nのアレ

#!/bin/sh

INPUT_MESSAGE="exec ok?[Y/n] ";

# OK Cancel のアレ
while [ "${READ_KEY}" != "Y" ] && [ "${READ_KEY}" != "n" ]; do
    echo -n "${INPUT_MESSAGE}"
    read READ_KEY;
done;

# n だったら終了するよ
if [ "${READ_KEY}" = "n" ]; then
    exit 1;
fi

echo "なんか処理する"