第四周作业

1. 复制/etc/skel目录为/home/tuser1，要求/home/tuser1及其内部文件的属组和其它用户均没有任何访问权限

[root@localhost ~]# chmod -R g=,o=  /home/tuser1

[root@localhost home]# ll

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

2. 编辑/etc/group文件，添加组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. 手动编辑/etc/passwd文件新增一行，添加用户hadoop，其基本组ID为hadoop组的id号；其家目录为/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. 复制/etc/skel目录为/home/hadoop，要求修改hadoop目录的属组和其它用户没有任何访问权限

[root@localhost ~]# chmod  g=,o= /home/Hadoop 八进制赋权

[root@localhost hadoop]# chmod  g-wrx,o-rwx /home/Hadoop 控制权限位赋权

5. 修改/home/hadoop目录及其内部所有文件的属主为hadoop，属组为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. 显示/proc/meminfo文件中以大写或小写S开头的行；用两种方式

[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. 显示/etc/passwd文件中其默认shell为非/sbin/nologin的用户

[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. 显示/etc/passwd文件中其默认shell为/bin/bash的用户

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

9. 找出/etc/passwd文件中的一位数或两位数

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

10. 显示/boot/grub/grub.conf中以至少一个空白字符开头的行

[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. 显示/etc/rc.d/rc.sysinit文件中以#开头，后面跟至少一个空白字符，而后又有至少一个非空白字符的行

[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命令执行结果中以‘LISTEN’，后或跟空白字符结尾的行

[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. 添加用户bash, testbash, basher, nologin (此一个用户的shell为/sbin/nologin)，而后找出当前系统上其用户名和默认shell相同的用户的信息；

[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. 显示/proc/meminfo文件中以大写或小写S开头的行；用三种方式

[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