今天查问题时， ssh 登录后台发现 需要输入密码，输入密码后弹出一个二维码， 然后扫码获取秘钥。输入秘钥登陆！！！

真是恶心了一把，找手机都花了不少时间！！！！

　　那么怎样干掉输入密码这些操作呢？？？

所以需要思考一番！！！！

man 文档中有 When  bash is invoked as an interactive login shell, or as a non-inter‐ active shell with the --login option, it first reads and executes  com‐mands  from  the file /etc/profile, if that file exists.  After reading that file, it looks for ~/.bash_profile, ~/.bash_login, and ~/.profile,in  that order, and reads and executes commands from the first one that exists and is readable.  The --noprofile option may be  used  when  the  shell is started to inhibit this behavior. When  a  login  shell  exits, bash reads and executes commands from the files ~/.bash_logout and /etc/bash.bash_logout, if the files exists.When an interactive shell that is not a login shell  is  started,  bash reads  and executes commands from ~/.bashrc, if that file exists.  This may be inhibited by using the --norc option.  The --rcfile file  option will  force  bash  to  read  and  execute commands from file instead of ~/.bashrc.
意思是啥呢？？