expect是一種能夠按照腳本內容裏面設定的方式與交互式程序進行“會話”的程序。根據腳本內容，Expect可以知道程序會提示或反饋什麼內容以及 什麼是正確的應答。它是一種可以提供“分支和嵌套結構”來引導程序流程的解釋型腳本語言。
shell功能很強大,但是不能實現有交互功能的多機器之前的操作,例如ssh和ftp.而expect可以幫助我們來實現。
一,安裝expect
yum install -y expect tcl
其實expect根bash形式上差不多的.
二,實例
1,ssh實現自動登錄,並停在登錄服務器上
#!/usr/bin/expect -f
set ip [lindex $argv 0 ] //接收第一個參數,並設置IP
set password [lindex $argv 1 ] //接收第二個參數,並設置密碼
set timeout 10 //設置超時時間
spawn ssh root@$ip //發送ssh請滶
expect { //返回信息匹配
"*yes/no" { send "yes\r"; exp_continue} //第一次ssh連接會提示yes/no,繼續
"*password:" { send "$password\r" } //出現密碼提示,發送密碼
}
interact //交互模式,用戶會停留在遠程服務器上面.運行結果如下:
root@ubuntu:/home/zhangy# ./test.exp 192.168.1.130 admin spawn ssh [email protected] Last login: Fri Sep 7 10:47:43 2012 from 192.168.1.142 [root@linux ~]#
這個例子有統一的接口,根據IP和密碼可以連接到不同的機器.如果你嫌輸入IP和密碼麻煩,看下面的例子
#!/usr/bin/expect -f
set ip 192.168.1.130
set password admin
set timeout 10
spawn ssh root@$ip
expect {
"*yes/no" { send "yes\r"; exp_continue}
"*password:" { send "$password\r" }
}
interact運行結果如下:
root@ubuntu:/home/zhangy# ./web.exp spawn ssh [email protected] Last login: Fri Sep 7 12:59:02 2012 from 192.168.1.142 [root@linux ~]#
2,ssh遠程登錄到服務器,並且執行命令,執行完後並退出
#!/usr/bin/expect -f
set ip 192.168.1.130
set password admin
set timeout 10
spawn ssh root@$ip
expect {
"*yes/no" { send "yes\r"; exp_continue}
"*password:" { send "$password\r" }
}
expect "#*"
send "pwd\r"
send "exit\r"
expect eof運行結果如下:
root@ubuntu:/home/zhangy# ./test3.exp spawn ssh [email protected] [email protected]'s password: Last login: Fri Sep 7 14:05:07 2012 from 116.246.27.90 [root@localhost ~]# pwd /root [root@localhost ~]# exit logout Connection to 192.168.1.130 closed.
3,遠程登錄到ftp,並且下載文件
#!/usr/bin/expect -f
set ip [lindex $argv 0 ]
set dir [lindex $argv 1 ]
set file [lindex $argv 2 ]
set timeout 10
spawn ftp $ip
expect "Name*"
send "zwh\r"
expect "Password:*"
send "zwh\r"
expect "ftp>*"
send "lcd $dir\r"
expect {
"*file" { send_user "local $_dir No such file or directory";send "quit\r" }
"*now*" { send "get $dir/$file $dir/$file\r"}
}
expect {
"*Failed" { send_user "remote $file No such file";send "quit\r" }
"*OK" { send_user "$file has been download\r";send "quit\r"}
}
expect eof運行結果如下:
root@ubuntu:/home/zhangy# ./test2.exp 192.168.1.130 /var/www/www aaa.html spawn ftp 192.168.1.130 Connected to 192.168.1.130. 220 (vsFTPd 2.0.5) Name (192.168.1.130:root): zwh 331 Please specify the password. Password: 230 Login successful. Remote system type is UNIX. Using binary mode to transfer files. ftp> lcd /var/www/www Local directory now /var/www/www ftp> get /var/www/www/aaa.html /var/www/www/aaa.html local: /var/www/www/aaa.html remote: /var/www/www/aaa.html 200 PORT command successful. Consider using PASV. 150 Opening BINARY mode data connection for /var/www/www/aaa.html (66 bytes). 226 File send OK. 66 bytes received in 0.00 secs (515.6 kB/s) quit aaa.html has been download 221 Goodbye.
原文鏈接:http://blog.51yip.com/linux/1462.html