Linux日常小技巧shell腳本

在工作中我們常用shell腳本處理一些問題，這裡整理了一些工作中常用的簡單shell腳本。

1. 定時備份檔案

#!/bin/bash
backup_dir="/data1/backup"
src_dir="/data1/app"
date_time=$(date +%Y%m%d_%H%M%S)
tar -czvf ${backup_dir}/${date_time}.tar.gz ${src_dir}
           

1. 批量更改檔案字尾名

#!/bin/bash
for file in *.jpg
do
    mv "$file" "${file%jpg}png"
done
           

1. 執行多個任務并發運作

#!/bin/bash
task1 &
task2 &
task3 &
wait
echo "All tasks completed!"
           

1. 根據檔案大小清理指定目錄

#!/bin/bash
dir="/data/log"
max_size="50M"
find ${dir} -type f -size +${max_size} -delete           

1. 自動解壓檔案并删除原檔案

#!/bin/bash
for file in *.zip
do
    unzip ${file} && rm ${file}
done
           

1. 監控伺服器記憶體使用情況

#!/bin/bash
total_mem=$(free -m | awk 'NR==2{print $2}')
used_mem=$(free -m | awk 'NR==2{print $3}')
percent=$(bc -l <<< "scale=2;${used_mem}/${total_mem}*100")
if (( $(echo "${percent} > 80" | bc -l) )); then
    echo "Memory usage exceeds 80%!"
    # Send notification email or alert
fi
           

1. 傳參數啟動java項目

#! /bin/bash

#jar包的檔案路徑
APP_NAME="$2"
PORT=9086

help(){
	echo "====================================="
	echo "項目位址： ${APP_NAME}"
	echo "你可以使用如下參數進行操作"
	echo "-status  -檢視目前項目運作狀态"
	echo "-start   -啟動目前項目"
	echo "-stop    -停止目前項目"
	echo "-restart -重新開機目前項目" 
	echo "====================================="
}

#查找jar包程序，排除grep，程序資訊的第二個字段：即程序号
pid=`netstat -apn |grep $PORT |awk '{print $7}' |cut -d/ -f 1`

status(){
	if [ -z "$pid" ]
		then 
			echo "項目已停止運作"
	else
			echo "項目正在運作..."
                        echo "程序号:$pid"
                        echo "項目名稱:$APP_NAME"
	fi
}

start(){
	if [ -z "$pid" ]
		then 
			echo "正在啟動..."
			nohup java -Dspring.profiles.active=prod -jar $APP_NAME  >/dev/null 2>nohup &
                        tail -f -n 200 nohup.out
		else
			echo "項目正在運作中或端口被占用"
                        echo "程序号:$pid"
	fi
}

stop(){
	if [ -z "$pid" ] 
		then 
			echo "項目已經停止"
	else
			kill -9 $pid
			echo "完成停止項目"
	fi
}

restart(){
	if [ -z "$pid" ]
		then
			echo "項目未啟動"
	else
		kill -9 $pid
	fi
	sleep 5
	start
	echo "完成項目重新開機"
}

case "$1" in
	"-status")
	status
	;;
	"-start")
	start
	;;
	"-stop")
	stop
	;;
	"-restart")
	restart
	;;
        "-help")
        help
        ;;
	*)
	help
	;;
esac
           

1. 自動備份資料庫

#!/bin/bash
db_host="127.0.0.1"
db_port="3306"
db_user="root"
db_pass="password"
db_name="mydb"
backup_dir="/data/backup"
date_time=$(date +%Y%m%d_%H%M%S)
mysqldump -h${db_host} -P${db_port} -u${db_user} -p${db_pass} ${db_name} | gzip > ${backup_dir}/${db_name}-${date_time}.sql.gz
           

1. 掃描伺服器端口并發送報告郵件

#!/bin/bash
host_ip="127.0.0.1"
report_file="/tmp/port_scan_report.txt"
for port in {1..65535}
do
    timeout 1 bash -c "echo >/dev/tcp/${host_ip}/${port}" 2>/dev/null && echo "${host_ip}:${port} is open" >> ${report_file}
done
# Send report email
mail -s "Port scan report" [email protected] < ${report_file}
           

1. 自動更新伺服器軟體包并重新開機服務

#!/bin/bash
yum update -y
service nginx restart
service mysql restart
service tomcat restart           

11.自動清理過期日志檔案

#!/bin/bash
log_dir="/data/log"
max_age="30" # days
find ${log_dir} -type f -mtime +${max_age} -delete
           

12.自動備份MySQL資料庫并删除舊備份

#!/bin/bash
db_user="root"
db_pass="password"
backup_dir="/data/backup"
date_time=$(date +%Y%m%d_%H%M%S)
db_list=$(mysql -u${db_user} -p${db_pass} -e "show databases;" | grep -Ev "(Database|information_schema|performance_schema)")
for db in ${db_list}
do
    mysqldump -u${db_user} -p${db_pass} ${db} | gzip > ${backup_dir}/${db}-${date_time}.sql.gz
done
find ${backup_dir} -type f -name '*.gz' -mtime +7 -delete
           

13.批量重命名檔案名中的空格為下劃線

#!/bin/bash
for file in *\ *
do
    mv "${file}" "${file// /_}"
done
           

14.自動清理過期Docker鏡像及容器

#!/bin/bash
image_age="7" # days
container_age="2" # days
docker system prune -f
docker rmi $(docker images -q --filter "dangling=true") 2>/dev/null || true
docker container prune -f
docker ps -a | awk '/Exited/ {print $1}' | xargs docker rm
docker container ls -a -q --filter "status=exited" --filter "created<=$(( ${container_age} * 86400 ))" | xargs docker rm
           

15.自動壓縮指定目錄并上傳到遠端伺服器

#!/bin/bash
local_dir="/data/app"
backup_dir="/data/backup"
remote_host="192.168.1.100"
remote_port="22"
remote_user="root"
remote_dir="/backup"
ssh_key="/root/.ssh/id_rsa"
date_time=$(date +%Y%m%d_%H%M%S)
filename="${backup_dir}/app_${date_time}.tar.gz"
tar -czvf ${filename} ${local_dir}
scp -i ${ssh_key} -P ${remote_port} ${filename} ${remote_user}@${remote_host}:${remote_dir}
rm ${filename}
           

16.自動監控Nginx請求量及響應時間

#!/bin/bash
log_file="/var/log/nginx/access.log"
interval="60" # seconds
req_count=$(tail -n 100 ${log_file} | wc -l)
avg_resp_time=$(tail -n 100 ${log_file} | awk '{total+=$NF} END {print total/NR}')
if (( $(echo "${req_count} > 100" | bc -l) )); then
    echo "High request count: ${req_count}"
    # Send notification email or alert
fi
if (( $(echo "${avg_resp_time} > 1.0" | bc -l) )); then
    echo "High average response time: ${avg_resp_time}s"
    # Send notification email or alert
fi
           

17.定時同步檔案到遠端伺服器

#!/bin/bash
local_file="/data/app/myfile"
remote_host="192.168.1.100"
remote_port="22"
remote_user="root"
remote_file="/data/files/myfile"
ssh_key="/root/.ssh/id_rsa"
md5sum_local=$(md5sum ${local_file} | awk '{print $1}')
md5sum_remote=$(ssh -i ${ssh_key} -p ${remote_port} ${remote_user}@${remote_host} "md5sum ${remote_file} 2>/dev/null" | awk '{print $1}')
if [ "${md5sum_local}" != "${md5sum_remote}" ]; then
    scp -i ${ssh_key} -P ${remote_port} ${local_file} ${remote_user}@${remote_host}:${remote_file}
fi
           

18.自動備份MongoDB資料庫并上傳到遠端伺服器

#!/bin/bash
db_name="mydb"
backup_dir="/data/backup"
remote_host="192.168.1.100"
remote_port="22"
remote_user="root"
remote_dir="/backup"
ssh_key="/root/.ssh/id_rsa"
date_time=$(date +%Y%m%d_%H%M%S)
filename="${backup_dir}/${db_name}_${date_time}.tar.gz"
mongodump --gzip --archive=${filename} --db=${db_name}
scp -i ${ssh_key} -P ${remote_port} ${filename} ${remote_user}@${remote_host}:${remote_dir}
rm ${filename}
           

19.批量更新Docker鏡像

#!/bin/bash
docker-compose pull
docker-compose up -d
           

20自動備份檔案到FTP伺服器并删除舊備份

#!/bin/bash
local_dir="/data/app"
backup_dir="/data/backup"
remote_host="ftp.example.com"
remote_user="backup_user"
remote_pass="backup_password"
remote_dir="/backup/files"
filename="${backup_dir}/app_$(date +%Y%m%d_%H%M%S).tar.gz"
tar -czvf ${filename} ${local_dir}
ncftp -u ${remote_user} -p ${remote_pass} ${remote_host} <<EOF
cd ${remote_dir}
put ${filename}
ls -t | awk 'NR>7' | xargs rm
quit
EOF
rm ${filename}