sh-3.2# - root权限后的shell prompt

ShuaideMacBook-Pro:~ shuai$ su
Password:
sh-3.2# whoami
root
sh-3.2# exit // 退出root用户
exit
ShuaideMacBook-Pro:~ shuai$ whoami
shuai

" # normally indicates a root shell; $ normally indicates a non-root shell. 3.2 is the shell version. So sh-3.2$ is telling you that you don't have a root shell. (Typing whoami would also tell you that.) "