As a Linux engineer, being able to write good scripts can not only improve work efficiency, but also give you more time to do your own things. When I was surfing the Internet recently, I also paid attention to collecting some scripts written by big guys, and summarized them. Welcome to collect them, and share with you!
(1) The user guesses the number
#!/bin/bash
# 脚本生成一个 100 以内的随机数,提示用户猜数字,根据用户的输入,提示用户猜对了,
# 猜小了或猜大了,直至用户猜对脚本结束。
# RANDOM 为系统自带的系统变量,值为 0‐32767的随机数
# 使用取余算法将随机数变为 1‐100 的随机数
num=$[RANDOM%100+1]
echo "$num"
# 使用 read 提示用户猜数字
# 使用 if 判断用户猜数字的大小关系:‐eq(等于),‐ne(不等于),‐gt(大于),‐ge(大于等于),
# ‐lt(小于),‐le(小于等于)
while :
do
read -p "计算机生成了一个 1‐100 的随机数,你猜: " cai
if [ $cai -eq $num ]
then
echo "恭喜,猜对了"
exit
elif [ $cai -gt $num ]
then
echo "Oops,猜大了"
else
echo "Oops,猜小了"
fi
done
(2) Check how many remote IPs are connecting to this machine
#!/bin/bash
#!/bin/bash
# 查看有多少远程的 IP 在连接本机(不管是通过 ssh 还是 web 还是 ftp 都统计)
# 使用 netstat ‐atn 可以查看本机所有连接的状态,‐a 查看所有,
# -t仅显示 tcp 连接的信息,‐n 数字格式显示
# Local Address(第四列是本机的 IP 和端口信息)
# Foreign Address(第五列是远程主机的 IP 和端口信息)
# 使用 awk 命令仅显示第 5 列数据,再显示第 1 列 IP 地址的信息
# sort 可以按数字大小排序,最后使用 uniq 将多余重复的删除,并统计重复的次数
netstat -atn | awk '{print $5}' | awk '{print $1}' | sort -nr | uniq -c
(3）helloworld
#!/bin/bash
function example {
echo "Hello world!"
}
example
(4) Print the pid of tomcat
#!/bin/sh`
v1="Hello"
v2="world"
v3=${v1}${v2}
echo $v3
pidlist=`ps -ef|grep apache-tomcat-7.0.75|grep -v "grep"|awk '{print $2}'`
echo $pidlist
echo "tomcat Id list :$pidlist" //显示pid
(5) Scripting a rock-paper-scissors game
#!/bin/bash
game=(石头 剪刀 布)
num=$[RANDOM%3]
computer=${game[$sum]}
echo "请根据下列提示选择您的出拳手势"
echo " 1. 石头"
echo " 2. 剪刀"
echo " 3. 布 "
read -p "请选择 1-3 ：" person
case $person in
1)
if [ $num -eq 0 ]
then
echo "平局"
elif [ $num -eq 1 ]
then
echo "你赢"
else
echo "计算机赢"
fi;;
2)
if [ $num -eq 0 ]
then
echo "计算机赢"
elif [ $num -eq 1 ]
then
echo "平局"
else
echo "你赢"
fi;;
3)
if [ $num -eq 0 ]
then
echo "你赢"
elif [ $num -eq 1 ]
then
echo "计算机赢"
else
echo "平局"
fi;;
*)
echo "必须输入1-3 的数字"
esac
(6) Ninety-nine multiplication table
#!/bin/bash
for i in `seq 9`
do
for j in `seq $i`
do
echo -n "$j*$i=$[i*j] "
done
echo
done
(7) The script uses source code to install the memcached server
#!/bin/bash
# 一键部署 memcached
# 脚本用源码来安装 memcached 服务器
# 注意:如果软件的下载链接过期了,请更新 memcached 的下载链接
wget http://www.memcached.org/files/memcached-1.5.1.tar.gz
yum -y install gcc
tar -xf memcached‐1.5.1.tar.gz
cd memcached‐1.5.1
./configure
make
make install
(8) Detect whether the current user of this machine is a super administrator
#!/bin/bash
# 检测本机当前用户是否为超级管理员,如果是管理员,则使用 yum 安装 vsftpd,如果不
# 是,则提示您非管理员(使用字串对比版本)
if [ $USER == "root" ]
then
yum -y install vsftpd
else
echo "您不是管理员，没有权限安装软件"
fi
(9) if operation expression
#!/bin/bash -xv
if [ $1 -eq 2 ] ;then
echo "wo ai wenmin"
elif [ $1 -eq 3 ] ;then
echo "wo ai wenxing "
elif [ $1 -eq 4 ] ;then
echo "wo de xin "
elif [ $1 -eq 5 ] ;then
echo "wo de ai "
fi
(10) The script kills the tomcat process and restarts
#!/bin/bash
#kill tomcat pid
pidlist=`ps -ef|grep apache-tomcat-7.0.75|grep -v "grep"|awk '{print $2}'` #找到tomcat的PID号
echo "tomcat Id list :$pidlist" //显示pid
kill -9 $pidlist #杀掉改进程
echo "KILL $pidlist:" //提示进程以及被杀掉
echo "service stop success"
echo "start tomcat"
cd /opt/apache-tomcat-7.0.75
pwd
rm -rf work/*
cd bin
./startup.sh #;tail -f ../logs/catalina.out
(11) Print the chess board
#!/bin/bash
# 打印国际象棋棋盘
# 设置两个变量,i 和 j,一个代表行,一个代表列,国际象棋为 8*8 棋盘
# i=1 是代表准备打印第一行棋盘,第 1 行棋盘有灰色和蓝色间隔输出,总共为 8 列
# i=1,j=1 代表第 1 行的第 1 列;i=2,j=3 代表第 2 行的第 3 列
# 棋盘的规律是 i+j 如果是偶数,就打印蓝色色块,如果是奇数就打印灰色色块
# 使用 echo ‐ne 打印色块,并且打印完成色块后不自动换行,在同一行继续输出其他色块
for i in {1..8}
do
for j in {1..8}
do
sum=$[i+j]
if [ $[sum%2] -eq 0 ];then
echo -ne "\033[46m \033[0m"
else
echo -ne "\033[47m \033[0m"
fi
done
echo
done
(12) Count the number of accounts that can log in to the computer in the current Linux system
#!/bin/bash
# 统计当前 Linux 系统中可以登录计算机的账户有多少个
#方法 1:
grep "bash$" /etc/passwd | wc -l
#方法 2：
awk -f : '/bash$/{x++}end{print x}' /etc/passwd
(13) Backup MySQL table data
#!/bin/sh
source /etc/profile
dbName=mysql
tableName=db
echo [`date +'%Y-%m-%d %H:%M:%S'`]' start loading data...'
mysql -uroot -proot -P3306 ${dbName} -e "LOAD DATA LOCAL INFILE '# /home/wenmin/wenxing.txt' INTO TABLE ${tableName} FIELDS TERMINATED BY ';'"
echo [`date +'%Y-%m-%d %H:%M:%S'`]' end loading data...'
exit
EOF
(14) Use an infinite loop to display the packet traffic sent by the eth0 network card in real time
#!/bin/bash
# 使用死循环实时显示 eth0 网卡发送的数据包流量
while :
do
echo '本地网卡 ens33 流量信息如下：'
ifconfig ens33 | grep "RX pack" | awk '{print $5}'
ifconfig ens33 | grep "TX pack" | awk '{print $5}'
sleep 1
done
(15) Write a script to test which hosts in the entire network segment of 192.168.4.0/24 are powered on and which hosts are powered off
#!/bin/bash
# 编写脚本测试 192.168.4.0/24 整个网段中哪些主机处于开机状态,哪些主机处于关机
# 状态(for 版本)
for i in {1..254}
do
# 每隔0.3秒ping一次，一共ping2次，并以1毫秒为单位设置ping的超时时间
ping -c 2 -i 0.3 -W 1 192.168.1.$i &>/dev/null
if [ $? -eq 0 ];then
echo "192.168.1.$i is up"
else
echo "192.168.1.$i is down"
fi
done
(16) Write script: Prompt the user to enter the user name and password, and the script will automatically create the corresponding account and configure the password. if the user
#!/bin/bash
# 编写脚本:提示用户输入用户名和密码,脚本自动创建相应的账户及配置密码。如果用户
# 不输入账户名,则提示必须输入账户名并退出脚本;如果用户不输入密码,则统一使用默
# 认的 123456 作为默认密码。
read -p "请输入用户名：" user
#使用‐z 可以判断一个变量是否为空,如果为空,提示用户必须输入账户名,并退出脚本,退出码为 2
#没有输入用户名脚本退出后,使用$?查看的返回码为 2
if [ -z $user ]; then
echo " 您不需要输入账户名"
exit 2
fi
#使用 stty ‐echo 关闭 shell 的回显功能
#使用 stty echo 打开 shell 的回显功能
stty -echo
read -p "请输入密码：" pass
stty echo
pass=${pass:-123456}
useradd "$user"
echo "$pass" | passwd --stdin "$user"
(17) Use the script to sort the three input integers
#!/bin/bash
# 依次提示用户输入 3 个整数,脚本根据数字大小依次排序输出 3 个数字
read -p " 请输入一个整数：" num1
read -p " 请输入一个整数：" num2
read -p " 请输入一个整数: " num3
# 不管谁大谁小,最后都打印 echo "$num1,$num2,$num3"
# num1 中永远存最小的值,num2 中永远存中间值,num3 永远存最大值
# 如果输入的不是这样的顺序,则改变数的存储顺序,如:可以将 num1 和 num2 的值对调
tmp=0
# 如果 num1 大于 num2,就把 num1 和和 num2 的值对调,确保 num1 变量中存的是最小值
if [ $num1 -gt $num2 ];then
tmp=$num1
num1=$num2
num2=tmp
fi
# 如果 num1 大于 num3,就把 num1 和 num3 对调,确保 num1 变量中存的是最小值
if [ $num1 -gt $num3 ];then
tmp=$num1
num1=$num3
num3=$tmp
fi
# 如果 num2 大于 num3,就把 num2 和 num3 对调,确保 num2 变量中存的是最小值
if [ $num2 -gt $num3 ];then
tmp=$num2
num2=$num3
num3=$tmp
fi
echo "排序后数据（从小到大）为：$num1,$num2,$num3"
(18) According to the current time of the computer, the greeting is returned, and the script can be set to start at boot
#!/bin/bash
# 根据计算机当前时间,返回问候语,可以将该脚本设置为开机启动
# 00‐12 点为早晨,12‐18 点为下午,18‐24 点为晚上
# 使用 date 命令获取时间后,if 判断时间的区间,确定问候语内容
tm=$(date +%H)
if [ $tm -le 12 ];then
msg="Good Morning $USER"
elif [ $tm -gt 12 -a $tm -le 18 ];then
msg="Good Afternoon $USER"
else
msg="Good Night $USER"
fi
echo "当前时间是:$(date +"%Y‐%m‐%d %H:%M:%S")"
echo -e "\033[34m$msg\033[0m"
(19) Write I lov cls to the txt file
#!/bin/bash
cd /home/wenmin/
touch wenxing.txt
echo "I lov cls" >>wenxing.txt
(20) Script writing for loop judgment
#!/bin/bash
s=0;
for((i=1;i<100;i++))
do
s=$[$s+$i]
done
echo $s
r=0;
a=0;
b=0;
for((x=1;x<9;x++))
do
a=$[$a+$x]
echo $x
done
for((y=1;y<9;y++))
do
b=$[$b+$y]
echo $y
done
echo $r=$[$a+$b]
(21) Script writing for loop judgment
#!/bin/bash
for i in "$*"
do
echo "wenmin xihuan $i"
done
for j in "$@"
do
echo "wenmin xihuan $j"
done
(22) The script uses the tar command to back up all log files under /var/log every 5 weeks
#!/bin/bash
# 每周 5 使用 tar 命令备份/var/log 下的所有日志文件
# vim /root/logbak.sh
# 编写备份脚本,备份后的文件名包含日期标签,防止后面的备份将前面的备份数据覆盖
# 注意 date 命令需要使用反引号括起来,反引号在键盘<tab>键上面
tar -czf log-`date +%Y%m%d`.tar.gz /var/log
# crontab -e #编写计划任务，执行备份脚本
00 03 * * 5 /home/wenmin/datas/logbak.sh
(23) Scripting summation function operation function xx()
#!/bin/bash
function sum()
{
s=0;
s=$[$1+$2]
echo $s
}
read -p "input your parameter " p1
read -p "input your parameter " p2
sum $p1 $p2
function multi()
{
r=0;
r=$[$1/$2]
echo $r
}
read -p "input your parameter " x1
read -p "input your parameter " x2
multi $x1 $x2
v1=1
v2=2
let v3=$v1+$v2
echo $v3
(24) Scripting case — esac branch structure expression
#!/bin/bash
case $1 in
1)
echo "wenmin "
;;
2)
echo "wenxing "
;;
3)
echo "wemchang "
;;
4)
echo "yijun"
;;
5)
echo "sinian"
;;
6)
echo "sikeng"
;;
7)
echo "yanna"
;;
*)
echo "danlian"
;;
esac
(25) # Define the address of the page to be monitored, restart or maintain the tomcat status
#!/bin/sh
# function:自动监控tomcat进程，挂了就执行重启操作
# author:huanghong
# DEFINE
# 获取tomcat PPID
TomcatID=$(ps -ef |grep tomcat |grep -w 'apache-tomcat-7.0.75'|grep -v 'grep'|awk '{print $2}')
# tomcat_startup
StartTomcat=/opt/apache-tomcat-7.0.75/bin/startup.sh
#TomcatCache=/usr/apache-tomcat-5.5.23/work
# 定义要监控的页面地址
WebUrl=http://192.168.254.118:8080/
# 日志输出
GetPageInfo=/dev/null
TomcatMonitorLog=/tmp/TomcatMonitor.log
Monitor()
{
echo "[info]开始监控tomcat...[$(date +'%F %H:%M:%S')]"
if [ $TomcatID ]
then
echo "[info]tomcat进程ID为:$TomcatID."
# 获取返回状态码
TomcatServiceCode=$(curl -s -o $GetPageInfo -m 10 --connect-timeout 10 $WebUrl -w %{http_code})
if [ $TomcatServiceCode -eq 200 ];then
echo "[info]返回码为$TomcatServiceCode,tomcat启动成功,页面正常."
else
echo "[error]访问出错，状态码为$TomcatServiceCode,错误日志已输出到$GetPageInfo"
echo "[error]开始重启tomcat"
kill -9 $TomcatID # 杀掉原tomcat进程
sleep 3
#rm -rf $TomcatCache # 清理tomcat缓存
$StartTomcat
fi
else
echo "[error]进程不存在!tomcat自动重启..."
echo "[info]$StartTomcat,请稍候......"
#rm -rf $TomcatCache
$StartTomcat
fi
echo "------------------------------"
}
Monitor>>$TomcatMonitorLog
(26) Create a Linux system account and password through location variables
#!/bin/bash
# 通过位置变量创建Linux 系统账户及密码
# $1 是执行脚本的第一个参数，$2 是执行脚本的第二个参数
useradd "$1"
echo "$2" | passwd --stdin "$1"
(27) Pass in and get the number of variables and print
#!/bin/bash
echo "$0 $1 $2 $3" // 传入三个参数
echo $# //获取传入参数的数量
echo $@ //打印获取传入参数
echo $* //打印获取传入参数
(28) Real-time monitoring of the local memory and the remaining space of the hard disk. When the remaining memory is less than 500M and the remaining space of the root partition is less than 1000M, an alarm email will be sent to the root administrator
#!/bin/bash
# 实时监控本机内存和硬盘剩余空间,剩余内存小于500M、根分区剩余空间小于1000M时,发送报警邮件给root管理员
# 提取根分区剩余空间
disk_size=$(df / | awk '/\//{print $4}')
# 提取内存剩余空空间
mem_size=$(free | awk '/Mem/{print $4}')
while :
do
# 注意内存和磁盘提取的空间大小都是以 Kb 为单位
if [ $disk_size -le 512000 -a $mem_size -le 1024000 ]
then
mail ‐s "Warning" root <<EOF
Insufficient resources,资源不足
EOF
fi
done
(29) Check whether the corresponding file exists in the specified directory
#!/bin/bash
if [ -f /home/wenmin/datas ]
then
echo "File exists"
fi
(30) Script definition while loop statement
#!/bin/bash
if [ -f /home/wenmin/datas ]
then
echo "File exists"
fi
[root@rich datas]# cat while.sh
#!/bin/bash
s=0
i=1
while [ $i -le 100 ]
do
s=$[$s + $i]
i=$[$i + 1]
done
echo $s
echo $i
(31) One-click deployment of LNMP (RPM package version)
#!/bin/bash
# 一键部署 LNMP(RPM 包版本)
# 使用 yum 安装部署 LNMP,需要提前配置好 yum 源,否则该脚本会失败
# 本脚本使用于 centos7.2 或 RHEL7.2
yum -y install httpd
yum -y install mariadb mariadb-devel mariadb-server
yum -y install php php-mysql
systemctl start httpd mariadb
systemctl enable httpd mariadb
(32) Read the incoming parameters of the console
#!/bin/bash
read -t 7 -p "input your name " NAME
echo $NAME
read -t 11 -p "input you age " AGE
echo $AGE
read -t 15 -p "input your friend " FRIEND
echo $FRIEND
read -t 16 -p "input your love " LOVE
echo $LOVE
(33) Script realizes copying
#!/bin/bash
cp $1 $2
(34) The script realizes the judgment of whether the file exists or not
#!/bin/bash
if [ -f file.txt ];then
echo "文件存在"
else
echo "文件不存在"
fi