練習題(不定時補充)

** 截取連續多個列內容 **linux

[root@linux01 ~]# awk -F: '{for(i=3;i<NF;i++) printf $i":";print $NF}' /etc/passwd    -->經過循環解決多個列的選取
0:0:root:/root:/bin/bash
1:1:bin:/bin:/sbin/nologin
2:2:daemon:/sbin:/sbin/nologin
3:4:adm:/var/adm:/sbin/nologin
4:7:lp:/var/spool/lpd:/sbin/nologin
5:0:sync:/sbin:/bin/sync
6:0:shutdown:/sbin:/sbin/shutdown
7:0:halt:/sbin:/sbin/halt
8:12:mail:/var/spool/mail:/sbin/nologin
11:0:operator:/root:/sbin/nologin
12:100:games:/usr/games:/sbin/nologin
14:50:FTP User:/var/ftp:/sbin/nologin
99:99:Nobody:/:/sbin/nologin
999:997:systemd Bus Proxy:/:/sbin/nologin
192:192:systemd Network Management:/:/sbin/nologin
81:81:System message bus:/:/sbin/nologin
998:996:User for polkitd:/:/sbin/nologin
59:59:Account used by the trousers package to sandbox the tcsd daemon:/dev/null:/sbin/nologin
89:89::/var/spool/postfix:/sbin/nologin
74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin
997:995::/var/lib/chrony:/sbin/nologin
996:994:Jenkins Automation Server:/var/lib/jenkins:/bin/false
995:992::/var/opt/gitlab/nginx:/bin/false
994:991::/var/opt/gitlab:/bin/sh
993:990::/var/opt/gitlab/redis:/bin/false
992:989::/var/opt/gitlab/postgresql:/bin/sh
991:988::/var/opt/gitlab/prometheus:/bin/sh
1000:1000::/home/virftp:/sbin/nologin
72:72::/:/sbin/nologin

** 打印當前IP地址 **nginx

[root@linux01 ~]# ifconfig
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.111.128  netmask 255.255.255.0  broadcast 192.168.111.255
        inet6 fe80::9f24:73fe:b3f8:5c5c  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:2d:de:67  txqueuelen 1000  (Ethernet)
        RX packets 65  bytes 7705 (7.5 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 85  bytes 9829 (9.5 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1  (Local Loopback)
        RX packets 238  bytes 132906 (129.7 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 238  bytes 132906 (129.7 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
[root@linux01 ~]# ifconfig|awk '/ens/{print $1;getline;print $2}'|xargs
ens33: 192.168.111.128

** 把多個偶數行內容單行顯示 **git

[root@linux01 ~]# seq 11|sed -n 'n;p'|xargs    -->單行顯示內容,沒有符號間隔
2 4 6 8 10
[root@linux01 ~]# seq 11|sed -n 'n;p'|sed ':a;N;s/\n/,/;ta'    -->單行顯示內容,有符號間隔
2,4,6,8,10

** 查看鏈接某服務端口最多的的IP地址 **redis

[root@linux01 ~]# netstat -ntu|grep -w 8080|awk '{print $5}'|awk -F: '{print $1}'|sort|uniq -c|sort -nr
      4 127.0.0.1

** TCP各類狀態列表 **sql

[root@linux01 ~]# netstat -nt|grep -e 127.0.0.1 -e 0.0.0.0 -e ::: -v|grep tcp|awk '{print $6}'|sort|uniq -c|sort -nr
     12 TIME_WAIT
      2 ESTABLISHED

** 查看nginx進程數，若是接近預設值，說明不夠用，須要增長 **centos

[root@linux01 ~]# netstat -anpo|grep nginx|wc -l
6

** centos查看系統cpu個數、核心數、線程數 **bash

[root@linux01 ~]# grep "processor" /proc/cpuinfo|sort -u|wc -l    -->線程數
1
[root@linux01 ~]# grep "physical id" /proc/cpuinfo|sort -u|wc -l    -->CPU個數
1
[root@linux01 ~]# grep "core id" /proc/cpuinfo|sort -u|wc -l          -->核心數
1

** 查看系統相關信息 **ssh

[root@linux01 ~]# grep MemTotal /proc/meminfo    -->查看內存方法
MemTotal:        1867024 kB
[root@linux01 ~]# cat /etc/redhat-release    -->centos查看系統版本
CentOS Linux release 7.4.1708 (Core) 
[root@linux01 ~]# cat /proc/version            -->查看centos內核的版本
Linux version 3.10.0-693.5.2.el7.x86_64 (builder@kbuilder.dev.centos.org) (gcc version 4.8.5 20150623 (Red Hat 4.8.5-16) (GCC) ) #1 SMP Fri Oct 20 20:32:50 UTC 2017
[root@linux01 ~]# getconf LONG_BIT        -->查看系統是64位仍是32位
64