如何在linux shell脚本中自动输入密码.

迈不过友情╰ 2022-05-25 13:41 1305阅读 0赞

答案是需要通过expect 来实现。

【注意】如果没有 expect ，需要预先安装

\[tony@pd2 ~\]$ yum info expect  
Loaded plugins: fastestmirror  
Repodata is over 2 weeks old. Install yum-cron? Or run: **yum makecache fast**  
Loading mirror speeds from cached hostfile  
Available Packages  
Name : expect  
Arch : x86\_64  
Version : 5.45  
Release : 14.el7\_1  
Size : 262 k  
Repo : base/7/x86\_64  
Summary : A program-script interaction and testing utility  
URL : http://expect.nist.gov/  
License : Public Domain  
Description : Expect is a tcl application for automating and testing  
: interactive applications such as telnet, ftp, passwd, fsck,  
: rlogin, tip, etc. Expect makes it easy for a script to  
: control another program and interact with it.  
:  
: This package contains expect and some scripts that use it.  
  
\[tony@pd2 ~\]$ whereis expect  
expect:  
\[tony@pd2 ~\]$  
  
\# 必须以root用户安装 expect  
\[root@pd2 tony\]\# whereis expect  
\[root@pd2 tony\]\# yum install -y expect  
  
\[root@pd2 kevin\]\# whereis expect  
expect: /usr/bin/expect /usr/share/man/man1/expect.1.gz  
  
\-----------  
\# 写一个自动输入密码的脚本  
\[tony@pd2 ~\]$ cat change2kevin  
\#!/usr/bin/expect  
\# 不论是在此脚本内自动输入密码还是在脚本外手工输入密码，至少要等待1秒  
set timeout 1  
  
\# spawn将开启一个新的进程，也可以是ssh $user@$host \{your\_command\}  
\# 只有先进入expect环境后才可执行spawn  
spawn su kevin  
  
\# 判断上述进程(su kevin)的输出结果中是否有“password”的字符串(不区分大小写)。  
\# 若有则立即返回，否则就等待一段时间后返回，等待时长就是开头设置的1秒  
expect "\*password:"  
\# 向上面的进程(su kevin)发送字符串中的密码, 并且自动敲Enter健(\\r)  
send "kevin123456\\r"  
interact

\---------------

\# 验证一下, 从当前的 tony 用户切换到 kevin用户  
\[tony@pd2 ~\]$ ./change2kevin  
spawn su kevin  
Password:  
\[kevin@pd2 kevin\]$

成功切换用户！

另外，如果临时需要从本地通过ssh登录到远程机器的需求，也可以写一个类似的脚本：

\[tony@pd2 ~\]$ cat to\_pd4.sh

\#!/usr/bin/expect  
set timeout 1  
spawn ssh tony@pd4  
send "yes\\r"  
expect "\*password:"  
send "hello\\r"  
interact

\[tony@pd2 ~\]$ ./to\_pd4.sh \# 测试一下  
spawn ssh tony@pd4  
yes  
tony@pd4's password:  
Last login: Thu Apr 9 17:45:41 2020 from bd01  
\[tony@pd4 ~\]$

从结果可知，无需手动输入ssh密码，成功登入远程机器 ^\_^

【扩展】如何实现“输入用户名kevin，则自动切换到用户kevin？”

\[tony@pd2 ~\]$ vim ~/.bashrc \# 编辑当前用户的bashrc脚本，在里面添加一行：alias kevin="./change2kevin"

\[tony@pd2 ~\]$ grep "alias kevin=" ~/.bashrc

alias kevin="./change2kevin"

\[tony@pd2 ~\]$ source ~/.bashrc  
\[tony@pd2 ~\]$ kevin  \# 直接使用刚才在bashrc中自定义的别名kevin，就能切换到kevin用户  
spawn su kevin  
Password:  
\[kevin@pd2 liangpeng\]$ whoami

kevin

好了，就写到这里，看官们觉得涨知识了，请为本文点个赞 ^\_^