[root@host ~]# echo $SHELL /bin/bash当前Linux里有哪些shell？
[root@host ~]# cat /etc/shells /bin/sh /bin/bash /usr/bin/sh /usr/bin/bash切换到sh这个shell
#临时切换 [root@host ~]# sh sh-4.2# bash在/lianxi目录下新建china 文件夹，里面新建guangdong和zhejiang文件夹，guangdong下面有guangzhou，zhejiang下面有hangzhou
[root@host lianxi]# mkdir china/{guangdong/guangzhou,zhejiang/huangzhou} -p
