expect介紹

expect 是由 Don Libes 基于 Tcl（Tool Command Language）語言開發(fā)的，主要應(yīng)用于自動(dòng)化交互式操作的場景嫌褪，借助 Expect 處理交互的命令笼痛，可以將交互過程如：ssh登錄，ftp登錄等寫在一個(gè)腳本上摘刑，使之自動(dòng)化完成刻坊。尤其適用于需要對多臺(tái)服務(wù)器執(zhí)行相同操作的環(huán)境中谭胚，可以大大提高系統(tǒng)管理人員的工作效率。

expect 語法：

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

• 選項(xiàng)：
  ?-c：從命令行執(zhí)行 expect 腳本漏益，默認(rèn) expect 是交互地執(zhí)行的
  ??expect -c expect "\n" {send "pressed enter\n"}
  ?-d：可以輸出調(diào)試信息
  ??expect -d ssh.exp

• expect 中相關(guān)命令：
  ?spawn：啟動(dòng)新的進(jìn)程
  ?send：用于向進(jìn)程發(fā)送字符串
  ?expect：從進(jìn)程接收字符串
  ?interact：允許用戶交互
  ?exp_continue：匹配多個(gè)字符串在執(zhí)行動(dòng)作后加此命令

• expect 最常用的語法（tcl 語言：模式 - 動(dòng)作）

• 單一分支模式語法：
  匹配到 hi 后蛹锰，會(huì)輸出 "You said hi"，并換行

  [root@node2 ~]# expect
  expect1.1> expect "hi" {send "You said hi\n"}
  hi
  You said hi
  

• 多分支模式語法：
  匹配 hi绰疤，hehe铜犬，bye 任意字符串時(shí)，執(zhí)行相應(yīng)輸出

  [root@node2 ~]# expect
  expect1.1> expect "hi" { send "You said hi\n" } \
  +> "hehe" { send "Hehe yourself\n" } \
  +> "bye" { send "Good bye\n" }
  hi
  You said hi
  

  [root@node2 ~]# expect
  expect1.1> expect {
  +> "hi" { send "You said hi\n" }
  +> "hehe" { send "Hehe yourself\n" }  
  +> "bye" { send "Good bye\n" }
  +> }
  hi
  You said hi
  

示例：

1. 自動(dòng)化遠(yuǎn)程復(fù)制文件

   #!/usr/bin/expect
   spawn scp /etc/fstab 192.168.8.100:/app
   expect {
           "yes/no" { send "yes\n";exp_continue }
           "password" { send "RyoATeu6\n" }
   }
   expect eof
   

2. 自動(dòng)化登錄

   #!/usr/bin/expect
   spawn ssh 192.168.8.100
   expect {
           "yes/no" { send "yes\n";exp_continue }
           "password" { send "RyoATeu6\n" }
   }
   interact
   

3. 變量

   #!/usr/bin/expect
   set ip 192.168.8.100
   set user root
   set password 88888888
   set timeout 10
   spawn ssh $user@$ip
   expect {
           "yes/no" { send "yes\n";exp_continue }
           "password" { send "$password\n" }
   }
   interact
   

4. 位置參數(shù)

   #!/usr/bin/expect
   set ip [lindex $argv 0]
   set user [lindex $argv 1]
   set password [lindex $argv 2]
   spawn ssh $user@$ip
   expect {
           "yes/no" { send "yes\n";exp_continue }
           "password" { send "$password\n" }
   }
   interact
   

5. shell腳本調(diào)用expect

   #!/bin/bash
   ip=$1
   user=$2
   password=$3
   expect <<EOF
   set timeout 10
   spawn ssh $user@$ip
   expect {
           "yes/no" { send "yes\n";exp_continue }
           "password" { send "$password\n" }
   }
   expect "]#" { send "useradd hehe\n" }
   expect "]#" { send "echo 88888888 | passwd --stdin hehe\n" }
   expect "]#" { send "exit\n" }
   expect eof
   EOF