马哥linux课后作业4

Posted 2020-08-04

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。

[[email protected] home]# cp -r /etc/skel/ /home/tuser1

[[email protected] home]# chmod -R u-r,o-r tuser1/

[[email protected] home]# ll

total 40

drwx------. 2 bash      bash     4096 Aug 13 12:01 bash

drwx------. 2 basher    basher   4096 Aug 13 12:01 basher

drwx------. 2 mageia    mageia   4096 Aug 14 01:14 linux

drwx------. 2      1005 distro   4096 Aug 14 01:12 mandriva

drwx------. 2 nologin   nologin  4096 Aug 13 12:01 nologin

drwx------. 2 openstack clouds   4096 Aug 14 01:50 openstack

drwx------. 2 slackware distro   4096 Aug 14 01:24 slackware

drwx------. 2 testbash  testbash 4096 Aug 13 12:01 testbash

d-wxr-x--x. 2 root      root     4096 Aug 14 13:58 tuser1

drwx------. 2 zengzy    zengzy   4096 Aug 13 08:28 zengzy

[[email protected] home]# su zengzy

[[email protected] home]$ cd /home/tuser1/

[[email protected] tuser1]$ ls

ls: cannot open directory .: Permission denied

2、编辑/etc/group文件，添加组hadoop。

[[email protected] home]# vim /etc/group

[email protected] home]# tail -n 5 /etc/group

admins:x:2018:slackware

clouds:x:2019:

nova:x:2020:openstack

mysql:x:498:

hadoop:x:499:

[[email protected] home]# echo ‘hadoop1:x:505:‘ >> /etc/group

[[email protected] home]# tail -n 1 /etc/group

hadoop1:x:505:

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。

[[email protected] home]# vim /etc/passwd

hadoop:x:505:499::/home/hadoop:/bin/bash

[[email protected] home]# id hadoop

uid=505(hadoop) gid=499(hadoop) groups=499(hadoop)

[[email protected] home]# echo ‘hadoop1:x:506:505::/home/hadpood1:/bin/bash‘ >> /etc/passwd

[[email protected] home]# id hadoop1

uid=506(hadoop1) gid=505(hadoop1) groups=505(hadoop1)

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。

[[email protected] home]# cp -r /etc/skel /home/hadoop

[[email protected] home]# ll

total 44

drwx------. 2 bash      bash     4096 Aug 13 12:01 bash

drwx------. 2 basher    basher   4096 Aug 13 12:01 basher

drwxr-xr-x. 2 root      root     4096 Aug 14 14:22 hadoop

drwx------. 2 mageia    mageia   4096 Aug 14 01:14 linux

drwx------. 2      1005 distro   4096 Aug 14 01:12 mandriva

drwx------. 2 nologin   nologin  4096 Aug 13 12:01 nologin

drwx------. 2 openstack clouds   4096 Aug 14 01:50 openstack

drwx------. 2 slackware distro   4096 Aug 14 01:24 slackware

drwx------. 2 testbash  testbash 4096 Aug 13 12:01 testbash

d-wxr-x--x. 2 root      root     4096 Aug 14 13:58 tuser1

drwx------. 2 zengzy    zengzy   4096 Aug 13 08:28 zengzy

[[email protected] home]# chmod g-r,o-r hadoop/

[[email protected] home]# ll

total 44

drwx------. 2 bash      bash     4096 Aug 13 12:01 bash

drwx------. 2 basher    basher   4096 Aug 13 12:01 basher

drwx--x--x. 2 root      root     4096 Aug 14 14:22 hadoop

drwx------. 2 mageia    mageia   4096 Aug 14 01:14 linux

drwx------. 2      1005 distro   4096 Aug 14 01:12 mandriva

drwx------. 2 nologin   nologin  4096 Aug 13 12:01 nologin

drwx------. 2 openstack clouds   4096 Aug 14 01:50 openstack

drwx------. 2 slackware distro   4096 Aug 14 01:24 slackware

drwx------. 2 testbash  testbash 4096 Aug 13 12:01 testbash

d-wxr-x--x. 2 root      root     4096 Aug 14 13:58 tuser1

drwx------. 2 zengzy    zengzy   4096 Aug 13 08:28 zengzy

5、修改/home/hadoop目录及其内部所有文件的属主为hadoop，属组为hadoop。

[[email protected] home]# ll

total 44

drwx------. 2 bash      bash     4096 Aug 13 12:01 bash

drwx------. 2 basher    basher   4096 Aug 13 12:01 basher

drwx--x--x. 2 root      root     4096 Aug 14 14:22 hadoop

drwx------. 2 mageia    mageia   4096 Aug 14 01:14 linux

drwx------. 2      1005 distro   4096 Aug 14 01:12 mandriva

drwx------. 2 nologin   nologin  4096 Aug 13 12:01 nologin

drwx------. 2 openstack clouds   4096 Aug 14 01:50 openstack

drwx------. 2 slackware distro   4096 Aug 14 01:24 slackware

drwx------. 2 testbash  testbash 4096 Aug 13 12:01 testbash

d-wxr-x--x. 2 root      root     4096 Aug 14 13:58 tuser1

drwx------. 2 zengzy    zengzy   4096 Aug 13 08:28 zengzy

[[email protected] home]# chown -R hadoop:hadoop hadoop/

[[email protected] home]# ll

total 44

drwx------. 2 bash      bash     4096 Aug 13 12:01 bash

drwx------. 2 basher    basher   4096 Aug 13 12:01 basher

drwx--x--x. 2 hadoop    hadoop   4096 Aug 14 14:22 hadoop

drwx------. 2 mageia    mageia   4096 Aug 14 01:14 linux

drwx------. 2      1005 distro   4096 Aug 14 01:12 mandriva

drwx------. 2 nologin   nologin  4096 Aug 13 12:01 nologin

drwx------. 2 openstack clouds   4096 Aug 14 01:50 openstack

drwx------. 2 slackware distro   4096 Aug 14 01:24 slackware

drwx------. 2 testbash  testbash 4096 Aug 13 12:01 testbash

d-wxr-x--x. 2 root      root     4096 Aug 14 13:58 tuser1

drwx------. 2 zengzy    zengzy   4096 Aug 13 08:28 zengzy

6、显示/proc/meminfo文件中以大写或小写S开头的行；用两种方式；

[[email protected] home]# cat /proc/meminfo | grep "^[sS]"

SwapCached:            0 kB

SwapTotal:       2097148 kB

SwapFree:        2097148 kB

Shmem:               236 kB

Slab:             106148 kB

SReclaimable:      46064 kB

SUnreclaim:        60084 kB

[[email protected] home]# cat /proc/meminfo | grep -i "^s"

SwapCached:            0 kB

SwapTotal:       2097148 kB

SwapFree:        2097148 kB

Shmem:               236 kB

Slab:             106144 kB

SReclaimable:      46060 kB

SUnreclaim:        60084 kB

7、显示/etc/passw d文件中其默认shell为非/sbin/nologin的用户；

[[email protected] home]# cat /etc/passwd | grep  -v "/sbin/nologin$" | cut -d: -f1

root

sync

shutdown

halt

zengzy

bash

basher

testbash

mageia

slackware

openstack

hadoop

hadoop1

8、显示/etc/passw d文件中其默认shell为/bin/bash的用户；

[[email protected] home]# cat /etc/passwd | grep "/bin/bash$" | cut -d: -f1

root

zengzy

bash

basher

testbash

mageia

openstack

hadoop

hadoop1

9、找出/etc/passw d文件中的一位数或两位数；

[[email protected] home]# egrep "\<[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

uucp:x:10:14:uucp:/var/spool/uucp:/sbin/nologin

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

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

gopher:x:13:30:gopher:/var/gopher:/sbin/nologin

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

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

vcsa:x:69:69:virtual console memory owner:/dev:/sbin/nologin

saslauth:x:499:76:Saslauthd user:/var/empty/saslauth:/sbin/nologin

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

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

[[email protected] home]# grep  --color=auto "\<[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

uucp:x:10:14:uucp:/var/spool/uucp:/sbin/nologin

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

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

gopher:x:13:30:gopher:/var/gopher:/sbin/nologin

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

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

vcsa:x:69:69:virtual console memory owner:/dev:/sbin/nologin

saslauth:x:499:76:Saslauthd user:/var/empty/saslauth:/sbin/nologin

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

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

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

[[email protected] home]# grep "^[[:space:]]\+" /boot/grub/grub.conf 

   root (hd0,0)

   kernel /vmlinuz-2.6.32-642.4.2.el6.x86_64 ro root=UUID=b175aee5-62ee-4625-8aac-f3c455133efa rd_NO_LUKS rd_NO_LVM LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet

initrd /initramfs-2.6.32-642.4.2.el6.x86_64.img

   root (hd0,0)

   kernel /vmlinuz-2.6.32-642.el6.x86_64 ro root=UUID=b175aee5-62ee-4625-8aac-f3c455133efa rd_NO_LUKS rd_NO_LVM LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet

   initrd /initramfs-2.6.32-642.el6.x86_64.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；

[[email protected] home]# grep "^#[[:space:]]\+[^[:space:]]\+" /etc/rc.d/rc.sysinit 

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；

[[email protected] home]# netstat -tan | egrep "LISTTEN|[[:space:]]$"

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

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     64 192.168.2.105:22            192.168.2.106:12341         ESTABLISHED 

tcp        0      0 192.168.2.105:22            192.168.2.106:3099          ESTABLISHED 

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

tcp        0      0 ::1:25                      :::*                        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；

[[email protected] home]# useradd bash

[[email protected] home]# useradd tetstbash

[[email protected] home]# useradd basher

[[email protected] home]# useradd -s /sbin/nologin nologin

[[email protected] home]# grep --color=auto "^\([[:alnum:]]\+\>\).*\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:501:501::/home/bash:/bin/bash

nologin:x:504:504::/home/nologin:/sbin/nologin

本文出自 “给自己充电” 博客，请务必保留此出处http://zengzeyang.blog.51cto.com/6129531/1842811