${1}"

chmod u+x "${1}"

"${EDITOR}" "${1}"