case "變量" in
 值1)
 指令1...
 ;;
 值2)
 指令2...
 ;;
 *）
 指令3...
esac

case "找工作條件" in
 給的錢(qián)多)
 給你工作...
 ;;
 給股份)
 給你工作...
 ;;
 有發(fā)展前景)
 可以試試...
 ;;
 *)
 bye bye !!
esac

[root@shell scripts]# cat num.sh 
#!/bin/bash

#create by guoke
#function number input

read -p "please input a number：" num #打印信息提示用戶(hù)輸入，輸入信息賦值給num變量

case "$num" in
 1)
 echo "The num you input is 1"
 ;;
 [2-5])
 　　echo "The num you input is 2-5"
 ;;
 [6-9])
 　　echo "The num you input is 6-9"
 ;;
 *)
 　　echo "please input number[1-9] int"
 　　 exit;
esac

[root@shell scripts]# cat menu.sh 
#!/bin/bash

#create by guoke
#function print menu

RED_COLOR='\E[1;31m'
GREEN_COLOR='\E[1;32m'
YELLOW_COLOR='\E[1;33m'
BLUE_COLOR='\E[1;34m'
RES='\E[0m'

echo ' #使用echo打印菜單
#############################
 1.banana
 2.apple
 3.pear
 4.cherry
#############################
'

read -p "please select a num：" num

case "$num" in
 1)
 　　echo -e "${YELLOW_COLOR} banana ${RES}"
 ;;
 2)
 　　echo -e "${RED_COLOR} apple ${RES}"
 ;;
 3)
 　　echo -e "${GREEN_COLOR} pear ${RES}"
 ;;
 4)
 　　echo -e "${BLUE_COLOR} cherry ${RES}"
 ;;
 *)
 　　echo "please input {1|2|3|4}"
esac

cat<<-EOF
===============================
 1.banana
 2.apple
 3.pear
 4.cherry
===============================
EOF

[root@shell scripts]# sh menu.sh 

#############################
1.banana
2.apple
3.pear
4.cherry
#############################

please select a num：
please input {1|2|3|4} 

#!/bin/bash
yum install gcc pcre pcre-devel wget openssl openssl-devel.x86_64 -y 
mkdir -p /home/demo/tools
cd /home/demo/tools/
wget -q http://nginx.org/download/nginx-1.6.3.tar.gz
useradd nginx -s /sbin/nologin -M
tar xf nginx-1.6.3.tar.gz 
cd nginx-1.6.3/
./configure --user=nginx --group=nginx --prefix=/application/nginx --with-http_stub_status_module --with-http_ssl_module
make
make install
ln -s /application/nginx-1.6.3 /application/nginx/ #做軟連接
/application/nginx/sbin/nginx -t #檢查語(yǔ)法
/application/nginx/sbin/nginx #啟動(dòng)服務(wù)

[root@shell init.d]# chmod +x /etc/init.d/nginxd
[root@shell init.d]# cat nginxd 
#!/bin/bash
#chkconfig: 2345 40 98 #設(shè)定2345級(jí)別，開(kāi)機(jī)第40位啟動(dòng)腳本，關(guān)機(jī)第98位關(guān)閉腳本

#create by guoke
#email:1075792988@qq.com
#function nginx start scripts

[ -f /etc/init.d/functions ] && source /etc/init.d/functions #引入系統(tǒng)函數(shù)庫(kù)

PIDFILE=/application/nginx/logs/nginx.pid #定義PID文件路徑
NGINX=/application/nginx/sbin/nginx #定義啟動(dòng)命令路徑

value(){ #定義返回值函數(shù)
 RETVAL=$?
 if [ $RETVAL -eq 0 ];then
 　　action "Nginx is $1" /bin/true
 else
 　　action "Nginx is $1" /bin/true
 fi
}

start(){ #定義啟動(dòng)函數(shù)
 if [ -f $PIDFILE ];then #判斷PIDFILE存不存在，存在就打印運(yùn)行，否則就啟動(dòng)
 　　echo "Nginx is running"
 else
 　　$NGINX
 　　value start #調(diào)用返回值函數(shù)
 fi
}

stop(){ #定義停止函數(shù)
 if [ ! -f $PIDFILE ];then #也是通過(guò)判斷PID文件是否存在然后進(jìn)行相關(guān)操作
 　　echo "Nginx not running"
 else
 　　$NGINX -s stop
 　　value stop
 fi
}

reload(){ #定義重啟函數(shù)
 if [ ! -f $PIDFILE ];then
 　　echo "not open $PIDFILE no such directory"
 else
 　　$nginx -s reload
 　　value reload
 fi
}

case "$1" in #使用case接收腳本傳參的字符串
 start) #如果第一個(gè)參數(shù)為start，調(diào)用start函數(shù)
 　　start
 ;;
 stop) #如果第一個(gè)參數(shù)為stop，調(diào)用stop函數(shù)
 　　stop
 ;;
 reload)
 　　stop
 　　sleep 1
 　　start
 ;;
 *)
 　　echo "USAGE:$0 {stop|start|reload}"
 　　exit 1
esac

[demo@shell ~]$ ssh-keygen -t dsa -P "" -f ~/.ssh/id_dsa 
Generating public/private dsa key pair.
Enter file in which to save the key (/home/demo/.ssh/id_dsa): 
Created directory '/home/demo/.ssh'.
Your identification has been saved in /home/demo/.ssh/id_dsa.
Your public key has been saved in /home/demo/.ssh/id_dsa.pub.
The key fingerprint is:
SHA256:BTFfcC2hMKBzuZeUYylC3qgza7z4X6j3RBlwq8Beoak demo@shell
The key's randomart image is:
+---[DSA 1024]----+
| + o.*...+o |
| . = B o O +. . |
| = B B * + . |
| o + = B + |
|E = . + S |
| . + o .  |
| + . o  |
| o o.o  |
|..+o...  |
+----[SHA256]-----+
#命令說(shuō)明：一鍵生成密鑰，不用按回車(chē)。-t：指定要?jiǎng)?chuàng)建的密鑰類(lèi)型，-P：提供舊密碼，空表示不需要密碼，-f：指定位置

#將公鑰拷貝到其他服務(wù)器的demo用戶(hù)
[demo@shell ~]$ ssh-copy-id -i .ssh/id_dsa.pub "demo@192.168.86.129"
[demo@shell ~]$ ssh-copy-id -i .ssh/id_dsa.pub "demo@192.168.86.130"
[demo@shell ~]$ ssh-copy-id -i .ssh/id_dsa.pub demo@192.168.86.131

[root@shell scripts]# cat tiaobanji.sh 
#!/bin/bash

trapper(){ #定義屏蔽信號(hào)函數(shù)
 trap '' INT QUIT TSTP TERM HUB
}

menu(){ #定義菜單列表函數(shù)
 cat<<-EOF #加-后面的EOF就可以不用頂格
==============Host List==============
 1) 192.168.86.129
 2) 192.168.86.130
 3) 192.168.86.131
 4) 192.168.86.132
 5) exit
=====================================
 EOF
}

USER=demo

host(){ #定義主機(jī)列表函數(shù)
 case "$1" in
 1)
 ssh $USER@192.168.86.129
 ;;
 2)
 ssh $USER@192.168.86.130
 ;;
 3)
 ssh $USER@192.168.86.131
 ;;
 4)
 ssh $USER@192.168.86.132
 ;;
 5)
 exit
esac
}

main(){ #定義主函數(shù)
 while : #while循環(huán)，一直循環(huán)
 do
 trapper #調(diào)用trapper函數(shù)
 clear #清屏
 menu #調(diào)用菜單函數(shù)
 read -p "please select a num：" num #獲取用戶(hù)輸入
 host $num #調(diào)用主機(jī)列表函數(shù)和傳入的參數(shù)，進(jìn)行遠(yuǎn)程登錄
 done
}
main #調(diào)用主函數(shù)

[root@shell ~]# cd /etc/profile.d/
[root@shell profile.d]# cat jump.sh 
#!/bin/bash

[ $UID -ne 0 ] && . /scripts/tiaobanji.sh

==============Host List==============
1) 192.168.86.129
2) 192.168.86.130
3) 192.168.86.131
4) 192.168.86.132
5) exit
=====================================
please select a num：1 #進(jìn)行選擇
Last login: Tue Mar 31 23:48:33 2020 from 192.168.86.128
[demo@mysql ~]$