文章目录
Linux云计算架构-shell入门到精通(放弃)[3]
1. expect 实现无交互登录
# 安装expect
[root@client ~]# yum install expect -y
[root@client ~]# which expect
/usr/bin/expect
# 定义脚本执行的shell,即expect可执行文件的链接路径
#!/usr/bin/expect
# 设置超时时间
set timeout 30
set timeout -1
# 设置变量
set name "abong"
set passwd "123456"
# spawn命令，功能是给ssh进程加个壳，用来传递交互指令。【交互式输入的首条命令】
# expect命令，判断输出结果是否包含字符串，没有则立即返回。有则等待timeout时间后再返回。【交互式输入】
# send命令，执行交互动作。
# exp_continue命令，继续执行交互动作。
# interact命令，执行完交互动作后，把控制权交给控制台，若无该命令，交互完直接退出。
# $argv：expect脚本可以接受bash传递过来的参数，可以使用[lindex $argv n]获得，n从0开始。
# 交互式输入账号密码使用ssh登录远程主机
# 默认timeout为10s
[root@client ~]# vim ssh.exp
#!/usr/bin/expect
set ipaddr "192.168.10.10"
set name "root"
set passwd "123456"
set timeout 30
spawn ssh $name@$ipaddr
expect {
"yes/no" {
send "yes\r";exp_continue}
"password" {
send "$passwd\r"}
}
expect {
"#"}
send "touch /root/a.txt\r"
send "ls /etc > /root/a.txt\r"
send "exit\r"
expect eof
[root@client ~]# chmod +x ssh.exp
[root@client ~]# expect ssh.exp
spawn ssh [email protected]
[email protected]'s password:
Last login: Sun Aug 2 20:32:30 2020 from 192.168.10.43
[root@master-lvs ~]# touch /root/a.txt
[root@master-lvs ~]# ls /etc > /root/a.txt
[root@master-lvs ~]# exit
登出
Connection to 192.168.10.10 closed.
# 免密使用ssh登录多台远程主机进行操作
[root@client ~]# vim ipaddr.txt
192.168.10.10 123456
192.168.10.20 123456
[root@client ~]# vim ssh.exp
#!/usr/bin/expect
set ipaddr [lindex $argv 0]
set name "root"
set passwd [lindex $argv 1]
set timeout 30
spawn ssh $name@$ipaddr
expect {
"yes/no" {
send "yes\r";exp_continue}
"password" {
send "$passwd\r"}
}
expect {
"#"}
send "touch /root/a.txt\r"
send "ls /etc > /root/a.txt\r"
send "exit\r"
expect eof
[root@client ~]# chmod +x ssh.exp
[root@client ~]# vim login.sh
#!/bin/bash
for ip in `awk '{print $1}' /root/ipaddr.txt`
do
pass=`grep $ip /root/ipaddr.txt | awk '{print $2}'`
expect /root/ssh.exp $ip $pass
done
[root@client ~]# chmod +x login.sh
# 执行登录脚本
[root@client ~]# bash login.sh
spawn ssh [email protected]
[email protected]'s password:
Last login: Sun Aug 2 21:08:42 2020 from 192.168.10.43
[root@master-lvs ~]# touch /root/a.txt
[root@master-lvs ~]# ls /etc > /root/a.txt
[root@master-lvs ~]# exit
登出
Connection to 192.168.10.10 closed.
spawn ssh [email protected]
[email protected]'s password:
Last login: Sun Aug 2 21:09:23 2020 from 192.168.10.43
[root@backup_lvs ~]# touch /root/a.txt
[root@backup_lvs ~]# ls /etc > /root/a.txt
[root@backup_lvs ~]# exit
登出
Connection to 192.168.10.20 closed.
2. shell正则表达式
基础正则表达式
| 特殊字符 | 描述 |
|---|---|
| ^ | 匹配开头 |
| $ | 匹配结尾 |
| * | 匹配前一个字符0次或多次，匹配*用\* |
| + | 匹配前一个字符1次或多次，匹配*用\+ |
| ? | 匹配前一个字符0次或1次，匹配*用\? |
| \ | 转义符 |
| . | 匹配除了换行符\n外的所有单个字符 |
| () | 匹配圆括号表达式的开始位置和结束位置，匹配(用\(，匹配)用\) |
| [] | 匹配方括号表达式的开始位置和结束位置，匹配[用\[，匹配]用\] |
| {} | 匹配大括号表达式的开始位置和结束位置，匹配{用\{，匹配}用\} |
| | | 或 ，匹配|用\ |
| \n | 匹配换行符 |
| \r | 匹配回车符 |
| \t | 匹配制表符 |
# 去除/etc/ssh/sshd_config文件中的空行和#号开头的行
# 使用基础正则表达式
[root@client ~]# cat /etc/ssh/ssh_config | grep -v "^$" | grep -v "^#"
[root@client ~]# cat /etc/ssh/ssh_config | grep -v "^$\|^#"
# 使用扩展正则表达式
[root@client ~]# cat /etc/ssh/ssh_config | grep -E -v "^$|^#"
[root@client ~]# cat /etc/ssh/ssh_config | egrep -v "^$|^#"
# 匹配.字符,除换行符\n外的所有单个字符
[root@client ~]# grep .ot /etc/passwd
root:x:0:0:root:/root:/bin/bash
operator:x:11:0:operator:/root:/sbin/nologin
setroubleshoot:x:991:985::/var/lib/setroubleshoot:/sbin/nologin
3. bash检查脚本和查看脚本执行过程
3.1 bash检查脚本是否存在语法错误
bash -v script_name.sh 查看bash是否存在语法错误
[root@client ~]# cat ping.sh
#!/bin/bash
for ((i=40;i<45;i++))
do
ping -c 3 192.168.10.$i &> /dev/null
if [ $? -ne 0 ] ; then
echo "192.168.10.$i is shutdown"
else
echo "192.168.10.$i is startup"
fi
done
[root@client ~]# bash -v ping.sh
#!/bin/bash
for ((i=40;i<45;i++))
do
ping -c 3 192.168.10.$i &> /dev/null
if [ $? -ne 0 ] ; then
echo "192.168.10.$i is shutdown"
else
echo "192.168.10.$i is startup"
fi
done
192.168.10.40 is shutdown
192.168.10.41 is shutdown
192.168.10.42 is shutdown
192.168.10.43 is startup
192.168.10.44 is shutdown
3.2 bash查看脚本详细执行过程
bash -x script_name.sh 查看bash详细的执行过程
[root@client ~]# cat ping.sh
#!/bin/bash
for ((i=40;i<45;i++))
do
ping -c 3 192.168.10.$i &> /dev/null
if [ $? -ne 0 ] ; then
echo "192.168.10.$i is shutdown"
else
echo "192.168.10.$i is startup"
fi
done
[root@client ~]# bash -x ping.sh
+ (( i=40 ))
+ (( i<45 ))
+ ping -c 3 192.168.10.40
+ '[' 1 -ne 0 ']'
+ echo '192.168.10.40 is shutdown'
192.168.10.40 is shutdown
+ (( i++ ))
+ (( i<45 ))
+ ping -c 3 192.168.10.41
+ '[' 1 -ne 0 ']'
+ echo '192.168.10.41 is shutdown'
192.168.10.41 is shutdown
+ (( i++ ))
+ (( i<45 ))
+ ping -c 3 192.168.10.42
+ '[' 1 -ne 0 ']'
+ echo '192.168.10.42 is shutdown'
192.168.10.42 is shutdown
+ (( i++ ))
+ (( i<45 ))
+ ping -c 3 192.168.10.43
+ '[' 0 -ne 0 ']'
+ echo '192.168.10.43 is startup'
192.168.10.43 is startup
+ (( i++ ))
+ (( i<45 ))
+ ping -c 3 192.168.10.44
+ '[' 1 -ne 0 ']'
+ echo '192.168.10.44 is shutdown'
192.168.10.44 is shutdown
+ (( i++ ))
+ (( i<45 ))