1 信号捕捉 trap
trap 命令可以捕捉信号，修改信号原来的功能，实现自定义功能
常用参数：
| -l | 让shell打印一个命令名称和其相对应的编号的列表 |
|---|---|
| -p | 打印与每一个信号有关联的命令的列表 |
| 缺省 | 每个接收到的sigspec信号都将会被重置为它们进入shell时的值 |
| -f | 阻止中断信号 |
#查看信号列表trap -l2) SIGINT ：是Ctrl+C的按键信号### 信号的值可以写成三种格式：## 2(数字法表示) | SIGINT(全称) | INT(简称)#进程收到系统发出的指定信号后，将执行自定义指令，而不会执行原操作trap '触发指令' 信号#忽略信号的操作trap '' 信号#恢复原信号的操作trap '-' 信号#列出自定义信号操作trap -p#当前脚本退出时，执行finish函数（重要）trap finish EXIT
范例：
#!/bin/bash#自定义指令信号trap "echo 'Please Ctrl+C or Ctlr+\'" SIGINT SIGQUITtrap -pfor ((i=0;i<=10;i++))dosleep 1echo $idone#忽略原信号操作trap '' SIGINTtrap -pfor ((i=11;i<=20;i++))dosleep 1echo $idone#恢复原信号操作trap '-' SIGINTtrap -pfor ((i=21;i<=30;i++))dosleep 1echo $idone
范例：当脚本正常或者异常退出时，也会执行 finish 函数
~ vim trap-exit.sh#!/bin/bashfunction finish(){echo finish is at `date +%F_%T` | tee -a /root/finish.log}#捕获退出就执行finish函数trap finish exitwhile true ;doecho runningsleep 1done
2 创建临时文件 mktemp
mktemp 命令用于创建并显示临时文件，可以避免冲突
格式：
mktemp [OPTIONS]... [TEMPLATE]说明：TEMPLATE: filenameXXX，X至少要出现三个，三个以上随机字符
常用选项：
-d #创建临时目录-p DIR或者--tmpdir=DIR #指明临时文件所存放目录位置
范例：
~ mktemp/tmp/tmp.lOLpKJ8nrB~ mktemp /tmp/testXXX~ tmpdir=`mktemp -d /tmp/testdirXXX`~ mktemp --tmpdir=tmpdir testXXXXXX~ mktemp -d tmpdirXXX -p /usr/local/src
范例：实现文件垃圾箱功能
#方法1：脚本实现~ vim /data/shell/mktemp-rm.sh#!/bin/bashDIR=$(mktemp -d /tmp/trash-$(date +%F_%T)XXX)mv $* $DIRecho $* is move to $DIR~ chmod +x /data/shell/mktemp-rm.sh~ alias rm=/data/shell/mktemp-rm.sh~ rm finish.logfinish.log is move to /tmp/trash-2022-06-14_17:35:45jX0#方法2：函数实现~ function rm() { local trash=$(mktemp -d /tmp/trash-$(date +%F_%T)XXX);mv $* $trash; }
3 安装复制文件 install
install 功能相当于 cp，chmod，chown，chgrp，mkdir等相关工具的集合
install 命令格式：
Usage: install [OPTION]... [-T] SOURCE DESTor: install [OPTION]... SOURCE... DIRECTORYor: install [OPTION]... -t DIRECTORY SOURCE...or: install [OPTION]... -d DIRECTORY...
选项：
-m MODE 权限，默认755-o OWNER 用户-g GROUP 用户组-d DIRNAME 目录
范例：
~ install -m 700 -o wang -g admins srcfile dstfile
#-d:相当于mkdir -p
~ install -m 700 -d /testdir/installdir
~ install -m 600 -o wang -g bin reset.sh /data/set.sh
~ ls -l /data/set.sh
~ install -m 700 -o kubesphere -g daemon -d /data/testdir
~ ls -ld /data/testdir
4 交互式转换批处理工具 expect
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 处理交互的命令，可以将交互过程如：ssh登录，ftp登录等写在一个脚本上，使之自动化完成。尤其适用于需要对多台服务懦执行相同操作的环境中，可以大大提高系统管理人员的工作效率。
范例：安装expect 及mkpasswd工具
➜ ~ yum install -y expect
➜ ~ rpm -ql expect | head
/usr/bin/autoexpect
/usr/bin/dislocate
/usr/bin/expect
/usr/bin/ftp-rfc
/usr/bin/kibitz
/usr/bin/lpunlock
/usr/bin/mkpasswd
/usr/bin/passmass
/usr/bin/rftp
/usr/bin/rlogin-cwd
➜ ~ mkpasswd
gBOlu87i<
➜ ~ mkpasswd -l 15 -d 3 -C 5
@k5FpJ9XRsPaj1i
expect 语法：
expect [选项] [ -c cmds ] [[ -[flb] ] cmdfile ] [ args ]
常见选项：
-c：从命令行执行expect脚本,默认expect是交互地执行的
-d：可以调试信息
示例：
expect -c 'expect "\n" { send "pressed enter\n" }'
expect -d ssh.exp
expect 中的相关命令
- spawn 启动新的进程
- expect 从进程接收字符串
- send 用于向进程发送字符串
- interact 允许用户交互（将权限交给用户）
- exp_continue 匹配多个字符串在执行动作后如此命令（在 expect 中多次匹配就需要用到）
- eof export 执行结束退出
- send_user 用来打印输出，相当于 shell 中的 echo
- exit 退出expect脚本
- set 定义变量
- puts 输出变量
- set timeout 设置超时时间
expect 最常用的语法：(TCL语言：模式-动作)
单一分支模式语法：
#直接执行expect则是交互式
~ expect
#一次性的。
expect1.1> expect "hi" {send "You said hi\n"}
hi
You said hi
expect1.2> expect "hi" {send "You said hi\n"}
123hihello
You said hi
匹配到 hi 后，会输出”You said hi”，并换行
多分支模式语法：
~ expect
expect1.1> expect "hi" { send "You said hi\n" } "hehe" { send "Hehe yourself\n" } "bye" { send "Good bye\n" }
hehe
Hehe yourself
expect1.2> expect "hi" { send "You said hi\n" } "hehe" { send "Hehe yourself\n" } "bye" { send "Good bye\n" }
bye
Good bye
expect1.3> expect "hi" { send "You said hi\n" } "hehe" { send "Hehe yourself\n" } "bye" { send "Good bye\n" }
hi
You said hi
匹配 hi，hello，bye 任意字符串时，执行相应输出。等同如下：
expect {
"hi" { send "You said hi\n" }
"hehe" { send "Hehe yourself\n" }
"bye" { send "Good bye\n" }
}
~ expect1.1> expect {
+> "hi" { send "You said hi\n" }
+> "hehe" { send "Hehe yourself\n" }
+> "bye" { send "Good bye\n" }
+> }
bye
Good bye
expect1.2>
范例1：非交互式复制文件
~ vim expect-scp
#!/usr/bin/expect
spawn scp /etc/redhat-release 10.0.0.170:/data
expect {
"yes/no" { send "yes\n";exp_continue }
"password" { send "magedu\n" }
}
expect eof
范例2：自动登录
~ vim expect-ssh
#!/usr/bin/expect
spawn ssh 10.0.0.170
expect {
"yes/no" { send "yes\n";exp_continue }
"password" { send "magedu\n" }
}
interact
范例3：expect 变量
~ vim expect-set-ssh
#!/usr/bin/expect
set ip 10.0.0.170
set user root
set password magedu
set timeout 10
spawn ssh $user@$ip
expect {
"yes/no" { send "yes\n";exp_continue }
"password" { send "$password\n" }
}
interact
范例4：expect 位置参数
~ vim expect-arg
#!/usr/bin/expect
set ip [lindex $argv 0]
set user [lindex $argv 1]
set password [lindex $argv 2]
spawn ssh $user@$ip
expect {
"yes/no" { send "yes\n";exp_continue }
"password" { send "$password\n" }
}
interact
~ chmod +x expect-args
~ ./expect-args 10.0.0.170 root magedu
spawn ssh root@10.0.0.170
root@10.0.0.170's password:
Last login: Tue Jun 14 21:42:04 2022 from 10.0.0.160
[root@kubesphere-mysql57 ~]#logout
Connection to 10.0.0.170 closed.
范例5：expect 执行多条命令
~ vim expect-command
#!/usr/bin/expect
set ip [lindex $argv 0]
set user [lindex $argv 1]
set password [lindex $argv 2]
spawn ssh $user@$ip
expect {
"yes/no" { send "yes\n";exp_continue }
"password" { send "$password\n" }
}
expect "]#" { send "useradd haha\n" }
expect "]#" { send "echo Admin@h3c | passwd --stdin haha\n"}
send "exit\n"
expect eof
~ ./expect-command 10.0.0.170 root magedu
范例6：shell 脚本调用 expect
~ vim shell-expect.sh
#!/bin/bash
#Shell ENV
ip=${1}
user=${2}
password=${3}
expect <<EOF
set timeout 20
spawn ssh $user@$ip
expect {
"yes/no" { send "yes\n";exp_continue }
"password" { send "$password\n" }
}
expect "]#" { send "useradd hehe\n"}
expect "]#" { send "echo Admin@h3c | passwd --stdin hehe\n" }
expect "]#" { send "exit\n" }
expect eof
EOF
~ chmod +x bash-expect.sh
~ ./bash-expect.sh 10.0.0.170 root magedu
范例7：shell脚本利用循环调用 expect 在 CentOS 和Ubuntu上批量创建用户
~ vim export-ubuntu-centos-useradd.sh
#!/bin/bash
#SHELL ENV
net=10.0.0
user=root
password=magedu
IPLIST="
51
52
53
"
for ID in $IPLIST ;do
ip=$net.$ID
expect <<EOF
set timeout 20
spawn ssh $user@$ip
expect {
"yes/no" { send "yes\n";exp_continue }
"password" { send "$password\m" }
}
expect "#" { send "useradd test\n" }
expect "#" { send "exit\n" }
expect eof
EOF
done
范例：修改配置文件 SELinux
~ vim expect-selinux.sh
#!/bin/bash
#SHELL ENV
net=10.0.0
user=root
password=magedu
IPLIST="
51
52
53
"
for ID in $IPLIST ;do
ip=$net.$ID
expect <<EOF
set timeout 20
spawn ssh $user@$ip
expect {
"yes/no" { send "yes\n";exp_continue }
"password" { send "$password\m" }
}
expect "#" { send "sed -i 's/^SELINUX=enforcing/SELINUX=disabled/g' /etc/selinux/config\n" }
expect "#" { send "setenforce 0\n" }
expect "#" { send "exit\n" }
expect eof
EOF
done
范例：在指定主机执行批量操作
~ vim expect-scp.sh
#!/bin/bash
net=10.0.0
user=root
password=magedu
for i in {51..53} ;do
ip=$net.$i
expect <<EOF
set timeout 20
spawn scp /etc/selinux/config $user@$ip:/data
expect {
"yes/no" { send "yes\n";exp_continue }
"password" { send "$password\n" }
}
spawn ssh $user@$ip
expect {
"yes/no" { send "yes\n";exp_continue }
"password" { send "$password\n" }
}
expect "root" { send "useradd kubesphere\n" }
expect "root" { send "echo Admin@h3c | passwd --stdin kubesphere\n" }
expect "root" { send "exit\n" }
expect eof
EOF
done
~ chmod +x expect-scp.sh
~ ./expect-scp.sh
若有收获，就点个赞吧
0 人点赞
