第四周作業

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 ~]# chmod -R g=,o=  /home/tuser1

[root@localhost home]# ll

drwx——  3 root      root     4096 Dec 26 10:43 tuser1

2. 編輯/etc/group文件，添加組hadoop

[root@localhost home]# vim /etc/group

testgrp4:x:5005:

hadoop:x:5006: <-使用g插入hadoop信息，末行模式下：x保存

distro:x:2016:

mageia:x:1100:

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 home]# vim /etc/passwd

testgrp4:x:5003:5005::/home/testgrp4:/bin/bash

hadoop:x:5004:5006::/home/hadoop:/bin/bash <-使用g插入hadoop信息，末行模式下：x保存

mageia:x:1100:1100::/home/linux:/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 ~]# chmod  g=,o= /home/Hadoop 八進制賦權

[root@localhost hadoop]# chmod  g-wrx,o-rwx /home/Hadoop 控制權限位賦權

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 home]# chown -R hadoop:hadoop /home/hadoop/

[root@localhost home]# ll /home/hadoop/

total 4

drwxr-xr-x 3 hadoop hadoop 4096 Dec 26 10:59 skel

6. 顯示/proc/meminfo文件中以大寫或小寫S開頭的行；用兩種方式

[root@localhost home]# grep "^[sS]" /proc/meminfo

[root@localhost home]# grep  -i "^s" /proc/meminfo

SwapCached:          0 kB

SwapTotal:     2097144 kB

SwapFree:      2097144 kB

Slab:            16564 kB

7. 顯示/etc/passwd文件中其默認shell為非/sbin/nologin的用戶

[root@localhost home]# grep -v "/sbin/nologin" /etc/passwd

root:x:0:0:root:/root:/bin/bash

sync:x:5:0:sync:/sbin:/bin/sync

shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown

halt:x:7:0:halt:/sbin:/sbin/halt

news:x:9:13:news:/etc/news:

oracle:x:500:500::/home/oracle:/bin/bash

hive:x:5000:5000:hive:/home/hive:/bin/bash

docker:x:5001:5001::/home/docker:/bin/bash

testgrp3:x:5002:5001:hello:/home/testgrp3:/bin/bash

testgrp4:x:5003:5005::/home/testgrp4:/bin/bash

hadoop:x:5004:5006::/home/hadoop:/bin/bash

mageia:x:1100:1100::/home/linux:/bin/bash

slackware:x:2002:2016::/home/slackware:/bin/tcsh

openstack:x:3003:5010::/home/openstack:/bin/bash

8. 顯示/etc/passwd文件中其默認shell為/bin/bash的用戶

[root@localhost home]# grep "/bin/bash" /etc/passwd9.

9. 找出/etc/passwd文件中的一位數或兩位數

[root@localhost home]# grep -o "\<[0-9]\{1,2\}\>" /etc/passwd | sort –n

10. 顯示/boot/grub/grub.conf中以至少一個空白字符開頭的行

[root@localhost home]# grep "^[[:space:]]\+" /boot/grub/grub.conf

        root (hd0,0)

        kernel /vmlinuz-2.6.18-164.el5 ro root=/dev/VolGroup00/LogVol00 rhgb quiet

        initrd /initrd-2.6.18-164.el5.img

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

[root@localhost home]# grep "^#\+[[:space:]]\+[^[:space:]]" /etc/rc.d/rc.sysinit

# /etc/rc.d/rc.sysinit – run once at boot time

#       /etc/init.d/diskdump swapsavecore

# Start up swapping.

…

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 home]# netstat -tan | grep "LISTEN[[:space:]]*$"

tcp        0      0 127.0.0.1:2208              0.0.0.0:*                   LISTEN     

tcp        0      0 0.0.0.0:111                 0.0.0.0:*                   LISTEN     

tcp        0      0 0.0.0.0:690                 0.0.0.0:*                   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 home]# grep – E "^([^:]+\>).*\1$" /etc/passwd

/etc/passwd:sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin

/etc/passwd:avahi-autoipd:x:100:101:avahi-autoipd:/var/lib/avahi-autoipd:/sbin/nologin

14. 顯示/proc/meminfo文件中以大寫或小寫S開頭的行；用三種方式

[root@localhost rc.d]# grep -i "^s" /proc/meminfo

[root@localhost rc.d]# grep "^[sS]" /proc/meminfo

[root@localhost rc.d]# grep -E "^(s|S)" /proc/meminfo

SwapCached: 0 kB

SwapTotal: 2097144 kB

SwapFree: 2097144 kB

Slab: 29744 kB