rc/sh/e

#!/bin/zsh
# http://unix.stackexchange.com/a/37887
#[ -n "${ZSH_VERSION:-}" ] && local -A EDITOR ${=EDITOR}
# TODO: find actually working way of portably splitting word cmds, zsh/bash

if [ $# -eq 0 ]; then
  $=EDITOR
  return
fi

local f needroot=0
for f in $@; do
  [ -e "$f" ] && { [ -w "$f" ] || needroot=1; }
# TODO: check directory permissions too
done

if [ $needroot -eq 0 ]; then $=EDITOR $@; else sudo -e $@; fi