shell中expect介绍

expect介绍

借助Expect处理交互的命令,可以将交互过程如:ssh登录,ftp登录等写在一个脚本上,使之自动化完成.尤其适用于需要对多台服务器执行相同操作的环境中,可以大大提高系统管理人员的工作效率

expect安装

[root@ansible ssh]# rpm -qa | grep expect
expect-5.45-14.el7_1.x86_64
[root@ansible ssh]# yum install expect

expect 语法

expect [选项] [ -c cmds ] [ [ -[f|b] ] cmdfile ] [ args ]

选项

-c：从命令行执行expect脚本，默认expect是交互地执行的

示例：expect -c 'expect "\n" {send "pressed enter\n"}

-d：可以输出输出调试信息

示例：expect -d ssh.exp

expect中相关命令

spawn：启动新的进程

send：用于向进程发送字符串

expect：从进程接收字符串

interact：允许用户交互

exp_continue 匹配多个字符串在执行动作后加此命令

expect最常用的语法(tcl语言:模式-动作)

单一分支模式语法：

expect “hi” {send “You said hi\n"} 匹配到hi后,会输出“you said hi”，并换行

多分支模式语法:

expect "hi" { send "You said hi\n" } \ "hehe" { send “Hehe yourself\n" } \ "bye" { send “Good bye\n" }

匹配hi,hello,bye任意字符串时,执行相应输出.等同如下:

expect { "hi" { send "You said hi\n"} "hehe" { send "Hehe yourself\n"} "bye" { send “Good bye\n"} }

自动拷贝文件到远程主机

执行expect 不能以bash file 的方式来执行 (开启一个子shell进程)

必须通过 chmod +x file ./file 这样的方式 (不会开启子shell进程,只在当前shell环境中执行)

expect 如果只交互一次如拷贝文件结尾就使用 expect eof

如果需要连续交互如登录远程主机执行各种命令结尾就需使用 interact

.安装expect  系统默认没有此命令

   yum install expect

.创建配置文件

[root@ansible ssh]# vi hosts

192.168.31.134 root root

192.168.31.135 root root

192.168.31.136 root root

.编写脚本

[root@ansible ssh]# ls

copykey.sh  hosts

[root@ansible ssh]# vi copykey.sh

#!/bin/bash

if [ ! -f ~/.ssh/id_rsa ];then

 ssh-keygen -t rsa -P "" -f ~/.ssh/id_rsa

else

 echo "id_rsa has created ..."

fi

#分发到各个节点

while read line

  do

    user=`echo $line | cut -d " " -f `

    ip=`echo $line | cut -d " " -f `

    passwd=`echo $line | cut -d " " -f `

    expect <<EOF

      set timeout

      spawn ssh-copy-id $user@$ip

      expect {

        "yes/no" { send "yes\n";exp_continue }

        "password" { send "$passwd\n" }

      }

     expect "password" { send "$passwd\n" }

EOF

  done <  hosts

.给脚本执行权限

  chmod +x copykey.sh

.执行脚本

   ./copykey.sh

读取配置文件自动执行ssh

 #!/usr/bin/expect

 spawn scp /etc/fstab root@192.168.33.129:/root

 expect {

      "yes/no" { send "yes\n";exp_continue }

      "password" { send "root\n" }

 }

 expect eof

 [root@centos7 ~]# bash one.expect

 one.expect: line : spawn: command not found

 couldn't read file "{": no such file or directory

 one.expect: line : yes/no: No such file or directory

 one.expect: line : exp_continue: command not found

 one.expect: line : password: command not found

 one.expect: line : syntax error near unexpected token `}'

 one.expect: line : `}'

 [root@centos7 ~]# ./one.expect

 spawn scp /etc/fstab root@192.168.33.129:/root

 The authenticity of host '192.168.33.129 (192.168.33.129)' can't be established.

 RSA key fingerprint is SHA256:FzQU22CgZBnSbmZAuoypliidxPK9PsOFjJwcYUZWk5E.

 RSA key fingerprint is MD5:a8:2b::c3:dc:::::d2:d5:e0:9f:e9::1a.

 Are you sure you want to continue connecting (yes/no)? yes

 Warning: Permanently added '192.168.33.129' (RSA) to the list of known hosts.

 root@192.168.33.129's password:

 fstab

 #!/usr/bin/expect

   set ip [lindex $argv ]

   set user [lindex $argv ]

   set password [lindex $argv ]

   set timeout

   spawn ssh $user@$ip

    expect {

        "yes/no" { send "yes\n";exp_continue }

        "password" { send "$password\n" }

     }

    expect "]#" { send "useradd haha\n" }

    expect "]#" { send "echo aaa|passwd --stdin haha\n" }

    send "exit\n" expect eof

   #./ssh4.exp 192.168.8.100 root aa

执行多条命令

 #!/bin/bash

 ip=$

 user=$

 password=$

 expect <<EOF

     set timeout

     spawn ssh $user@$ip

     expect {

         "yes/no" { send "yes\n";exp_continue }

         "password" { send "$password\n" }

     }

     expect "]#" { send "useradd hehe\n" }

     expect "]#" { send "echo rrr|passwd --stdin hehe\n" }

     expect "]#" { send "exit\n" } expect eof

  EOF

  #./ssh5.sh 192.168.8.100 root aaa

shell调用expect