编写脚本，接收两个位置参数，magedu和/www，判断系统是否有magedu，如果没有则自动创建magedu用户，并自动设置家目录为/www
[root@Centos7 scripts]# cat create_user.sh
#!/bin/bash
#
[ "$#" -eq 2 ] || { echo "Please enter two parameters: magedu /www" ; exit 1 ;}
if [ "$1" == "magedu" -a "$2" == "/www" ] || [ "$1" == "/www" -a "$2" == "magedu" ]; then
for i in $* ; do
if [ "$i" == "magedu" ]; then
USERNAME=$i
else
USERHOME=$i
fi
done
else
echo "Parameter must be magedu and /www ..."
exit 1
fi
if id ${USERNAME} &> /dev/null; then
echo "${USERNAME} is existed..."
else
useradd -d ${USERHOME} ${USERNAME}
echo "${USERNAME} is created..."
fi测试：
[root@Centos7 scripts]# ./create_user.sh
Please enter two parameters: magedu /www
[root@Centos7 scripts]# ./create_user.sh www magedu
Parameter must be magedu and /www ...
[root@Centos7 scripts]# ./create_user.sh www magedu www
Please enter two parameters: magedu /www
[root@Centos7 scripts]# ./create_user.sh /www magedu
magedu is created...
[root@Centos7 scripts]# ./create_user.sh /www magedu
magedu is existed...
[root@Centos7 scripts]# getent passwd magedu
magedu:x:1001:1001::/www:/bin/bash
[root@Centos7 scripts]# ll /www -d
drwx------ 3 magedu magedu 78 8月 10 11:27 /wwwexpect
expect是由Don Libes基于Tcl（Tool Command Language）语言开发的，主要应用于自动化交互式操作的场景，借助expect处理交互式的命令，可以将交互过程如：ssh登陆，ftp登陆等写在一个脚本上，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，可以大大提高系统管理人员的工作效率
示例：ssh连接192.168.2.121
先观察当前主机ssh连接121有什么特征
[root@centos7 scripts]# ssh 192.168.2.121
[email protected]'s password: #在ssh连接121时，需要输入密码，关键字是passwd 使用脚本实现自动登录并且还停留在121上
注意：
1、脚本后缀名.exp （约定俗成的，并非一定）
2、脚本开头是/usr/bin/expect (通过which expect查看路径)
[root@centos7 scripts]# which expect
/usr/bin/expect
[root@centos7 scripts]# vim expect_ssh.exp
[root@centos7 scripts]# cat expect_ssh.exp
#!/usr/bin/expect
#
set timeout 30
set host "192.168.2.121"
set username "root"
set password "123.com"
spawn ssh $username@$host
expect "password" {send "$password\r"} #\r是回车
#interact #当注释interact时，是不会停留在121机器上的
[root@centos7 scripts]# chmod +x expect_ssh.exp
[root@centos7 scripts]# ./expect_ssh.exp
spawn ssh [email protected]
[email protected]'s password: [root@centos7 scripts]# #直接返回到了测试机器终端上
[root@centos7 scripts]# vim expect_ssh.exp
[root@centos7 scripts]# cat expect_ssh.exp
#!/usr/bin/expect
#
set timeout 30 #设置超时时长，单位为秒，默认是10秒
set host "192.168.2.121" #设置变量host
set username "root" #设置变量username
set password "123.com" #设置变量password
spawn ssh $username@$host #spawn是进入expect环境后才才可以执行expect内部命令，如果没有装expect或直接在默认的shell下执行是找不到spawn命令的，主要功能就是给ssh运行进程加个壳，用来传递交互指令
expect "password" {send "$password\r"}
interact #开启interact，对比下效果；执行完成后保持交互状态，把控制权交给控制台，这个时候就可以手工操作了。如果没有这一句登录完成后会退出，而不是留在远程终端上
[root@centos7 scripts]# ./expect_ssh.exp
spawn ssh [email protected]
[email protected]'s password:
Last login: Sun Jun 21 13:48:37 2020 from centos7.lan
[root@Centos6 ~]# #这台centos6的机器就是192.168.2.121这就是对上述这段简单简单脚本的分析，在上述的示例中，涉及到expect中一个非常重要的概念——模式-动作；即上述expect "password" {send "$password\r"}这句代码表达出来的含义
刚那是已经有连接过121机器，所以会跳过指纹验证那块，接下来再来，把known_hosts删除，模拟一个全新的ssh连接。注意观察特征
[root@centos7 scripts]# rm ~root/.ssh/known_hosts
rm: remove regular file ‘/root/.ssh/known_hosts’? y
[root@centos7 scripts]# ssh 192.168.2.121 #蓝色表示特征，也就是需要匹配的值，粉红是需要手动输入的，当然password哪里也是需要输入手动密码
The authenticity of host '192.168.2.121 (192.168.2.121)' can't be established.
RSA key fingerprint is SHA256:oOQ2p3kF0ksYSimQxOywI9zkxFOx0JARw5aIkfO/eqQ.
RSA key fingerprint is MD5:6c:d9:39:01:d9:a5:16:68:b1:1e:c1:5f:7f:b5:fa:b3.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.2.121' (RSA) to the list of known hosts.
[email protected]'s password:
[root@centos7 scripts]# !rm
rm ~root/.ssh/known_hosts
rm: remove regular file ‘/root/.ssh/known_hosts’? y
[root@centos7 scripts]# vim expect_ssh2.exp
[root@centos7 scripts]# cat expect_ssh2.exp
#!/usr/bin/expect
#
set timeout 30
set host "192.168.2.121"
set username "root"
set password "123.com"
spawn ssh $username@$host
expect {
"yes/no" {send "yes\r"}
"password" {send "$password\r"}
}
interact
[root@centos7 scripts]# ./expect_ssh2.exp
spawn ssh [email protected]
The authenticity of host '192.168.2.121 (192.168.2.121)' can't be established.
RSA key fingerprint is SHA256:oOQ2p3kF0ksYSimQxOywI9zkxFOx0JARw5aIkfO/eqQ.
RSA key fingerprint is MD5:6c:d9:39:01:d9:a5:16:68:b1:1e:c1:5f:7f:b5:fa:b3.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.2.121' (RSA) to the list of known hosts.
[email protected]'s password: #停留在这里不动了，需要手动输入密码才行
#解决方法：增加exp_continue
[root@centos7 scripts]# vim expect_ssh2.exp
[root@centos7 scripts]# cat expect_ssh2.exp
#!/usr/bin/expect
#
set timeout 30
set host "192.168.2.121"
set username "root"
set password "123.com"
spawn ssh $username@$host
expect {
"yes/no" {send "yes\r"; exp_continue} #类似于while循环里的continue，当匹配到yes/no后，再次进行下次匹配，password，如果还有其它的匹配，那么需要增加exp_continue到倒数第二个匹配里
"password" {send "$password\r"}
}
interact
[root@centos7 scripts]# ./expect_ssh2.exp
spawn ssh [email protected]
The authenticity of host '192.168.2.121 (192.168.2.121)' can't be established.
RSA key fingerprint is SHA256:oOQ2p3kF0ksYSimQxOywI9zkxFOx0JARw5aIkfO/eqQ.
RSA key fingerprint is MD5:6c:d9:39:01:d9:a5:16:68:b1:1e:c1:5f:7f:b5:fa:b3.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.2.121' (RSA) to the list of known hosts.
[email protected]'s password:
Last login: Sun Jun 21 14:23:29 2020 from centos7.lan
[root@Centos6 ~]# ls
anaconda-ks.cfg install.log install.log.syslog
[root@centos7 scripts]# vim expect_ssh2.exp
[root@centos7 scripts]# cat expect_ssh2.exp
#!/usr/bin/expect
#
set timeout 30
set host "192.168.2.121"
set username "root"
set password "123.com"
spawn ssh $username@$host
expect {
"yes/no" {send "yes\r"; exp_continue}
"password" {send "$password\r"}
}
expect eof #等待执行结束，若没有这一句，可能导致命令还没执行，脚本就结束了
#interact
[root@centos7 scripts]# ./expect_ssh2.exp
spawn ssh [email protected]
The authenticity of host '192.168.2.121 (192.168.2.121)' can't be established.
RSA key fingerprint is SHA256:oOQ2p3kF0ksYSimQxOywI9zkxFOx0JARw5aIkfO/eqQ.
RSA key fingerprint is MD5:6c:d9:39:01:d9:a5:16:68:b1:1e:c1:5f:7f:b5:fa:b3.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.2.121' (RSA) to the list of known hosts.
[email protected]'s password:
Last login: Sun Jun 21 14:38:17 2020 from centos7.lan
[root@Centos6 ~]# ls #光标卡住不懂了，一直等待超时30秒，然后回到centos7，并且还执行了ls命令
[root@centos7 scripts]# ls
1.txt disk.sh ip2.sh outputKS.sh select7.sh trap_test.sh
2.txt d.txt ipaddr.sh pre.sh select8.sh user2.sh
99_2.sh dysjx.sh ip.sh print_action2.sh service_state2.sh useradd-1.sh
99.sh excute.sh links.sh print_action.sh service_state.sh useradd.sh
argsnum2.sh expect_ssh2.exp expect eof：等待执行结束，若没有这一句，可能导致命令还没执行，脚本就结束了
interact：执行完成后保持交互状态, 这时可以手动输入信息
注意：expect eof与interact二选一即可
接收参数
expect参数存在argv中，具体示例说明
[root@centos7 scripts]# vim expect_ssh3.exp
[root@centos7 scripts]# cat expect_ssh3.exp
#!/usr/bin/expect
#
set timeout 30
set host [lindex $argv 0]
set username [lindex $argv 1]
set password [lindex $argv 2]
if { $argc < 3} { #注意}{这两个之间是有空格的，而且在expect里，if条件时用大括号而非bash []或者其他语言的（）;$argc就是参数个数，相当于$#，可以如此记忆，arg是参数，后面的c表示count，个数的意思；$argv，后面的v表示value，值得意思
# puts "Usage:argv0 \n" #puts和send_user相同功能，类似bash shell中的echo -e
send_user "Usage:$argv0 \n" #$argv0是脚本名，但是[lindex $argv 0]是第一个参数，[lindex $argv 1]是第二个参数，依次类推；$argv0相当于bash位置变量的$0，[lindex $argv 1]相当于$1
exit
}
spawn ssh $username@$host
expect {
"yes/no" {send "yes\r"; exp_continue}
"password" {send "$password\r"}
}
interact
[root@centos7 scripts]# ./expect_ssh3.exp 192.168.2.121 root 123.com
spawn ssh [email protected]
The authenticity of host '192.168.2.121 (192.168.2.121)' can't be established.
RSA key fingerprint is SHA256:oOQ2p3kF0ksYSimQxOywI9zkxFOx0JARw5aIkfO/eqQ.
RSA key fingerprint is MD5:6c:d9:39:01:d9:a5:16:68:b1:1e:c1:5f:7f:b5:fa:b3.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.2.121' (RSA) to the list of known hosts.
[email protected]'s password:
Last login: Sun Jun 21 14:46:25 2020 from centos7.lan
[root@Centos6 ~]# ls
anaconda-ks.cfg install.log install.log.syslog 执行多个命令
结尾就不需要使用interact，而使用expect eof，毕竟不需要停留在对方终端上
这里通过“]#”来做匹配；创建kyle用户
[root@Centos6 ~]# getent passwd kyle
[root@Centos6 ~]#
[root@centos7 scripts]# vim expect_ssh4.exp
[root@centos7 scripts]# cat expect_ssh4.exp
#!/usr/bin/expect
#
set timeout 30
set host [lindex $argv 0]
set username [lindex $argv 1]
set password [lindex $argv 2]
if { $argc < 3} {
# puts "Usage:argv0 \n"
send_user "Usage:$argv0 \n"
exit
}
spawn ssh $username@$host
expect {
"yes/no" {send "yes\r"; exp_continue}
"password" {send "$password\r"}
}
expect "]#" {send "useradd kyle\r"}
expect "]#" {send "echo 123.com | passwd --stdin kyle\r"}
expect eof
[root@centos7 scripts]# ./expect_ssh4.exp 192.168.2.121 root 123.com
spawn ssh [email protected]
The authenticity of host '192.168.2.121 (192.168.2.121)' can't be established.
RSA key fingerprint is SHA256:oOQ2p3kF0ksYSimQxOywI9zkxFOx0JARw5aIkfO/eqQ.
RSA key fingerprint is MD5:6c:d9:39:01:d9:a5:16:68:b1:1e:c1:5f:7f:b5:fa:b3.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.2.121' (RSA) to the list of known hosts.
[email protected]'s password:
Last login: Sun Jun 21 14:46:33 2020 from centos7.lan
[root@Centos6 ~]# useradd kyle
[root@Centos6 ~]# echo 123.com | passwd --stdin kyle
Changing password for user kyle.
passwd: all authentication tokens updated successfully.
#切换到121机器上查看，因为之前写的脚本结束是expect eof，所以不能直接在121上操作。xshell连接到121上查看用户是否已经创建，其实上面红色标记已经显示很清楚已经创建了
[root@Centos6 ~]# getent passwd kyle #已经创建kyle用户，并且已经设置了密码
kyle:x:500:500::/home/kyle:/bin/bash
[root@Centos6 ~]# getent shadow kyle
kyle:$6$S.NY9Bt0$R2sVfsh7G3gLgviVt/cTZxWhoLRIfeJ.slX.j3z2OOS8kANN6g1YU6j.Wc3U6rX20kn70TjayN5jrgw3LfAeK.:18434:0:99999:7::: shell脚本调用expect
同样是上面脚本的改进，这次是增加kevin这个用户，并设置密码，同时也解决之前，执行完脚本后会停留在121终端上的问题
[root@Centos6 ~]# getent passwd kevin
[root@Centos6 ~]#
[root@centos7 scripts]# vim expect_ssh5.sh
[root@centos7 scripts]# cat expect_ssh5.sh
#!/bin/bash
#
host=$1
username=$2
password=$3
if [ "$#" -lt 3 ];then #与之前expect编写参数用法对照看
echo "Usage:$0 "
exit
fi
expect << EOF
spawn ssh $username@$host
expect { #注意，在shell调用expect脚本中大括号都需要空格，不像之前直接expect那样，不需要空格
"yes/no" { send "yes\r"; exp_continue }
"password" { send "$password\r" }
}
expect "]#" { send "useradd kevin\r" }
expect "]#" { send "echo 123.com | passwd --stdin kevin\r" }
expect "]#" { send "exit\r" } #增加这条expect后，就不需要再停留在121机器上了
expect eof
EOF
[root@centos7 scripts]# ./expect_ssh5.sh 192.168.2.121 root #能判断参数
Usage:./expect_ssh5.sh
[root@centos7 scripts]# ./expect_ssh5.sh 192.168.2.121 root 123.com #完全自动化操作，非人工输入
spawn ssh [email protected]
[email protected]'s password:
Last login: Sun Jun 21 15:26:47 2020 from centos7.lan
[root@Centos6 ~]# useradd kevin
[root@Centos6 ~]# echo 123.com | passwd --stdin kevin
Changing password for user kevin.
passwd: all authentication tokens updated successfully.
[root@Centos6 ~]# exit
logout
Connection to 192.168.2.121 closed.
[root@centos7 scripts]#
#验证结果如下
[root@Centos6 ~]# getent passwd kevin
kevin:x:502:502::/home/kevin:/bin/bash
[root@Centos6 ~]# getent shadow kevin
kevin:$6$iL5UNV/1$0ofohxfg8qUIM1Cxf8swxBqaZ2yyTVVdcw8.ynUNVe5Nhj/Dg3DDxTRWuEDnQd5IQ.Xyf.xHQQcdKC3eNCGeV1:18434:0:99999:7:::