#!/bin/zsh
# keep - poor man's version control, make freshly numbered copies

[[ $# = 0 ]] && exit 255

for f; do
  f=$f:A
  v=($f.<->(nOnN[1]))
  if [[ -n "$v" ]] && cmp $v $f >/dev/null 2>&1; then
    print -u2 $v not modified
  else
    cp -va $f $f.$((${${v:-.0}##*.} + 1))
  fi
done