第四周 文件操作

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 -a /etc/skel /home/tuser1

[root@localhost ~]# chmod -R go= /home/tuser1

[root@localhost ~]# ls -ld /home/tuser1/

drwx——. 2 root root 4096 Nov 30 17:47 /home/tuser1/

 

[root@localhost ~]# cp -r /etc/skel /home/tuser1

[root@localhost ~]# chmod -R 700 /home/tuser1/

[root@localhost ~]# ls -ld /home/tuser1/

drwx——. 3 root root 4096 Dec 24 19:19 /home/tuser1/

2、編輯/etc/group文件，添加組hadoop

[root@localhost ~]# vi /etc/group

[root@localhost ~]# tail -1 /etc/group

hadoop:x:557

 

[root@localhost ~]# echo “hadoop:x:557” >> /etc/group && tail -1 /etc/group

hadoop:x:557

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 ~]# vi /etc/passwd

[root@localhost ~]# tail -1 /etc/passwd

hadoop:x:1009:1009::/home/hadoop:/bin/bash

 

[root@localhost ~]# echo “hadoop:x:1009:1009::/home/hadoop:/bin/bash” >> /etc/passwd && tail -1 /etc/passwd

hadoop:x:1009:1009::/home/hadoop:/bin/bash

[root@localhost ~]# id hadoop

uid=1009(hadoop) gid=1009 groups=1009

 

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 ~]# chmod -R 700 /home/hadoop

[root@localhost ~]# ls -ld /home/hadoop

drwx—— 2 root root 4096 Dec 24 19:39 /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

[root@localhost ~]# chown -R hadoop:hadoop /home/hadoop

[root@localhost ~]# ls -al /home/hadoop

total 20

drwx——?? 2 hadoop hadoop 4096 Dec 24 19:39 .

drwxr-xr-x. 12 root?? root?? 4096 Dec 24 19:39 ..

-rwx——?? 1 hadoop hadoop?? 18 Dec 24 19:39 .bash_logout

-rwx——?? 1 hadoop hadoop? 193 Dec 24 19:39 .bash_profile

-rwx——?? 1 hadoop hadoop? 231 Dec 24 19:39 .bashrc

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 ~]# grep “^[sS]” /proc/meminfo

SwapCached:??????????? 0 kB

SwapTotal:?????? 8388604 kB

SwapFree:??????? 8388604 kB

Shmem:????????????? 6896 kB

Slab:????????????? 43572 kB

SReclaimable:????? 20876 kB

SUnreclaim:??????? 22696 kB

 

[root@localhost ~]# grep -i “^s” /proc/meminfo

SwapCached:??????????? 0 kB

SwapTotal:?????? 8388604 kB

SwapFree:??????? 8388604 kB

Shmem:????????????? 6896 kB

Slab:????????????? 43572 kB

SReclaimable:????? 20876 kB

SUnreclaim:??????? 22696 kB

 

[root@localhost ~]# grep -E “^(s|S)” /proc/meminfo

SwapCached:??????????? 0 kB

SwapTotal:?????? 8388604 kB

SwapFree:??????? 8388604 kB

Shmem:????????????? 6896 kB

Slab:????????????? 43572 kB

SReclaimable:????? 20876 kB

SUnreclaim:??????? 22696 kB

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

[root@localhost ~]# grep -v “/sbin/nologin$” /etc/passwd |cut -d: -f1

root

sync

shutdown

halt

gentpp

gentoo

fedora

mageia

slackware

gentnn

slack

centos

hadoop

[root@localhost ~]# grep -v “nologin\>$” /etc/passwd |cut -d: -f1

root

sync

shutdown

halt

gentpp

gentoo

fedora

mageia

slackware

gentnn

slack

centos

hadoop

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

[root@localhost ~]# grep “/bin/bash$” /etc/passwd | cut -d: -f1

root

gentoo

mageia

gentnn

centos

hadoop

 

[root@localhost ~]# grep “bash\>$” /etc/passwd | cut -d: -f1

root

gentoo

mageia

gentnn

centos

hadoop

9、找出/etc/passwd文件中的一位數或兩位數

[root@localhost ~]# grep “\<[0-9]\{1,2\}\>” /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

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

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

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

mail:x:8:12:mail:/var/spool/mail:/sbin/nologin

operator:x:11:0:operator:/root:/sbin/nologin

games:x:12:100:games:/usr/games:/sbin/nologin

ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin

nobody:x:99:99:Nobody:/:/sbin/nologin

dbus:x:81:81:System message bus:/:/sbin/nologin

postfix:x:89:89::/var/spool/postfix:/sbin/nologin

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

rpc:x:32:32:Rpcbind Daemon:/var/lib/rpcbind:/sbin/nologin

rpcuser:x:29:29:RPC Service User:/var/lib/nfs:/sbin/nologin

[root@localhost ~]# grep “\<[0-9]\{1,2\}\>” /etc/passwd | cut -d: -f3 | sort -n

0

1

2

3

4

5

6

7

8

11

12

14

29

32

74

81

89

99

 

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

[root@localhost ~]# ls -ld /boot/grub

drwxr-xr-x. 2 root root 4096 Nov 30 17:49 /boot/grub

[root@localhost ~]# ls /boot/grub

splash.xpm.gz

[root@localhost ~]# ls /boot/grub2

device.map? fonts? grub.cfg? grubenv? i386-pc? locale

 

[root@localhost ~]# grep “^[[:space:]]\+.*” /boot/grub2/grub.cfg | wc -l

64

 

[root@localhost ~]# grep “^[[:space:]]\+.*” /boot/grub/grub.conf

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 ~]# grep “^#[[:space:]]\+[^[:space:]]\+” /etc/rc.d/rc.sysinit

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

Active Internet connections (servers and established)

Proto Recv-Q Send-Q Local Address?????????? Foreign Address???????? State

tcp??????? 0????? 0 0.0.0.0:111???????????? 0.0.0.0:*?????????????? LISTEN

tcp??????? 0????? 0 0.0.0.0:22????????????? 0.0.0.0:*?????????????? LISTEN

tcp??????? 0????? 0 127.0.0.1:25??????????? 0.0.0.0:*?????????????? LISTEN

tcp??????? 0????? 0 192.168.43.191:22?????? 192.168.43.233:50240??? ESTABLISHED

tcp??????? 0???? 52 192.168.43.191:22?????? 192.168.43.233:51118??? ESTABLISHED

tcp6?????? 0????? 0 :::111????????????????? :::*??????????????????? LISTEN

tcp6?????? 0????? 0 :::22?????????????????? :::*??????????????????? LISTEN

tcp6?????? 0????? 0 ::1:25????????????????? :::*??????????????????? LISTEN

[root@localhost ~]# netstat -tan | grep “LISTEN[[:space:]]*$”

tcp??????? 0????? 0 0.0.0.0:111???????????? 0.0.0.0:*????????????? ? LISTEN

tcp??????? 0????? 0 0.0.0.0:22????????????? 0.0.0.0:*????????????? ? LISTEN

tcp??????? 0????? 0 127.0.0.1:25??????????? 0.0.0.0:*?????????????? LISTEN

tcp6?????? 0????? 0 :::111????????????????? :::*?????????????????????????????? LISTEN?

tcp6?????? 0????? 0 :::22?????????????????? :::*?????????????????? ? ? ? ? ? ? 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 -s /sbin/nologin nologin

[root@localhost ~]# tail -4 /etc/passwd

bash:x:4006:4006::/home/bash:/bin/bash

testbash:x:4007:4007::/home/testbash:/bin/bash

basher:x:4008:4008::/home/basher:/bin/bash

nologin:x:4009:4009::/home/nologin:/sbin/nologin

 

[root@localhost ~]# grep? -E? “^([^:]+\>).*\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:4006:4006::/home/bash:/bin/bash

nologin:x:4009:4009::/home/nologin:/sbin/nologin