馬哥教育網絡20期+第四周練習博客

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 ~]# cd /home/

[root@localhost home]# mkdir tuser1

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

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

 

2、  編輯/etc/group文件，添加組hadoop。

[root@localhost ~]# echo "hadoop:x:206:" >> /etc/group

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

hadoop:x:206:

 

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 ~]# echo "hadoop::206:200::/home/hadoop:/bin/basename" >> /etc/passwd

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

hadoop::206:200::/home/hadoop:/bin/basename

[root@localhost ~]#      

 

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 go-rwx  /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/

 

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:       2064380 kB

SwapFree:        2064380 kB

Shmem:              4052 kB

Slab:              66780 kB

SReclaimable:      30152 kB

SUnreclaim:        36628 kB

 

[root@localhost ~]# cat /proc/meminfo | grep ^[Ss].*

SwapCached:            0 kB

SwapTotal:       2064380 kB

SwapFree:        2064380 kB

Shmem:              4052 kB

Slab:              66784 kB

SReclaimable:      30052 kB

SUnreclaim:        36732 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

ddw

ee

user

dd

lvs

linuxso

python

ddddd

mandriva

slackware

openstack

hadoop

[root@localhost ~]#

 

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

ddw

ee

user

dd

lvs

linuxso

python

ddddd

mandriva

openstack

[root@localhost ~]#

 

9、  找出/etc/passwd文件中的一位數或兩位數；

[root@localhost ~]# cat /etc/passwd | grep -o '\<[0-9]\>\|\<[0-9][0-9]\>'

0

0

1

1

2

2

3

4

4

7

5

0

6

0

7

0

8

12

10

14

11

0

12

13

30

14

50

99

99

81

81

69

69

68

68

38

38

48

48

76

89

89

42

42

74

74

72

72

[root@localhost ~]#

 

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

[root@localhost ~]# cat /boot/grub/grub.conf | grep "^[[:space:]]\+.*"

         root (hd0,0)

         kernel /vmlinuz-2.6.32-504.el6.i686 ro root=UUID=e6891007-5edb-4ec9-b9af-2e0a319bcde5 rd_NO_LUKS rd_NO_LVM.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet

         initrd /initramfs-2.6.32-504.el6.i686.img

[root@localhost ~]#

 

 

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

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

# Taken in part from Miquel van Smoorenburg's bcheckrc.

# Check SELinux status

# Print a text banner.

# Only read this once.

# Initialize hardware

# Set default affinity

# Load other user-defined modules

# Load modules (for backward compatibility with VARs)

# Configure kernel parameters

# Set the hostname.

# Sync waiting for storage.

# Device mapper & related initialization

# Start any MD RAID arrays that haven't been started yet

# Remount the root filesystem read-write.

# Clean up SELinux labels

# If relabeling, relabel mount points.

# Mount all other filesystems (except for NFS and /proc, which is already

# mounted). Contrary to standard usage,

# filesystems are NOT unmounted in single user mode.

# The 'no' applies to all listed filesystem types. See mount(8).

# Update quotas if necessary

# Check to see if a full relabel is needed

# Initialize pseudo-random number generator

# Configure machine if necessary.

# Clean out /.

# Do we need (w|u)tmpx files? We don't set them up, but the sysadmin might…

# Clean up /var.

# Clean up utmp/wtmp

# Clean up various /tmp bits

# Make ICE directory

# Start up swapping.

# Set up binfmt_misc

# Boot time profiles. Yes, this should be somewhere else.

# Now that we have all of our basic modules loaded and the kernel going,

# let's dump the syslog ring somewhere so we can find it later

# create the crash indicator flag to warn on crashes, offer fsck with timeout

# Let rhgb know that we're leaving rc.sysinit

[root@localhost ~]#

 

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 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     

tcp        0      0 :::22                       :::*                        LISTEN     

tcp        0      0 ::1:631                     :::*                        LISTEN     

tcp        0      0 ::1:25                      :::*                        LISTEN     

[root@localhost ~]#

 

 

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 ~]# cat /etc/passwd | grep "^\(\<[[:alpha:]]\+\>\).*\1$"

\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:2004:2004::/home/bash:/bin/bash

nologin:x:2007:2007::/home/nologin:/sbin/nologin

[root@localhost ~]#