前言
本文主要給大家介紹了關于linux系統用戶管理與grep正則表達式的相關內容，分享出來供大家參考學習，下面話不多說了，來一起看看詳細的介紹吧。
linux系統用戶管理與grep正則表達式
1、復制/etc/skel目錄為/home/tuser1，要求/home/tuser1及其內部文件的屬組和其它用戶均沒有任何訪問權限。
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[root@suywien ~]# cp -rpv /etc/skel/ /home/tuser1/‘/etc/skel/' -> ‘/home/tuser1/'‘/etc/skel/.mozilla' -> ‘/home/tuser1/.mozilla'‘/etc/skel/.mozilla/extensions' -> ‘/home/tuser1/.mozilla/extensions'‘/etc/skel/.mozilla/plugins' -> ‘/home/tuser1/.mozilla/plugins'‘/etc/skel/.bash_logout' -> ‘/home/tuser1/.bash_logout'‘/etc/skel/.bash_profile' -> ‘/home/tuser1/.bash_profile'‘/etc/skel/.bashrc' -> ‘/home/tuser1/.bashrc'[root@suywien ~]# useradd tuser -d /home/tuser1/useradd: warning: the home directory already exists.Not copying any file from skel directory into it.[root@suywien ~]# chmod -R go-rwx /home/tuser1/[root@suywien ~]# ll -d /home/tuser1/drwx------ 3 root root 74 Feb 12 03:04 /home/tuser1/ |
2、編輯/etc/group文件，添加組hadoop。
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[root@suywien ~]# vim /etc/group[root@suywien ~]# tail -1 /etc/grouphadoop:x:1029 |
3、手動編輯/etc/passwd文件新增一行，添加用戶hadoop，其基本組ID為hadoop組的id號；其家目錄為/home/hadoop。
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[root@suywien ~]# vim /etc/passwd[root@suywien ~]# tail -1 /etc/passwdhadoop:x:1029:1029::/home/hodoop/:/bin/bash |
4、復制/etc/skel目錄為/home/hadoop，要求修改hadoop目錄的屬組和其它用戶沒有任何訪問權限。
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[root@suywien ~]# cp -fpv /etc/skel/ /home/hadoopcp: omitting directory ‘/etc/skel/'[root@suywien ~]# cp -fpvR /etc/skel/ /home/hadoop‘/etc/skel/' -> ‘/home/hadoop'‘/etc/skel/.mozilla' -> ‘/home/hadoop/.mozilla'‘/etc/skel/.mozilla/extensions' -> ‘/home/hadoop/.mozilla/extensions'‘/etc/skel/.mozilla/plugins' -> ‘/home/hadoop/.mozilla/plugins'‘/etc/skel/.bash_logout' -> ‘/home/hadoop/.bash_logout'‘/etc/skel/.bash_profile' -> ‘/home/hadoop/.bash_profile'‘/etc/skel/.bashrc' -> ‘/home/hadoop/.bashrc'[root@suywien ~]# chmod go-rwx /home/hadoop/[root@suywien ~]# ls -ld /home/hadoop/drwx------ 3 root root 74 Feb 12 03:04 /home/hadoop/ |
5、修改/home/hadoop目錄及其內部所有文件的屬主為hadoop，屬組為hadoop。
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[root@suywien ~]# chown -R hadoop:hadoop /home/hadoop/[root@suywien ~]# ll -al /home/hadoop/total 16drwx------ 3 hadoop hadoop 74 Feb 12 03:04 .drwxr-xr-x. 10 root root 4096 Mar 25 10:14 ..-rw-r--r-- 1 hadoop hadoop 18 Nov 20 2015 .bash_logout-rw-r--r-- 1 hadoop hadoop 193 Nov 20 2015 .bash_profile-rw-r--r-- 1 hadoop hadoop 231 Nov 20 2015 .bashrcdrwxr-xr-x 4 hadoop hadoop 37 Feb 12 03:03 .mozilla |
6、顯示/proc/meminfo文件中以大寫或小寫S開頭的行；用兩種方式；
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[root@suywien ~]# grep ^[S,s] /proc/meminfo SwapCached: 0 kB SwapTotal: 2097148 kB SwapFree: 2097148 kB Shmem: 9100 kB Slab: 89476 kB SReclaimable: 53176 kB SUnreclaim: 36300 kB |
2、
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[root@suywien ~]# grep -i "^s" /proc/meminfo SwapCached: 0 kB SwapTotal: 2097148 kB SwapFree: 2097148 kB Shmem: 9100 kB |
7、顯示/etc/passwd文件中其默認shell為非/sbin/nologin的用戶；
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[root@suywien ~]# grep \/sbin\/nologin$ /etc/passwdbin:x:1:1:bin:/bin:/sbin/nologindaemon:x:2:2:daemon:/sbin:/sbin/nologinadm:x:3:4:adm:/var/adm:/sbin/nologinlp:x:4:7:lp:/var/spool/lpd:/sbin/nologinmail:x:8:12:mail:/var/spool/mail:/sbin/nologin...... |
8、顯示/etc/passwd文件中其默認shell為/bin/bash的用戶；
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[root@suywien ~]# grep \/bin\/bash /etc/passwdroot:x:0:0:root:/root:/bin/bashroo:x:1000:1000:root:/home/roo:/bin/bashgentoo:x:4001:4001::/home/gentoo:/bin/bashmageia:x:1100:1100::/home/linux:/bin/bashtuser:x:4003:4003::/home/tuser1/:/bin/bashhadoop:x:1029:1029::/home/hodoop/:/bin/bash |
9、找出/etc/passwd文件中的一位數或兩位數；
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[root@suywien ~]# grep "\<[0-9]\{2,3\}\>" /etc/passwdmail:x:8:12:mail:/var/spool/mail:/sbin/nologinoperator:x:11:0:operator:/root:/sbin/nologingames:x:12:100:games:/usr/games:/sbin/nologinftp:x:14:50:FTP User:/var/ftp:/sbin/nologin...... |
10、顯示/boot/grub/grub.conf中以至少一個空白字符開頭的行；
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[root@suywien ~]# grep "^[[:space:]]\+" /boot/grub2/grub.cfg load_env set default="${next_entry}" set next_entry= save_env next_entry set boot_once=true ...... |
11、顯示/etc/rc.d/rc.sysinit文件中以#開頭，后面跟至少一個空白字符，而后又有至少一個非空白字符的行；
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[root@suywien ~]# grep "^#[[:space:]]\+[^[:space:]]\+" /etc/rc.d/rc.local # THIS FILE IS ADDED FOR COMPATIBILITY PURPOSES# It is highly advisable to create own systemd services or udev rules# to run scripts during boot instead of using this file.# In contrast to previous versions due to parallel execution during boot# this script will NOT be run after all other services.# Please note that you must run 'chmod +x /etc/rc.d/rc.local' to ensure# that this script will be executed during boot. |
12、打出netstat -tan命令執行結果中以‘LISTEN'，后或跟空白字符結尾的行；
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[root@suywien ~]# netstat -tan | grep "LISTEN[[:space:]]*$"tcp 0 0 192.168.122.1:53 0.0.0.0:* LISTEN tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN tcp 0 0 127.0.0.1:631 0.0.0.0:* LISTEN tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN tcp6 0 0 :::22 :::* LISTEN tcp6 0 0 ::1:631 :::* LISTEN tcp6 0 0 ::1:25 :::* LISTEN |
13、添加用戶bash, testbash, basher, nologin (此一個用戶的shell為/sbin/nologin)，而后找出當前系統上其用戶名和默認shell相同的用戶的信息；
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[root@suywien ~]# useradd bash[root@suywien ~]# useradd basher[root@suywien ~]# useradd -s /sbin/nologin nologin[root@suywien ~]# grep -E "^([^:]+\>).*\1$" /etc/passwdsync:x:5:0:sync:/sbin:/bin/syncshutdown:x:6:0:shutdown:/sbin:/sbin/shutdownhalt:x:7:0:halt:/sbin:/sbin/haltbash:x:4004:4004::/home/bash:/bin/bashnologin:x:4006:4006::/home/nologin:/sbin/nologin |
總結
以上就是這篇文章的全部內容了，希望本文的內容對大家的學習或者工作具有一定的參考學習價值，如果有疑問大家可以留言交流，謝謝大家對服務器之家的支持。
原文鏈接：http://www.178linux.com/92876
