#!/usr/bin/env zsh

SHUF=$(which shuf)
if [[ $? -ne 0 ]]; then
  SHUF=$(which gshuf)
  if [[ $? -ne 0 ]]; then
    echo "no `shuf` found, exiting"
    exit
  fi
fi

F=$(mktemp /tmp/bishuf.XXXXXX)
echo 42 > $F
$SHUF --random-source=$F $1 > $1.shuf
$SHUF --random-source=$F $2 > $2.shuf
rm $F