images\cherry_red.png1 Linux运维学习笔记
      images\cherry_blue.png1.1 基本操作命令
         images\cherry_orange.png1.1.1 权限管理
            images\cherry_cyan.png1.1.1.1 chmod
            images\cherry_cyan.png1.1.1.2 chown
            images\cherry_cyan.png1.1.1.3 setfacl
            images\cherry_cyan.png1.1.1.4 chattr
         images\cherry_orange.png1.1.2 用户管理
            images\cherry_cyan.png1.1.2.1 useradd(添加用户)
            images\cherry_cyan.png1.1.2.2 passwd(修改用户密码)
            images\cherry_cyan.png1.1.2.3 userdel(删除用户角色)
            images\cherry_cyan.png1.1.2.4 usermod(修改用户信息)
            images\cherry_cyan.png1.1.2.5 groupadd(添加工作组)
            images\cherry_cyan.png1.1.2.6 groupdel(删除工作组)
         images\cherry_orange.png1.1.3 文件管理
            images\cherry_cyan.png1.1.3.1 cat
            images\cherry_cyan.png1.1.3.2 mv
            images\cherry_cyan.png1.1.3.3 scp,rsync文件传输
               images\cherry_orange_dark.png1.1.3.3.1 scp
            images\cherry_cyan.png1.1.3.4 rz
            images\cherry_cyan.png1.1.3.5 awk
               images\cherry_orange_dark.png1.1.3.5.1 案例
            images\cherry_cyan.png1.1.3.6 cp复制
            images\cherry_cyan.png1.1.3.7 more
            images\cherry_cyan.png1.1.3.8 less
            images\cherry_cyan.png1.1.3.9 mkdir
            images\cherry_cyan.png1.1.3.10 diff
            images\cherry_cyan.png1.1.3.11 head
            images\cherry_cyan.png1.1.3.12 tail
            images\cherry_cyan.png1.1.3.13 sed
            images\cherry_cyan.png1.1.3.14 sort
            images\cherry_cyan.png1.1.3.15 uniq (去重语句)
            images\cherry_cyan.png1.1.3.16 grep
               images\cherry_orange_dark.png1.1.3.16.1 grep(2)
            images\cherry_cyan.png1.1.3.17 xargs
            images\cherry_cyan.png1.1.3.18 tr
            images\cherry_cyan.png1.1.3.19 cut
            images\cherry_cyan.png1.1.3.20 od
            images\cherry_cyan.png1.1.3.21 dos2unix
            images\cherry_cyan.png1.1.3.22 cpio
            images\cherry_cyan.png1.1.3.23 tee
            images\cherry_cyan.png1.1.3.24 column
            images\cherry_cyan.png1.1.3.25 swapon
         images\cherry_orange.png1.1.4 软件包管理
            images\cherry_cyan.png1.1.4.1 yarn
            images\cherry_cyan.png1.1.4.2 zip
         images\cherry_orange.png1.1.5 备份策略
            images\cherry_cyan.png1.1.5.1 tar
            images\cherry_cyan.png1.1.5.2 cp
      images\cherry_blue.png1.2 系统工作常用命令
         images\cherry_orange.png1.2.1 ab(压力测试)
            images\cherry_cyan.png1.2.1.1 ab常见问题
         images\cherry_orange.png1.2.2 nohup
            images\cherry_cyan.png1.2.2.1 bg fg
         images\cherry_orange.png1.2.3 crontab
         images\cherry_orange.png1.2.4 find
            images\cherry_cyan.png1.2.4.1 find
         images\cherry_orange.png1.2.5 tcpdump
         images\cherry_orange.png1.2.6 ifconfig
         images\cherry_orange.png1.2.7 netstat(网络通信情况)
         images\cherry_orange.png1.2.8 ps (查看系统进程)
         images\cherry_orange.png1.2.9 top (系统运维状态)
         images\cherry_orange.png1.2.10 alias
         images\cherry_orange.png1.2.11 pidof
         images\cherry_orange.png1.2.12 kill与killall与pkill
         images\cherry_orange.png1.2.13 uptime(系统负载信息)
         images\cherry_orange.png1.2.14 free(系统内存情况)
         images\cherry_orange.png1.2.15 last(登陆日志)
         images\cherry_orange.png1.2.16 fdisk(磁盘分区)
         images\cherry_orange.png1.2.17 strace
         images\cherry_orange.png1.2.18 lsmod
         images\cherry_orange.png1.2.19 ssh
            images\cherry_cyan.png1.2.19.1 sshpass
         images\cherry_orange.png1.2.20 ftp (sftp)
         images\cherry_orange.png1.2.21 du
         images\cherry_orange.png1.2.22 umask(文件权限)
         images\cherry_orange.png1.2.23 df (磁盘占用情况)
         images\cherry_orange.png1.2.24 curl
         images\cherry_orange.png1.2.25 date
         images\cherry_orange.png1.2.26 lsof
         images\cherry_orange.png1.2.27 chrony
         images\cherry_orange.png1.2.28 cpu运行状态
         images\cherry_orange.png1.2.29 lshw
         images\cherry_orange.png1.2.30 vim
         images\cherry_orange.png1.2.31 lsb_release -a (系统版本信息)
      images\cherry_blue.png1.3 网络基础
         images\cherry_orange.png1.3.1 ifconfig
         images\cherry_orange.png1.3.2 route
         images\cherry_orange.png1.3.3 nslookup
         images\cherry_orange.png1.3.4 ping网关
         images\cherry_orange.png1.3.5 ISO/OSI七层模型
         images\cherry_orange.png1.3.6 TCP/IP三次握手(四次挥手)
            images\cherry_cyan.png1.3.6.1 三次握手
            images\cherry_cyan.png1.3.6.2 四次挥手
         images\cherry_orange.png1.3.7 IP地址网段(可用IP地址)(广播地址)
         images\cherry_orange.png1.3.8 网络连接数
         images\cherry_orange.png1.3.9 mtr
         images\cherry_orange.png1.3.10 ip
      images\cherry_blue.png1.4 系统管理类
         images\cherry_orange.png1.4.1 进程与线程
            images\cherry_cyan.png1.4.1.1 pstree
         images\cherry_orange.png1.4.2 系统安全
            images\cherry_cyan.png1.4.2.1 记录一次远程挖矿病毒
            images\cherry_cyan.png1.4.2.2 漏洞修补
         images\cherry_orange.png1.4.3 nfs远程挂载
            images\cherry_cyan.png1.4.3.1 nfs自动挂载
         images\cherry_orange.png1.4.4 查询系统用户登录情况
         images\cherry_orange.png1.4.5 权限优化
         images\cherry_orange.png1.4.6 备份策略
         images\cherry_orange.png1.4.7 Raid(磁盘阵列)
         images\cherry_orange.png1.4.8 资源查看(监控)
            images\cherry_cyan.png1.4.8.1 dstat(网络监控)
         images\cherry_orange.png1.4.9 启动流程
         images\cherry_orange.png1.4.10 系统优化
         images\cherry_orange.png1.4.11 cpu
      images\cherry_blue.png1.5 Shell编程
         images\cherry_orange.png1.5.1 数组类型
         images\cherry_orange.png1.5.2 if 条件判断
         images\cherry_orange.png1.5.3 for
         images\cherry_orange.png1.5.4 文本截取
         images\cherry_orange.png1.5.5 随机字符串
         images\cherry_orange.png1.5.6 网站检测
            images\cherry_cyan.png1.5.6.1 nmap
         images\cherry_orange.png1.5.7 Debug
         images\cherry_orange.png1.5.8 declare
      images\cherry_blue.png1.6 网络服务类
         images\cherry_orange.png1.6.1 网关
         images\cherry_orange.png1.6.2 SSH服务
         images\cherry_orange.png1.6.3 DHCP + FTP
         images\cherry_orange.png1.6.4 DNS服务
            images\cherry_cyan.png1.6.4.1 智能DNS
         images\cherry_orange.png1.6.5 Apache配置
            images\cherry_cyan.png1.6.5.1 Apache 三种工作模式
         images\cherry_orange.png1.6.6 Apache优化
            images\cherry_cyan.png1.6.6.1 CDN
         images\cherry_orange.png1.6.7 Nginx配置
            images\cherry_cyan.png1.6.7.1 nginx开启SSL证书
            images\cherry_cyan.png1.6.7.2 Session一致性解决方案
            images\cherry_cyan.png1.6.7.3 异步非阻塞方式
            images\cherry_cyan.png1.6.7.4 Nginx反向代理配置出现问题
            images\cherry_cyan.png1.6.7.5 nginx 负载均衡算法
            images\cherry_cyan.png1.6.7.6 nginx status
         images\cherry_orange.png1.6.8 Nginx优化
            images\cherry_cyan.png1.6.8.1 Nginx请求PHP(Tomcat)过程
            images\cherry_cyan.png1.6.8.2 gzip压缩
            images\cherry_cyan.png1.6.8.3 缓存优化
            images\cherry_cyan.png1.6.8.4 反向代理
         images\cherry_orange.png1.6.9 http状态码
      images\cherry_blue.png1.7 数据库管理类
         images\cherry_orange.png1.7.1 集群部署(Amoeba)
         images\cherry_orange.png1.7.2 索引
         images\cherry_orange.png1.7.3 误操作Drop语句如何解决?
         images\cherry_orange.png1.7.4 Redis(缓存数据库)
            images\cherry_cyan.png1.7.4.1 Redis_
      images\cherry_blue.png1.8 Good Luck
      images\cherry_blue.png1.9 Linux(实际工作可能常用命令)
      images\cherry_blue.png1.10 LeetCode(Bash)
         images\cherry_orange.png1.10.1 统计词频
         images\cherry_orange.png1.10.2 有效电话号码
   images\cherry_red.png2 三剑客
      images\cherry_blue.png2.1 正则表达式
         images\cherry_orange.png2.1.1 扩展正则表达式
      images\cherry_blue.png2.2 grep(...过滤)
      images\cherry_blue.png2.3 sed(...替换)
         images\cherry_orange.png2.3.1 sed删除,增加
         images\cherry_orange.png2.3.2 sed 替换
      images\cherry_blue.png2.4 awk(...取列统计)
         images\cherry_orange.png2.4.1 awk模式匹配
         images\cherry_orange.png2.4.2 awk数组
nohup 英文全称 no hang up(不挂起),用于在系统后台不挂断地运行命令,退出终端不会影响程序的运行。
nohup 命令,在默认情况下(非重定向时),会输出一个名叫 nohup.out 的文件到当前目录下,
如果当前目录的 nohup.out 文件不可写,输出重定向到 $HOME/nohup.out 文件中。



参数说明:

Command:要执行的命令。
Arg:一些参数,可以指定输出文件。
&:让命令在后台执行,终端退出后命令仍旧执行。


实例
以下命令在后台执行 root 目录下的 runoob.sh 脚本:
nohup /root/runoob.sh &在终端如果看到以下输出说明运行成功:
appending output to nohup.out这时我们打开 root 目录 可以看到生成了 nohup.out 文件。
如果要停止运行,你需要使用以下命令查找到 nohup 运行脚本到 PID,然后使用 kill 命令来删除:
ps -aux | grep "runoob.sh" 参数说明:
• a : 显示所有程序
• u : 以用户为主的格式来显示
• x : 显示所有程序,不区分终端机


另外也可以使用 ps -def | grep "runoob.sh" 命令来查找。
找到 PID 后,就可以使用 kill PID 来删除。
kill -9 进程号PID以下命令在后台执行 root 目录下的 runoob.sh 脚本,并重定向输入到 runoob.log 文件:
nohup /root/runoob.sh > runoob.log 2>&1 &


2>&1 解释:
将标准错误 2 重定向到标准输出 &1 ,标准输出 &1 再被重定向输入到 runoob.log 文件中。
• 0 – stdin (standard input,标准输入)
• 1 – stdout (standard output,标准输出)
• 2 – stderr (standard error,标准错误输出)


#!/bin/bash

export PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin
. /etc/profile
. ~/.bash_profile
source /etc/profile

netstat -nlpt | grep -w "3000" & >>/dev/null

if [ $? -eq 0 ];then
cd /gaogaotwo/study.zmide.com-0b867a1d26dd3b9d44a59630d3f38bac688a639d && nohup yarn start >/dev/null 2>&1 &
if [ $? -eq 0 ];then
echo '启动成功!'
fi
fi