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。
[root@localhost ~]# cp -r /etc/skel /home/tuser1 [root@localhost ~]# ls -al /home/tuser1/skel total 12 drwxr-xr-x. 3 root root 74 Dec 22 04:09 . drwx------. 3 root root 17 Dec 22 04:09 .. -rw-r--r--. 1 root root 18 Dec 22 04:09 .bash_logout -rw-r--r--. 1 root root 193 Dec 22 04:09 .bash_profile -rw-r--r--. 1 root root 231 Dec 22 04:09 .bashrc drwxr-xr-x. 4 root root 37 Dec 22 04:09 .mozilla [root@localhost ~]# chmod -R go-rx /home/tuser1 [root@localhost ~]# ls -al /home/tuser1/skel total 12 drwx------. 3 root root 74 Dec 22 04:09 . drwx------. 3 root root 17 Dec 22 04:09 .. -rw-------. 1 root root 18 Dec 22 04:09 .bash_logout -rw-------. 1 root root 193 Dec 22 04:09 .bash_profile -rw-------. 1 root root 231 Dec 22 04:09 .bashrc drwx------. 4 root root 37 Dec 22 04:09 .mozilla [root@localhost ~]#
2、編輯/etc/group文件，添加組hadoop。
[root@localhost etc]# vim /etc/group admins:x:5035:slackware clouds:x:5036: nova:x:5037:openstack mysql:x:227: hadoop:x:5038:
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。
[root@localhost etc]# vim passwd jow:x:4067:4067::/home/jow:/bin/bash centos:x:4068:4068::/home/centos:/bin/bash user1:x:4069:4069::/home/user1:/bin/bash user2:x:4070:4070::/home/user2:/bin/bash apache:x:48:48:Apache:/usr/share/httpd:/sbin/nologin pcp:x:228:228:Performance Co-Pilot:/var/lib/pcp:/sbin/nologin named:x:25:25:Named:/var/named:/sbin/nologin magia:x:1100:1100::/home/linux:/bin/bash slackware:x:2002:2016::/home/slackware:/bin/tcsh openstack:x:3003:5036::/home/openstack:/bin/bash mysql:x:227:227::/home/mysql:/sbin/nologin hadoop:x:3004:5038::/home/hadoop:/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。
[root@localhost ~]# cp -r /etc/skel /home/hadoop [root@localhost ~]# ls -l /home | grep hadoop drwxr-xr-x. 3 root root 74 Dec 22 04:31 hadoop [root@localhost ~]# chmod -R go= /home/hadoop [root@localhost ~]# ls -al /home/hadoop total 16 drwx------. 3 root root 74 Dec 22 04:31 . drwxr-xr-x. 26 root root 4096 Dec 22 04:31 .. -rw-------. 1 root root 18 Dec 22 04:31 .bash_logout -rw-------. 1 root root 193 Dec 22 04:31 .bash_profile -rw-------. 1 root root 231 Dec 22 04:31 .bashrc drwx------. 4 root root 37 Dec 22 04:31 .mozilla [root@localhost ~]# ls -al /home | grep hadoop drwx------. 3 root root 74 Dec 22 04:31 hadoop [root@localhost ~]#
5、修改/home/hadoop目錄及其內部所有文件的屬主為hadoop，屬組為hadoop。
[root@localhost ~]# chown -R hadoop:hadoop /home/hadoop [root@localhost ~]# ls -al /home | grep hadoop drwx------. 3 hadoop hadoop 74 Dec 22 04:31 hadoop [root@localhost ~]#
6、顯示/proc/meminfo文件中以大寫或小寫S開頭的行；用兩種方式；
第一種： [root@localhost ~]# cat /proc/meminfo | grep "^[sS].*" SwapCached: 0 kB SwapTotal: 2098172 kB SwapFree: 2098172 kB Shmem: 7264 kB Slab: 114028 kB SReclaimable: 65800 kB SUnreclaim: 48228 kB 第二種： [root@localhost ~]# cat /proc/meminfo | grep -i "^s.*" SwapCached: 0 kB SwapTotal: 2098172 kB SwapFree: 2098172 kB Shmem: 7264 kB Slab: 114028 kB SReclaimable: 65800 kB SUnreclaim: 48228 kB
7、顯示/etc/passwd文件中其默認shell為非/sbin/nologin的用戶；
[root@localhost ~]# cat /etc/passwd | cut -d: -f1,7 root:/bin/bash bin:/sbin/nologin daemon:/sbin/nologin adm:/sbin/nologin lp:/sbin/nologin sync:/bin/sync shutdown:/sbin/shutdown halt:/sbin/halt mail:/sbin/nologin [root@localhost ~]# cat /etc/passwd | cut -d: -f1,7 | grep -v "/sbin/nologin" root:/bin/bash sync:/bin/sync shutdown:/sbin/shutdown halt:/sbin/halt
8、顯示/etc/passwd文件中其默認shell為/bin/bash的用戶；
[root@localhost ~]# cat /etc/passwd | cut -d: -f1,7 | grep "/bin/bash" root:/bin/bash admin:/bin/bash gentoo:/bin/bash cx:/bin/bash gestuser:/bin/bash moose:/bin/bash moosefs:/bin/bash
9、找出/etc/passwd文件中的一位數或兩位數；
[root@localhost ~]# grep "\b[0-9]\{1,2\}\b" /etc/passwd
root:x:0:0:root:/root:/bin/bash
bin:x:1:1:bin:/bin:/sbin/nologin
daemon:x:2:2:daemon:/sbin:/sbin/nologin
adm:x:3:4:adm:/var/adm:/sbin/nologin
lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
10、顯示/boot/grub/grub.conf中以至少一個空白字符開頭的行；
[root@localhost ~]# grep "^[[:space:]]*$" /boot/grub/grub.conf
11、顯示/etc/rc.d/rc.local文件中以#開頭，后面跟至少一個空白字符，而后 又有至少一個非空白字符的行；
[root@localhost rc.d]# grep "^#[[:space:]]\+[^[:space:]]\+" /etc/rc.d/rc.local # THIS FILE IS ADDED FOR COMPATIBILITY PURPOSES # It is highly advisable to create own systemd services or udev rules # to run scripts during boot instead of using this file. # In contrast to previous versions due to parallel execution during boot # this script will NOT be run after all other services. # Please note that you must run 'chmod +x /etc/rc.d/rc.local' to ensure # that this script will be executed during boot. [root@localhost rc.d]#
12、打出netstat -tan命令執行結果中以‘LISTEN’，后或跟空白字符結尾的行；
[root@localhost ~]# netstat -tan | grep "LISTEN[[:space:]]*$" 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；
[root@localhost ~]# useradd bash [root@localhost ~]# useradd testbash [root@localhost ~]# useradd basher [root@localhost ~]# useradd nologin [root@localhost ~]# tail -10 /etc/passwd named:x:25:25:Named:/var/named:/sbin/nologin magia:x:1100:1100::/home/linux:/bin/bash slackware:x:2002:2016::/home/slackware:/bin/tcsh openstack:x:3003:5036::/home/openstack:/bin/bash mysql:x:227:227::/home/mysql:/sbin/nologin hadoop:x:3004:5038::/home/hadoop:/bin/bash bash:x:4071:4071::/home/bash:/bin/bash testbash:x:4072:4072::/home/testbash:/bin/bash basher:x:4073:4073::/home/basher:/bin/bash nologin:x:4074:4074::/home/nologin:/bin/bash [root@localhost ~]# man usermod [root@localhost ~]# usermod -s /sbin/nologin nologin [root@localhost ~]# grep -E "^([^:]+\b).*\1$" /etc/passwd sync:x:5:0:sync:/sbin:/bin/sync shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown halt:x:7:0:halt:/sbin:/sbin/halt bash:x:4071:4071::/home/bash:/bin/bash nologin:x:4074:4074::/home/nologin:/sbin/nologin [root@localhost ~]#
原創文章，作者：diglinux，如若轉載，請注明出處：http://www.www58058.com/64498
不錯，完成的很好，可以看出對基礎知識這塊掌握的委扎實。再接再勵