[~]#echo "Hello world.\nHello sea" Hello world.\nHello sea [~]#echo -e "Hello world.\nHello sea" Hello world. Hello sea [~]#
参考：
https://blog.csdn.net/u013425438/article/details/80389176
shell中echo输出换行的方法
原文：https://www.cnblogs.com/sea-stream/p/11977334.html
