1. 多行重定向
cat <<EOF #打印在屏幕上
cat <<a.txt #不打印在屏幕上
[root@localhost ~]#cat <<EOF
> HELLO
> HI
> OK
> EOF
HELLO
HI
OK
[root@localhost ~]#cat <<EOF >test #传给test
HELLO
HI
OK
EOF
[root@localhost ~]#cat test #查看test
HELLO
HI
OK
2. Expect
-
定义：是建立在tcl（tool command language）语言基础上的一个工具，常被用于进行自动化控制和测试，解决shell脚本中交互的相关问题
-
Expect概述（与ssh相互配合使用）
- 建立在tcl之上的工具
- 用于进行自动化控制和测试
- 解决shell脚本中交互相关的问题
-
基本命令
- 判断上次输出结果中是否包含指定的字符串，如果有则立即返回，否则就等待超时时间后返回
- 只能捕捉由spawn启动的进程的输出
- 用于接收命令执行后的输出，然后和期望的字符串匹配
-
send
- 向进程发送字符串，用于模拟用户的输入
- 该命令不能自动回车换行，一般要加\r（回车）
-
set
- 设置超时时间，过期则继续执行后续指令
- 单位是秒
- timeout -1表示永不超时
- 默认情况下，timeout是10秒
-
exp_continue
- 允许expect继续向下执行指令
-
send_user
- 回显命令，相当于echo
基本命令：
#脚本解释器
#！/usr/bin/expect（不用.sh结尾）
#spawn 后面通常跟一个Linux执行命令，表示开启一个会话、进程，并跟踪后续交互信息
例：spawn ssh 192.168.8.8
#expect
判断上次输出结果中是否包含指定的字符串，如果有则立即返回，否则就等待超时时间后返回；只能捕捉有swpan启动的进程输出
用于接受命令执行后的输出，然后和期望的字符串匹配
#send
向进程发送字符串，用于模拟用户的输入：该命令不能自动回车换行，一般要加 \r (回车) 或者\n
```bash
#！/usr/bin/expect
#设置超时时间
set timeout 5
#参数传入
set hostname [lindex $argv 0]
#hostname=$1
set password [lindex $argv 1]
#password=$2
[root@localhost ~]#rpm -q expect #先查看是否安装expect，没有安装需要先安装（yum install expect -y）
expect-5.45-14.el7_1.x86_64
[root@localhost ~]#rpm -q tcl
tcl-8.5.13-8.el7.x86_64
[root@localhost ~]#vim test
#!/usr/bin/expect
spawn ssh 192.168.8.106 #启动命令
expect { #捕捉spawn启动的进程的输出
"yes/no" { send "yes\r"; exp_continue } #捕捉yes或no，exp continue代表继续捕捉
"password" { send "123123\r" } #继续捕捉
}
#expect eof #代表结束，结束返回之前终端
interact #代表结束，留在远程终端
[root@localhost ~]#chmod +x test
[root@localhost ~]#./test #执行脚本
spawn ssh 192.168.8.106
The authenticity of host '192.168.8.106 (192.168.8.106)' can't be established.
ECDSA key fingerprint is SHA256:e+J0VzcMDN/wqEMfgMwrXc+Gef7K/KjlHOIBeDyWFeI.
ECDSA key fingerprint is MD5:df:f7:b3:3f:f6:0e:64:6a:95:db:a7:09:a0:18:89:ee.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.8.106' (ECDSA) to the list of known hosts.
root@192.168.8.106's password:
Last login: Tue Aug 15 09:12:01 2023 from 192.168.8.1
[root@localhost ~]#
[root@localhost ~]#exit
登出
Connection to 192.168.8.106 closed.
[root@localhost ~]#
[root@localhost ~]#vim /data/test
#!/usr/bin/expect
set hostname [ lindex $argv 0 ]
spawn ssh $hostname
expect {
"yes/no" { send "yes\r";exp_continue }
"password" { send "123123\r" }
}
#expect eof
interact
[root@localhost ~]#chmod +x /data/test
[root@localhost ~]#/data/test 192.168.8.106
spawn ssh 192.168.8.106
The authenticity of host '192.168.8.106 (192.168.8.106)' can't be established.
ECDSA key fingerprint is SHA256:e+J0VzcMDN/wqEMfgMwrXc+Gef7K/KjlHOIBeDyWFeI.
ECDSA key fingerprint is MD5:df:f7:b3:3f:f6:0e:64:6a:95:db:a7:09:a0:18:89:ee.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.8.106' (ECDSA) to the list of known hosts.
root@192.168.8.106's password:
Last login: Thu Aug 17 17:50:25 2023
[root@localhost ~]#exit
登出
Connection to 192.168.8.106 closed.
[root@localhost ~]#vim test.sh
#!/bin/bash
hostname=$1
password=$2
/usr/bin/expect <<EOF
spawn ssh root@$hostname
expect {
"(yes/no)"
{send "yes\r";exp_continue}
"*password"
{send "$password\r"}
}
expect "*]#" #只要出现以]#结尾的就新建用户zhangsan
send "useradd zhangsan\r"
expect eof
EOF
[root@localhost ~]#bash test.sh 192.168.8.106 123123
spawn ssh root@192.168.8.106
root@192.168.8.106's password:
Last login: Thu Aug 17 18:51:50 2023 from 192.168.8.100
[root@localhost ~]#useradd zhangsan
[root@localhost ~]#
[root@localhost ~]#id zhangsan
uid=1001(zhangsan) gid=1001(zhangsan) 组=1001(zhangsan)
#!/bin/bash
password="123123"
hostlist="
192.168.8.106
192.168.8.101
"
for i in $hostlist
do
/usr/bin/expect <<EOF
spawn ssh root@$i
expect {
"(yes/no)"
{send "yes\r";exp_continue}
"*password"
{send "$password\r"}
}
expect "*]#"
send "useradd zhangsan\r"
expect eof
EOF
done
3. awk数组
[root@localhost ~]#awk 'BEGIN{student[1]="TZONG";student[2]="YZONG";student[3]="IZONG";for(i in student){print i"---->"student[i]}}'
1---->TZONG
2---->YZONG
3---->IZONG
[root@localhost ~]#awk 'BEGIN{student["a"]="TZONG";student["b"]="YZONG";student["c"]="IZONG";for(i in student){print i"---->"student[i]}}'
a---->TZONG
b---->YZONG
c---->IZONG
[root@localhost ~]#awk 'BEGIN{student["aa"]="TZONG";student["b"]="YZONG";student["c"]="IZONG";for(i in student){print i"---->"student[i]}}' #顺序可以变化
b---->YZONG
c---->IZONG
aa---->TZONG
4. 去除重复行实例
[root@localhost ~]#vim test
[root@localhost ~]#cat test
abc
def
ghi
abc
ghi
def
afa
ghi
[root@localhost ~]#awk '!a[$0]++' test #输出不重复的行
abc
def
ghi
afa
