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