N22-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 ~]# cp -r /etc/skel /home/tuser1    (復制/etc/skel為/home/tuser1)

[root@localhost ~]# chmod -R 700 /home/tuser1       （修改/home/tuser1目錄及其內部所有文件的權限）

[root@localhost ~]# ll -d /home/tuser1;ll -a /home/tuser1    （查看修改后的結果）

drwx——. 2 root root 59 Aug 29 12:25 /home/tuser1

total 12

drwx——. 2 root root  59 Aug 29 12:25 .

drwxr-xr-x. 9 root root 102 Aug 29 12:25 ..        （此目錄是/home/tusr1的上一級目錄，所以權限沒有改變）

-rwx——. 1 root root  18 Aug 29 12:25 .bash_logout

-rwx——. 1 root root 193 Aug 29 12:25 .bash_profile

-rwx——. 1 root root 231 Aug 29 12:25 .bashrc

2、編輯/etc/group文件，添加組hadoop。

[root@localhost ~]# vim /etc/group    （用vim編輯/etc/group文件）

hadoop:x:4000:        （在文件的最后寫入此行，保存退出）

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 ~]# vim /etc/passwd        （用vim編輯/etc/passwd文件）

hadoop:x:3006:4000:/home/hadoop:/bin/bash    （在文件的最后寫入此行，保存退出）

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        （復制/etc/skel為/home/hadoop）

[root@localhost ~]# chmod 700 /home/hadoophome/hadoop    (修改/home/hadoop目錄權限)

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        （修改/home/hadoop目錄及其內部文件的屬主和屬主）

[root@localhost ~]# ll -d /home/hadoop;ll -a /home/hadoop        （查看修改后的結果）

drwx——. 2 hadoop hadoop 59 Aug 29 12:53 /home/hadoop

total 16

drwx——.  2 hadoop hadoop   59 Aug 29 12:53 .

drwxr-xr-x. 10 root   root   4096 Aug 29 12:53 ..

-rwx——.  1 hadoop hadoop   18 Aug 29 12:53 .bash_logout

-rwx——.  1 hadoop hadoop  193 Aug 29 12:53 .bash_profile

-rwx——.  1 hadoop hadoop  231 Aug 29 12:53 .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 -i "^s" /proc/meminfo       （grep "^[sS]" /proc/meminfo） (grep -E "^(s|S)" /proc/meminfo)

SwapCached:            0 kB

SwapTotal:       1952764 kB

SwapFree:        1952764 kB

Shmem:              6856 kB

Slab:              55008 kB

SReclaimable:      20496 kB

SUnreclaim:        34512 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

mageia

slackware

openstack

user1

user2

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

mageia

openstack

user1

user2

hadoop

9、找出/etc/passwd文件中的一位數或兩位數；

[root@localhost grub]# grep "\<[[:digit:]]\{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

tss:x:59:59:Account used by the trousers package to sandbox the tcsd daemon:/dev/null:/sbin/nologin

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

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

    root (hd0,0)

    kernel /vmlinuz-2.6.32-431.el6.x86_64 ro root=/dev/mapper/VolGroup-lv_root rd_NO_LUKS.UTF-8 rd_NO_MD rd_LVM_LV=VolGroup/lv_swap SYSFONT=latarcyrheb-sun16 crashkernel=auto rd_LVM_LV=VolGroup/lv_root  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet

    initrd /initramfs-2.6.32-431.el6.x86_64.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 ~]# 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

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 -E "LISTEN[[:space:]]*$"

tcp        0      0 0.0.0.0:48333               0.0.0.0:*                   LISTEN      

tcp        0      0 0.0.0.0:111                 0.0.0.0:*                   LISTEN      

tcp        0      0 0.0.0.0:22                  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 :::111                      :::*                        LISTEN      

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

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

tcp        0      0 :::42999                    :::*                        LISTEN      

tcp        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 ~]# 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

nologin:x:1001:1001::/home/nologin:/sbin/nologin

bash:x:1002:1002::/home/bash:/bin/bash