shell基本语法
Posted luchuangao
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作业一:整理博客,内容包含awk、变量、运算符、if多分支
作业二:awk文本处理
1、打印uid在30~40范围内的用户名
[[email protected] ~]# awk -F: ‘$3>=30 && $3<=40{print $1}‘ /etc/passwd rpc ntp
2、打印第5-10行的行号和用户名
[[email protected] ~]# awk -F: ‘NR>=5 && NR<=10{print NR,"-------",$1}‘ /etc/passwd 5 ------- lp 6 ------- sync 7 ------- shutdown 8 ------- halt 9 ------- mail 10 ------- operator
3、打印奇数行
[[email protected] ~]# awk ‘(NR%2){print NR,"----",$0}‘ test 1 ---- root:x:0:0:root:/root:/bin/bash 3 ---- nginx:x:991:547:Nginx web server:/var/lib/nginx:/sbin/nologin 5 ---- abominate:x:1010:1011::/home/abominate:/bin/bash 7 ---- atomize:x:1012:1013::/home/atomize:/bin/bash 9 ---- Wpq2222b:x:1014:1015::/home/Wpq2222b:/bin/bash 11 ---- egon666:x:1016:1017::/home/egon666:/bin/bash [[email protected] ~]#
4、打印偶数行
[[email protected] ~]# awk ‘!(NR%2){print NR,"----",$0}‘ test 2 ---- bin:x:1:1:bin:/bin:/sbin/nologin 4 ---- abominable:x:1009:1010::/home/abominable:/bin/bash 6 ---- anomie:x:1011:1012::/home/anomie:/bin/bash 8 ---- Alex213sb:x:1013:1014::/home/Alex213sb:/bin/bash 10 ---- yH438PIG:x:1015:1016::/home/yH438PIG:/bin/bash 12 ---- egon:x:1017:1002::/home/egon:/bin/bash
5、打印字段数大于5的行
[[email protected] ~]# awk -F: ‘NF>5{print $1,"-----",NF}‘ test root ----- 7 bin ----- 7 nginx ----- 7 abominable ----- 7 abominate ----- 7 anomie ----- 7 atomize ----- 7 Alex213sb ----- 7 Wpq2222b ----- 7 yH438PIG ----- 7 egon666 ----- 7 egon ----- 7
6、打印UID不等于GID的用户名
[[email protected] ~]# awk -F: ‘$3!=$4{print $3,"----",$4}‘ test 991 ---- 547 1009 ---- 1010 1010 ---- 1011 1011 ---- 1012 1012 ---- 1013 1013 ---- 1014 1014 ---- 1015 1015 ---- 1016 1016 ---- 1017 1017 ---- 1002
7、打印没有指定shell的用户
[[email protected] ~]# awk -F: ‘$NF!~/bash$/{print $0}‘ test bin:x:1:1:bin:/bin:/sbin/nologin nginx:x:991:547:Nginx web server:/var/lib/nginx:/sbin/nologin
作业三:shell脚本编写
1、自动部署、初始配置、并启动nginx反向代理服务
#!/bin/sh ngxStatus=`ps aux | grep -v grep |grep -c nginx` if [ -e /usr/sbin/nginx ];then echo "nginx already installed" exit 110 else yum install epel-release -y -q yum install gcc-* glibc-* openssl openssl-devel pcre pcre-devel zlib zlib-devel -y -q yum install nginx -y -q echo "install nginx successful" fi if [ -f /etc/nginx/nginx.conf ];then /bin/cp /etc/nginx/nginx.conf /etc/nginx/nginx.conf.bak sed -i ‘/^http/a\\t upstream luchuangao { \n\t server web01;\n\t server web02;\n\t server web03;\n\t }‘ /etc/nginx/nginx.conf sed -i ‘/^ location \/ {/a\\t\t proxy_pass http:\/\/luchuangao;‘ /etc/nginx/nginx.conf echo "Configuration successful" fi if [ $ngxStatus -lt 2 ];then systemctl start nginx echo "Start nginx successful" fi
2、自动部署、初始配置、并启动三台web
#!/bin/sh ngxStatus=`ps aux | grep -v grep |grep -c nginx` if [ -e /usr/sbin/nginx ];then echo "nginx already installed" exit 110 else yum install epel-release -y -q yum install gcc-* glibc-* openssl openssl-devel pcre pcre-devel zlib zlib-devel -y -q yum install nginx -y -q echo "install nginx successful" fi if [ -f /etc/nginx/nginx.conf ];then /bin/cp /etc/nginx/nginx.conf /etc/nginx/nginx.conf.bak sed -i ‘/^ location \/ {/a\\t\t root /data/www/html;\n\t\t index index.html;‘ /etc/nginx/nginx.conf mkdir -p /data/www/html echo `hostname` > /data/www/html/index.html echo "Configuration successful" fi if [ $ngxStatus -lt 2 ];then systemctl start nginx echo "Start nginx successful" fi
3、监控脚本:监控每台机器的内存使用率>70%,则输出报警信息
#!/bin/sh mem_use=`free | awk ‘NR==2{print $3}‘` mem_total=`free | awk ‘NR==2{print $2}‘` mem_per=`echo "scale=2;$mem_use/$mem_total"|bc -l |cut -d . -f2` if [ -e /usr/bin/bc ];then echo "bc already installed" else yum install bc -y -q echo "bc nginx successful" fi #if [ $mem_per -gt 70 ];then if (( $mem_per > 70 )); then echo "Warning free has not enough, now free is ${mem_per}%" else echo "Now free is ${mem_per}%" fi
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