Expect是一个我们常在shell交互时常用到的工具，它主要由expect-send组成。Expect是等待输出内容中的特定字符。然后由send发送特定的相应。Expect的工作流程类似于：小明和小红说：hello,小红发现小明说的是hello，然后就回复小明hi。然后小明说：你好，我是小明。小红发现小明说的是”你好，我是XX“，就回复”你好，我是小红“。
本文主要内容： 1.安装expect 2 expect的一些基本命令选项 3 expect脚本
1. 安装expect
1.1 yum 安装
yum安装就比较简单了，直接运行yum install expect就可以了.
yum install expect
1.2 源码安装
源码安装前我们需要安装unzip和gcc
yum install unzip gcc -y
源码安装我们需要下载两个源码包。tcl源码包和expect源码包。
下载tcl源码包
cd /tmp &&wget http://core.tcl.tk/tcl/zip/release/tcl.zip
下载expect源码包
wget https://jaist.dl.sourceforge.net/project/expect/Expect/5.45.3/expect5.45.3.tar.gz
我们需要先编译安装tcl，因为expect包依赖于tcl。
解压压缩包并编译安装tcl
unzip tcl.zip && cd ./tcl/unix
./configure && make && make install
解压压缩包并编译安装expect.
cd /tmp && tar -xzvf expect5.45.3.tar.gz && cd expect5.45.3/
./configure && make && make install
检查是否安装好(显示安装好的版本号就是已经安装好了)并创建软链接。
expect -v
[root@localhost shell]# expect -v
expect version 5.45.3
[root@localhost shell]# ln -s /usr/local/bin/expect /usr/bin/expect
2.expect常用的参数选项
2.1 使用 -c 选项：在命令行运行expect 脚本。
示例：
[root@localhost shell]# expect -c 'expect "hi expect" {send "hi shell
"}'
hi expect
hi shell
[root@localhost shell]#
解释下：这个的意思就是当我们输入了"hi expect"后，系统输出"hi shell"表示回应,在"hi shell"后加"
"是为了让显示更为直观。
注意一点就是我们在输入完"hi expect"后要按换行键才会出来"hi shell".
2.2 使用 -d 选项：显示调试信息。
示例脚本：
[root@localhost shell]# cat ssh.exp
#!/usr/bin/expect -d
set timeout 30
spawn ssh-copy-id 192.168.123.218
expect {
"*yes/no" {send "yes
"; exp_continue}
"password:" {send "123456
"}
}
expect eof
当我运行它的时候，显示的信息（主要信息是加粗字体）：
expect version 5.45
argv[0] = /usr/bin/expect argv[1] = -d argv[2] = ./ssh.exp
set argc 0
set argv0 "./ssh.exp"
set argv ""
executing commands from command file ./ssh.exp
spawn ssh-copy-id 192.168.123.218
parent: waiting for sync byte
parent: telling child to go ahead
parent: now unsynchronized from child
spawn: returns {130244}
expect: does "" (spawn_id exp6) match glob pattern "*yes/no"? no
"password:"? no
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
expect: does "/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
" (spawn_id exp6) match glob pattern "*yes/no"? no
"password:"? no
The authenticity of host '192.168.123.218 (192.168.123.218)' can't be established.
ECDSA key fingerprint is SHA256:Qh+4R5mpwlU6kK3bf0k53ngm+WpKKnfvL1ZJo+YM3ic.
ECDSA key fingerprint is MD5:d2:76:6d:33:17:e1:51:83:13:aa:10:ce:f7:1f:9f:32.
Are you sure you want to continue connecting (yes/no)?
expect: does "/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
The authenticity of host '192.168.123.218 (192.168.123.218)' can't be established.
ECDSA key fingerprint is SHA256:Qh+4R5mpwlU6kK3bf0k53ngm+WpKKnfvL1ZJo+YM3ic.
ECDSA key fingerprint is MD5:d2:76:6d:33:17:e1:51:83:13:aa:10:ce:f7:1f:9f:32.
Are you sure you want to continue connecting (yes/no)? " (spawn_id exp6) match glob pattern "*yes/no"? yes
expect: set expect_out(0,string) "/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
The authenticity of host '192.168.123.218 (192.168.123.218)' can't be established.
ECDSA key fingerprint is SHA256:Qh+4R5mpwlU6kK3bf0k53ngm+WpKKnfvL1ZJo+YM3ic.
ECDSA key fingerprint is MD5:d2:76:6d:33:17:e1:51:83:13:aa:10:ce:f7:1f:9f:32.
Are you sure you want to continue connecting (yes/no"
expect: set expect_out(spawn_id) "exp6"
expect: set expect_out(buffer) "/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
The authenticity of host '192.168.123.218 (192.168.123.218)' can't be established.
ECDSA key fingerprint is SHA256:Qh+4R5mpwlU6kK3bf0k53ngm+WpKKnfvL1ZJo+YM3ic.
ECDSA key fingerprint is MD5:d2:76:6d:33:17:e1:51:83:13:aa:10:ce:f7:1f:9f:32.
Are you sure you want to continue connecting (yes/no"
send: sending "yes
" to { exp6 }
expect: continuing expect
expect: does ")? " (spawn_id exp6) match glob pattern "*yes/no"? no
"password:"? no
yes
expect: does ")? yes
" (spawn_id exp6) match glob pattern "*yes/no"? no
"password:"? no
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
expect: does ")? yes
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
" (spawn_id exp6) match glob pattern "*yes/no"? no
"password:"? no
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
expect: does ")? yes
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
" (spawn_id exp6) match glob pattern "*yes/no"? no
"password:"? no
root@192.168.123.218's password:
expect: does ")? yes
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
root@192.168.123.218's password: " (spawn_id exp6) match glob pattern "*yes/no"? no
"password:"? yes
expect: set expect_out(0,string) "password:"
expect: set expect_out(spawn_id) "exp6"
expect: set expect_out(buffer) ")? yes
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
root@192.168.123.218's password:"
send: sending "123456
" to { exp6 }
Number of key(s) added: 1
Now try logging into the machine, with: "ssh '192.168.123.218'"
and check to make sure that only the key(s) you wanted were added.
expect: read eof
expect: set expect_out(spawn_id) "exp6"
expect: set expect_out(buffer) "
Number of key(s) added: 1
Now try logging into the machine, with: "ssh '192.168.123.218'"
and check to make sure that only the key(s) you wanted were added.
"
还有一些其他参数，但是我觉得对于我用处不大，所以没有在此记录。
3.expect脚本示例
简单在这记录下下面会用到的一些命令
set timeout #设置超时时间,默认超时时间10s.
spawn shell command # spawn后面接的是我们要执行的shell命令
expect "hi" #匹配输出内容“hi”
{send “hello
”} # 匹配到内容''hi"后输出“hello”，“
”是代表是返回字符。
interact #执行完成后保持交互状态，把控制权交给控制台，这个时候就可以手工操作了。如果没有这一句登录完成后会退出，而不是留在远程终端上。如果你只是登录过去执行一段命令就退出，可改为［expect eof］
3.1 简单更改密码脚本
[root@localhost shell]# cat password.exp
#!/usr/bin/expect -d #"#!/usr/bin/expect"这一行告诉操作系统脚本里的代码使用那一个shell来执行。 -d 启用调试模式(可加可不加)。
set timeout 30 #设置超时时间为30s
spawn passwd user5 #spawn是进入expect环境后才可以执行的expect内部命令，如果没有装expect或者直接在默认的SHELL下执行是找不到spawn命令的。所以不要用 “which spawn“之类的命令去找spawn命令。好比windows里的dir就是一个内部命令，这个命令由shell自带，你无法找到一个dir.com 或 dir.exe 的可执行文件。它主要的功能是给ssh运行进程加个壳，用来传递交互指令。
expect "New password:" {send "123456
" } #这个命令的意思是判断上次输出结果里是否包含“New password:”的字符串，如果有则立即返回"123456","
"代表是返回字符，否则就等待一段时间后返回，这里等待时长就是前面设置的30秒 。
expect "new password:" {send "123456
"} #在平常我们设置密码的时候会让我输入一次后再输入一次进行确认，这个是匹配第二次输出，然后再次输入密码。
expect eof #表示读取到文件结束符
3.2登陆远程服务器并停留在远程服务器上
[root@localhost shell]# cat login.exp
#!/usr/bin/expect
spawn ssh 192.168.123.218 #ssh 远程登陆
expect {
"*yes/no" {send "yes
";exp_continue} #匹配输出内容，返回内容，exp_continue表示继续执行下一步
"*password" {send "123456
"}
}
interact #执行完成后保持交互状态，把控制权交给控制台，这个时候就可以手工操作了。如果没有这一句登录完成后会退出，而不是留在远程终端上。如果你只是登录过去执行一段命令就退出，可改为［expect eof］
3.3传输参数执行登陆
[root@localhost shell]# cat login2.exp
#!/usr/bin/expect
set ip [lindex $argv 0] #这条命令是将变量ip的值设置为传入进来的第一个参数。[lindex $argv 0]表示的就是第一个参数的值
set port [lindex $argv 1] #这条命令是将变量port的值设置为传入进来的第二个参数。[lindex $argv 1]表示的就是第二个参数的值
set passwd "123456"
spawn ssh $ip -p$port #使用变量，这里使用的方法跟shell脚本一样
expect {
"yes/no" {send "yes
";exp_continue}
"password:" {send "$passwd
"}
}
interact
[root@localhost shell]# ./login2.exp 192.168.123.218 22 #多个参数直接以空格间隔，第一个参数：192.168.123.218 第二个参数22
3.4在shell脚本中使用expect
3.4.1通过添加expect脚本文件(建议这种)
实现的功能：输入ip（也就是我们传入的参数），并登陆到这个ip，并保持交互状态（interact）。
login.sh脚本内容（shell）
[root@localhost shell]# cat login.sh
#!/bin/bash
read -p "please input you ip:" -t30 remote_ip #获取登陆ip内容
echo "$remote_ip"
./login.exp $remote_ip #运行expect脚本 传入参数
login.exp脚本内容（expect）
[root@localhost shell]# cat login.exp
#!/usr/bin/expect
set ip [lindex $argv 0] #将参数值传递给变量ip
spawn ssh $ip #登陆ip
expect {
"*yes/no" {send "yes
";exp_continue} #匹配登陆信息，返回'yes'
"*password" {send "123456
"} #匹配输出信息，返回密码
}
interact #登陆成功后并保持交互状态，把控制权交给控制台
3.4.2在shell脚本直接写入expect命令
#!/bin/bash
read -p "please input you ip:" -t30 remote_ip #获取登陆ip内容
echo "$remote_ip"
expect -d <<EOF
spawn ssh $remote_ip
expect {
"*yes/no" {send "yes
";exp_continue}
"*password:" {send "Xuansiwei123!
"}
}
exit
expect eof;
EOF
3.4.3 expect匹配不同情况（有密钥文件则退出，没有则添加）
sshkey.exp #!/usr/bin/expect -d spawn ssh-keygen expect { ".ssh/id_rsa" {send " ";exp_continue} "Overwrite (y/n)?" exit #判断是否已经有密钥文件，有则退出，没有就进行添加。 "Enter passphrase" {send " ";exp_continue} "Enter same passphrase again:" {send " "} } expect eof
3.5批量分发公钥到远程主机
批量分发我主要有三个文件，第一个是ip.txt(用来储存ip和密码的，ip和密码直接以":"间隔，示例：192.168.123.12:123456),第二个文件是add.sh(包含读取ip.txt和批量添加的脚本)，第三个文件是 ssh_copy.exp（用来处理交互的脚本）
ip.txt文件内容
#ip password
192.168.123.110:123456
192.168.123.111:123@456!
这里注意下我第二行的ip的密码的最后一位是“!”,它在我shell脚本中的取出密码步骤也给我造成了一点麻烦，直接echo "$i"是报错的，我后面换成了echo "${i}",这样就不会报错了。
add.sh（shell脚本）
#!/bin/bash
IP_file='/root/shell/ip.txt'
if [ -e "$IP_file" ] #检查ip.txt文件是否存在，
then
echo -e " 33[1;32;40m IP file is exist 33[0m"
else
echo -e " 33[1;31;40m IP file is not exist 33[0m"
exit 2
fi
for i in $(cat ${IP_file})
do
IP=$(echo "${i}" |awk -F":" '{print $1}') #将ip.txt每行的ip值获取
PW=$(echo "${i}" |awk -F":" '{print $2}')#将ip.txt每行的ip值获取
./ssh_copy.exp $IP $PW
if [ $? -eq 0 ] #判断expect脚本是否执行成功
then
echo "$IP add is ok "
else
echo "$IP add faile"
fi
done
在上面的shell脚本我们还可以再加一个验证是否添加成功了，通过验证是否可以直接ssh登录来判断是否添加成功。
ssh_copy.exp（expect脚本）
#!/usr/bin/expect #调试的时候可以加个-d参数，便于查看我们的哪里步骤出现了错误。
set IP [lindex $argv 0 ]
set PW [lindex $argv 1 ]
spawn ssh-copy-id $IP
expect {
"yes/no" {send "yes
";exp_continue}
"password:" {send "$PW
"}
}
expect eof
这篇文章参考以下大佬的文章。
https://www.cnblogs.com/lixigang/articles/4849527.html
https://segmentfault.com/a/1190000002564816