壹.复制/etc/skel目录为/home/tuser1,需求/home/tuser一及其内部文件的属组和别的用户均未有别的访问权限。

  1. 复制/etc/skel目录为/home/tuser壹,须要/home/tuser1及其内部文件的属组和任何用户均未有其余访问权限

复制/etc/skel目录为/home/tuser壹,需求/home/tuser一及其内部文件的属组和任何用户均未有其余访问权限。

cp -rv /etc/skel/ /home/tuser1
----------------------------------------
[root@localhost ~]# cp -rv /etc/skel/ /home/tuser1
‘/etc/skel/’ -> ‘/home/tuser1’
‘/etc/skel/.mozilla’ -> ‘/home/tuser1/.mozilla’
‘/etc/skel/.mozilla/extensions’ -> ‘/home/tuser1/.mozilla/extensions’
‘/etc/skel/.mozilla/plugins’ -> ‘/home/tuser1/.mozilla/plugins’
‘/etc/skel/.bash_logout’ -> ‘/home/tuser1/.bash_logout’
‘/etc/skel/.bash_profile’ -> ‘/home/tuser1/.bash_profile’
‘/etc/skel/.bashrc’ -> ‘/home/tuser1/.bashrc’
----------------------------------------

chmod -R go= /home/tuser1
----------------------------------------
[root@localhost ~]# chmod -R go= /home/tuser1
[root@localhost ~]# ls -ld /home/tuser1/
drwx------. 3 root root 74 Mar  2 23:39 /home/tuser1/
----------------------------------------

壹、复制/etc/skel目录为/home/tuser1,必要/home/tuser1及其内部文件的属组和任何用户均未有任何访问权限。

[root@localhost tuser1]# cp -r /etc/skel/ /home/tuser1
[root@localhost tuser1]# chmod -R go= /home/tuser1/
[root@localhost tuser1]# ll -d /home/tuser1/
drwx------. 2 root root 71 Dec 26 08:40 /home/tuser1/
[root@centos7 ~]#cp -rv /etc/skel/ /home/tuser1

‘/etc/skel/’ -> ‘/home/tuser1’

‘/etc/skel/.mozilla’ -> ‘/home/tuser1/.mozilla’

‘/etc/skel/.mozilla/extensions’ -> ‘/home/tuser1/.mozilla/extensions’

‘/etc/skel/.mozilla/plugins’ -> ‘/home/tuser1/.mozilla/plugins’

‘/etc/skel/.bash_logout’ -> ‘/home/tuser1/.bash_logout’

‘/etc/skel/.bash_profile’ -> ‘/home/tuser1/.bash_profile’

‘/etc/skel/.bashrc’ -> ‘/home/tuser1/.bashrc’

[root@centos7 ~]#chmod -R 700 /home/tuser1/

[root@centos7 ~]#ll -a /home/tuser1/

total 12

drwx------. 3 root root 78 Jul 14 17:19 .

drwxr-xr-x. 11 root root 133 Jul 14 17:19 ..

-rwx------. 1 root root 18 Jul 14 17:19 .bash_logout

-rwx------. 1 root root 193 Jul 14 17:19 .bash_profile

-rwx------. 1 root root 231 Jul 14 17:19 .bashrc

drwx------. 4 root root 39 Jul 14 17:19 .mozilla
![](https://github.com/sfz0311/Pictures/raw/master/week4_Q1.PNG)

编辑/etc/group文件,添加组hadoop。

vim  /etc/group 按o键进入编辑模式,输入:hadoop:x:2005
按esc键进入命令模式,按shift+:进入末行模式输入
:wq 回车键保存退出
----------------------------------------
[root@localhost ~]# grep hadoop /etc/group
hadoop:x:2005:
----------------------------------------

2、编辑/etc/group文件,添加组hadoop。

[root@localhost tuser1]# echo "hadoop:x:2019:" >> /etc/group

2.编辑/etc/group文件,添加组hadoop。

  1. 编辑/etc/group文件,添加组hadoop。

手动编辑/etc/passwd文件新增壹行,添加用户hadoop,其基本组ID为hadoo组的id号;其家目录为/home/hadoop。

mkdir -v /home/hadoop
----------------------------------------
[root@localhost ~]# mkdir -v /home/hadoop
mkdir: created directory ‘/home/hadoop’
----------------------------------------
vim /etc/passwd 按o键进入编辑模式输入:
hadoop:x:2005:2005:hadoop:/home/hadoop:/bin/bash
按esc键进入命令模式,按shift+:进入末行模式输入
:wq 回车键保存退出
----------------------------------------
[root@localhost ~]# grep hadoop /etc/passwd
hadoop:x:2005:2005:hadoop:/home/hadoop:/bin/bash
----------------------------------------

三、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 tuser1]# echo "hadoop:x:2003:2019::/home/hadoop:/bin/bash" >> /etc/passwd
[root@localhost tuser1]# tail -2 /etc/passwd
slackware:x:2002:2016::/home/slackware:/bin/tcsh
hadoop:x:2003:2019::/home/hadoop:/bin/bash
[root@centos7 ~]#vim /etc/group

-使用vim编辑器打开/etc/group文件,输入G跳转到最后一行,然后输入o进入编辑模式,添加:hadoop:x:5004后点击esc键后输入:wq,保存退出。

[root@centos7 ~]#tail -1 /etc/group

hadoop:x:5004
![](https://github.com/sfz0311/Pictures/raw/master/week4_Q2.PNG)

复制/etc/skel目录为/home/hadoop,供给修改hadoop目录的属组和其余用户未有其他访问权限。

cp -rv /etc/skel/ /home/hadoop 
----------------------------------------
[root@localhost ~]# cp -rv /etc/skel/ /home/hadoop 
‘/etc/skel/’ -> ‘/home/hadoop/skel’
‘/etc/skel/.mozilla’ -> ‘/home/hadoop/skel/.mozilla’
‘/etc/skel/.mozilla/extensions’ -> ‘/home/hadoop/skel/.mozilla/extensions’
‘/etc/skel/.mozilla/plugins’ -> ‘/home/hadoop/skel/.mozilla/plugins’
‘/etc/skel/.bash_logout’ -> ‘/home/hadoop/skel/.bash_logout’
‘/etc/skel/.bash_profile’ -> ‘/home/hadoop/skel/.bash_profile’
‘/etc/skel/.bashrc’ -> ‘/home/hadoop/skel/.bashrc’
----------------------------------------
chmod go= /home/hadoop
----------------------------------------
[root@localhost ~]# chmod go= /home/hadoop
[root@localhost ~]# ls -ld /home/hadoop/
drwx------. 3 root root 17 Mar  2 23:57 /home/hadoop/
----------------------------------------

四、复制/etc/skel目录为/home/hadoop,供给修改hadoop目录的属组和别的用户未有别的访问权限。

[root@localhost tuser1]# cp -r /etc/skel/ /home/hadoop
[root@localhost tuser1]# chmod -R go= /home/hadoop/
[root@localhost tuser1]# ll -d /home/hadoop/
drwx------. 2 root root 71 Dec 26 08:42 /home/hadoop/

三.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。

  1. 用户组手动添加及管理命令和正则表明式用法示例,用户管理及grep。手动编辑/etc/passwd文件新增1行,添加用户hadoop,其基本组ID为hadoop组的id号;其家目录为/home/hadoop。

修改/home/hadoop目录及其内部装有文件的属主为hadoop,属组为hadoop。

chown -Rv hadoop:hadoop /home/hadoop/
----------------------------------------
[root@localhost ~]# chown -Rv hadoop:hadoop /home/hadoop/
changed ownership of ‘/home/hadoop/skel/.mozilla/extensions’ from root:root to hadoop:hadoop
changed ownership of ‘/home/hadoop/skel/.mozilla/plugins’ from root:root to hadoop:hadoop
changed ownership of ‘/home/hadoop/skel/.mozilla’ from root:root to hadoop:hadoop
changed ownership of ‘/home/hadoop/skel/.bash_logout’ from root:root to hadoop:hadoop
changed ownership of ‘/home/hadoop/skel/.bash_profile’ from root:root to hadoop:hadoop
changed ownership of ‘/home/hadoop/skel/.bashrc’ from root:root to hadoop:hadoop
changed ownership of ‘/home/hadoop/skel’ from root:root to hadoop:hadoop
changed ownership of ‘/home/hadoop/’ from root:root to hadoop:hadoop
----------------------------------------

5、修改/home/hadoop目录及其内部有着文件的属主为hadoop,属组为hadoop。

[root@localhost tuser1]# chown -R hadoop:hadoop /home/hadoop/
[root@localhost tuser1]# ll //home/hadoop/
total 0
-rw-------. 1 hadoop hadoop 0 Dec 26 08:42 1
[root@centos7 ~]#vim /etc/passwd

-使用vim编辑器打开/etc/passwd文件,输入G跳转到最后一行,然后输入o进入编辑模式,添加hadoop:x:2003:5004::/home/hadoop:/bin/bash后点击esc键后输入:wq,保存退出:

[root@centos7 ~]#tail -1 /etc/passwd

hadoop:x:2003:5004::/home/hadoop:/bin/bash

~]# vi /etc/passwd
在最终一行添加 hadoop:x:300:300::/home/hadoop:/sbin/nologin
然后~]# tail -1 /etc/passwd

澳门金沙国际 1

体现/proc/meminfo文件中以大写或小写S开端的行;用三种艺术;

  方式1 grep -i ^s /proc/meminfo
----------------------------------------
[root@localhost ~]# grep -i ^s /proc/meminfo
SwapCached:            0 kB
SwapTotal:       4079612 kB
SwapFree:        4079612 kB
Shmem:             10036 kB
Slab:             153420 kB
SReclaimable:      90028 kB
SUnreclaim:        63392 kB
----------------------------------------
  方式2 egrep "^(s|S)" /proc/meminfo
----------------------------------------
[root@localhost ~]# egrep "^(s|S)" /proc/meminfo
SwapCached:            0 kB
SwapTotal:       4079612 kB
SwapFree:        4079612 kB
Shmem:             10036 kB
Slab:             153436 kB
SReclaimable:      90028 kB
SUnreclaim:        63408 kB
----------------------------------------

六、展现/proc/meminfo文件中以大写或小写S初始的行;用二种艺术。

[root@localhost tuser1]# cat /proc/meminfo |grep "^[sS]" 
SwapCached:            0 kB
SwapTotal:       9764860 kB
SwapFree:        9764860 kB
Shmem:              6860 kB
Slab:              62908 kB
SReclaimable:      23144 kB
SUnreclaim:        39764 kB

[root@localhost tuser1]# cat /proc/meminfo |grep -i "^s" 
SwapCached:            0 kB
SwapTotal:       9764860 kB
SwapFree:        9764860 kB
Shmem:              6860 kB
Slab:              62916 kB
SReclaimable:      23144 kB
SUnreclaim:        39772 kB

4.复制/etc/skel目录为/home/hadoop,须要修改hadoop目录的属组和其余用户并未其余访问权限。

  1. 复制/etc/skel目录为/home/hadoop,须要修改hadoop目录的属组和任何用户并没有任何访问权限。

呈现/etc/passwd文件中其默许shell为非/sbin/nologin的用户;

cat /etc/passwd | grep -v "/sbin/nologin" | cut -d: -f1
----------------------------------------
[root@localhost ~]# cat /etc/passwd | grep -v "/sbin/nologin" | cut -d: -f1
root
sync
shutdown
halt
linuxprobe
hadoop
----------------------------------------

7、突显/etc/passwd文件中其暗中认可shell为非/sbin/nologin的用户。

[root@localhost /]# cat /etc/passwd|grep -v "/bin/bash$"|cut -d: -f1|wc -l
21
[root@centos7 ~]#cp -rv /etc/skel/ /home/hadoop

‘/etc/skel/’ -> ‘/home/hadoop’

‘/etc/skel/.mozilla’ -> ‘/home/hadoop/.mozilla’

‘/etc/skel/.mozilla/extensions’ -> ‘/home/hadoop/.mozilla/extensions’

‘/etc/skel/.mozilla/plugins’ -> ‘/home/hadoop/.mozilla/plugins’

‘/etc/skel/.bash_logout’ -> ‘/home/hadoop/.bash_logout’

‘/etc/skel/.bash_profile’ -> ‘/home/hadoop/.bash_profile’

‘/etc/skel/.bashrc’ -> ‘/home/hadoop/.bashrc’

[root@centos7 ~]#chmod 700 /home/hadoop/
![](https://github.com/sfz0311/Pictures/raw/master/week4_Q4.PNG)

显示/etc/passwd文件中其默许shell为/bin/bash的用户;

cat /etc/passwd | grep "/bin/bash" | cut -d: -f1
----------------------------------------
[root@localhost ~]# cat /etc/passwd | grep "/bin/bash" | cut -d: -f1
root
linuxprobe
hadoop
----------------------------------------

八、突显/etc/passwd文件中其暗中同意shell为/bin/bash的用户。

[root@localhost /]# cat  /etc/passwd|grep "/bin/bash$" |cut -d: -f1
root
centos
mageia
hadoop
bash
testbash
basher

伍.修改/home/hadoop目录及其内部有着文件的属主为hadoop,属组为hadoop。

  1. 修改/home/hadoop目录及其内部有着文件的属主为hadoop,属组为hadoop。

澳门金沙国际,找出/etc/passwd文件中的1位数或两位数;

  方法一:grep "\<[0-9]\{1,2\}\>" /etc/passwd
----------------------------------------
[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
----------------------------------------
  方法二:grep "\<[0-9][0-9]\?\>" /etc/passwd
----------------------------------------
[root@localhost ~]# grep "\<[0-9][0-9]\?\>" /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
----------------------------------------

玖、找出/etc/passwd文件中的1位数或两位数。

[root@localhost tuser1]# grep -o "\<[[:digit:]]\{1,2\}\>" /etc/passwd
0
0
1
1
2
2
3
4
4
7
5
0
6
0
7
0
8
12
11
0
12
14
50
99
99
81
81
89
89
74
74
48
48
[root@centos7 ~]#chown -R hadoop:hadoop /home/hadoop/

[root@centos7 ~]#ll -a /home/hadoop/

total 12

drwx------. 3 hadoop hadoop 78 Jul 14 20:24 .

drwxr-xr-x. 12 root root 147 Jul 14 20:24 ..

-rw-r--r--. 1 hadoop hadoop 18 Jul 14 20:24 .bash_logout

-rw-r--r--. 1 hadoop hadoop 193 Jul 14 20:24 .bash_profile

-rw-r--r--. 1 hadoop hadoop 231 Jul 14 20:24 .bashrc

drwxr-xr-x. 4 hadoop hadoop 39 Jul 14 20:24 .mozilla
![](https://github.com/sfz0311/Pictures/raw/master/week4_Q5.PNG)

展示/boot/grub/grub.conf中以至少贰个空白字符起先的行;

redhat柒版本未有/boot/grub/grub.conf文件,替换来/boot/grub2/grub.cfg

 方式1:grep "^[[:space:]]\{1,\}"/boot/grub2/grub.cfg
----------------------------------------
[root@localhost ~]# grep "^[[:space:]]\{1,\}" /boot/grub2/grub.cfg
 load_env
  set default="${next_entry}"
  set next_entry=
  save_env next_entry
  set boot_once=true
  set default="${saved_entry}"
 menuentry_id_option="--id"
----------------------------------------
 方式2:grep "^[[:space:]]\+" /boot/grub2/grub.cfg
----------------------------------------
[root@localhost ~]# grep "^[[:space:]]\+" /boot/grub2/grub.cfg
 load_env
  set default="${next_entry}"
  set next_entry=
  save_env next_entry
  set boot_once=true
  set default="${saved_entry}"
 menuentry_id_option="--id"
----------------------------------------

拾、呈现/boot/grub/grub.conf中以至少多少个空白字符初步的行。

[root@localhost /]# grep "^[[:space:]]\+" /boot/grub/gurb.conf

6.展现/proc/meminfo文件中以大写或小写S起首的行;用三种方法;

  1. 来得/proc/meminfo文件中以大写或小写S开端的行;用三种方法;

显示/etc/rc.d/rc.sysinit文件中以#起先,前边跟至少三个空白字符,而后又有最少2个非空白字符的行;

redhat柒版本未有/etc/rc.d/sysinit文件,替换来 /etc/rc.d/rc.local

grep "^#[[:space:]]\{1,\}[^[:space:]]\{1,\}"  /etc/rc.d/sysinit
----------------------------------------
[root@localhost ~]# grep "^#[[:space:]]\{1,\}[^[:space:]]\{1,\}"  /etc/rc.d/rc.local 
# THIS FILE IS ADDED FOR COMPATIBILITY PURPOSES
# It is highly advisable to create own systemd services or udev rules
# to run scripts during boot instead of using this file.
# In constrast to previous versions due to parallel execution during boot 
# this script will NOT be run after all other services.
# Please note that you must run 'chmod +x /etc/rc.d/rc.local' to ensure
# that this script will be executed during boot.
----------------------------------------

1一、呈现/etc/rc.d/rc.sysinit文件中以#发端,前面跟至少2个空白字符,而后又有最少2个非空白字符的行。

[root@localhost /]# cat /etc/rc.d/rc.sysinit |grep "^#[[:space:]]\+[^[:space:]]"

首先种方法:

![](https://github.com/sfz0311/Pictures/raw/master/week4_Q6.PNG)

打出netstat -tan命令执行结果中以‘LISTEN’,后或跟空白字符结尾的行;

netstat -tan | grep  "LISTEN*[[:space:]]"
----------------------------------------
[root@localhost ~]# netstat -tan | grep  "LISTEN*[[:space:]]"
tcp        0      0 127.0.0.1:25            0.0.0.0:*               LISTEN     
tcp        0      0 0.0.0.0:38810           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     
tcp6       0      0 ::1:25                  :::*                    LISTEN     
tcp6       0      0 :::111                  :::*                    LISTEN     
tcp6       0      0 :::36628                :::*                    LISTEN     
tcp6       0      0 :::22                   :::*                    LISTEN     
tcp6       0      0 ::1:631                 :::*                    LISTEN     
----------------------------------------

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 tuser1]# netstat -tan|grep "LISTEN[[:space:]]*$" |cat -E
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 :::22                   :::*                    LISTEN     $
tcp6       0      0 ::1:25                  :::*                    LISTEN     $
[root@centos7 ~]#grep ^[sS] /proc/meminfo 

SwapCached: 0 kB

SwapTotal: 2097148 kB

SwapFree: 2097148 kB

Shmem: 7416 kB

Slab: 75744 kB

SReclaimable: 28976 kB

SUnreclaim: 46768 kB
  1. 展现/etc/passwd文件中其暗中同意shell为非/sbin/nologin的用户

丰盛用户bash, testbash, basher, nologin (此一个用户的shell为/sbin/nologin),而后找出脚下系统上其用户名和暗许shell相同的用户的新闻;

useradd   bash   
----------------------------------------
[root@localhost ~]# id bash
uid=2006(bash) gid=2006(bash) groups=2006(bash)
----------------------------------------
useradd  testbash  
----------------------------------------
[root@localhost ~]# id testbash
uid=2007(testbash) gid=2007(testbash) groups=2007(testbash)
----------------------------------------
useradd  basher 
----------------------------------------
[root@localhost ~]# id basher
uid=2008(basher) gid=2008(basher) groups=2008(basher)
----------------------------------------
useradd -s /sbin/nologin nologin
----------------------------------------
[root@localhost ~]# grep "nologin" /etc/passwd | tail -1
nologin:x:2009:2009::/home/nologin:/sbin/nologin
----------------------------------------
grep  "^\([[:alnum:]]\)\{1,\}:.*\1$"  /etc/passwd
----------------------------------------
[root@localhost ~]# grep  "^\([[:alnum:]]\)\{1,\}:.*\1$"  /etc/passwd
bin:x:1:1:bin:/bin:/sbin/nologin
daemon:x:2:2:daemon:/sbin:/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
bash:x:2006:2006::/home/bash:/bin/bash
testbash:x:2007:2007::/home/testbash:/bin/bash
nologin:x:2009:2009::/home/nologin:/sbin/nologin
----------------------------------------

一三、添加用户bash, testbash, basher, nologin (此一个用户的shell为/sbin/nologin),而后找出脚下系统上其用户名和暗中认可shell相同的用户的信息。

[root@localhost /]# cat /etc/passwd|egrep "^([^:]+\>).*\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

其次种方式:

![](https://github.com/sfz0311/Pictures/raw/master/week4_Q7.PNG)
[root@centos7 ~]#grep -i ^s /proc/meminfo 

SwapCached: 0 kB

SwapTotal: 2097148 kB

SwapFree: 2097148 kB

Shmem: 7416 kB

Slab: 75744 kB

SReclaimable: 28976 kB

SUnreclaim: 46768 kB
  1. 展现/etc/passwd文件中其暗中同意shell为/bin/bash的用户

7.突显/etc/passwd文件中其暗中认可shell为非/sbin/nologin的用户;

![](https://github.com/sfz0311/Pictures/raw/master/week4_Q8.PNG)
[root@centos7 ~]#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

wang:x:1000:1000:wang:/home/wang:/bin/bash

gentoo:x:4001:4001::/home/gentoo:/bin/bash

fedora:x:4002:4002:Fedora Core:/home/fedora:/bin/tcsh

user2:x:4004:4004::/home/user2:/bin/bash

centos:x:4005:4005::/home/centos:/bin/bash

mageia:x:1100:1100::/home/linux:/bin/bash

slackware:x:2002:2016::/home/slackware:/bin/tcsh

hadoop:x:2003:5004::/home/hadoop:/bin/bash
  1. 找出/etc/passwd文件中的1位数或两位数

捌.显示/etc/passwd文件中其暗中认可shell为/bin/bash的用户;

![](https://github.com/sfz0311/Pictures/raw/master/week4_Q9.PNG)
[root@centos7 ~]#grep /bin/bash$ /etc/passwd | cut -d: -f1

root

wang

gentoo

user2

centos

mageia

hadoop
  1. 浮现/boot/grub/grub.conf中以至少贰个空白字符初阶的行

玖.找出/etc/passwd文件中的一个人数或两位数;

![](https://github.com/sfz0311/Pictures/raw/master/week4_Q10.PNG)

方式1:

  1. 展现/etc/rc.d/rc.sysinit文件中以#初步,前面跟至少一个空白字符,而后又有最少1个非空白字符的行
[root@centos7 ~]#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

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

saslauth:x:996:76:Saslauthd user:/run/saslauthd:/sbin/nologin

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

ntp:x:38:38::/etc/ntp:/sbin/nologin

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

radvd:x:75:75:radvd user:/:/sbin/nologin

gdm:x:42:42::/var/lib/gdm:/sbin/nologin

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

avahi:x:70:70:Avahi mDNS/DNS-SD Stack:/var/run/avahi-daemon:/sbin/nologin

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

tcpdump:x:72:72::/:/sbin/nologin
![](https://github.com/sfz0311/Pictures/raw/master/week4_Q11.PNG)

方式2:

  1. 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@centos7 ~]#grep "\<[0-9][0-9]\?\>" /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

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

saslauth:x:996:76:Saslauthd user:/run/saslauthd:/sbin/nologin

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

ntp:x:38:38::/etc/ntp:/sbin/nologin

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

radvd:x:75:75:radvd user:/:/sbin/nologin

gdm:x:42:42::/var/lib/gdm:/sbin/nologin

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

avahi:x:70:70:Avahi mDNS/DNS-SD Stack:/var/run/avahi-daemon:/sbin/nologin

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

tcpdump:x:72:72::/:/sbin/nologin
![](https://github.com/sfz0311/Pictures/raw/master/week4_Q12.PNG)

10.显示/boot/grub/grub.conf中以至少二个空白字符初阶的行;

  1. 加上用户bash, testbash, basher, nologin
    (此3个用户的shell为/sbin/nologin),而后找出当下系统上其用户名和默许shell相同的用户的新闻

方式1:

![](https://github.com/sfz0311/Pictures/raw/master/week4_Q13.PNG)
[root@centos6 ~]#grep "^[[:space:]]\+" /boot/grub/grub.conf 

          title CentOS 6 (2.6.32-696.el6.x86_64)

        root (hd0,0)

        kernel /vmlinuz-2.6.32-696.el6.x86_64 ro root=UUID=8b390a6d-81d8-4c7d-a263-1aec5212b535 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-2.6.32-696.el6.x86_64.img
  1. 来得/proc/meminfo文件中以大写或小写S开始的行;用三种方法;

方式2:

![](https://github.com/sfz0311/Pictures/raw/master/week4_Q14.PNG)
[root@centos6 ~]#grep "^[[:space:]]\{1,\}" /boot/grub/grub.conf

          title CentOS 6 (2.6.32-696.el6.x86_64)

        root (hd0,0)

        kernel /vmlinuz-2.6.32-696.el6.x86_64 ro root=UUID=8b390a6d-81d8-4c7d-a263-1aec5212b535 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-2.6.32-696.el6.x86_64.img
  1. 突显/etc/passwd文件中其暗许shell为非/sbin/nologin的用户

1一.显示/etc/rc.d/rc.sysinit文件中以#开首,前边跟至少三个空白字符,而后又有最少八个非空白字符的行;

![](https://github.com/sfz0311/Pictures/raw/master/week4_Q15.PNG)
[root@centos6 ~]#grep "^#[[:space:]]\{1,\}[^[:space:]]\{1,\}" /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).

# Check to see if a full relabel is needed

# Update quotas if necessary

# 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
  1. 展现/etc/passwd文件中其默许shell为/bin/bash的用户

1二.打出netstat -tan命令执行结果中以‘LISTEN’,后或跟空白字符结尾的行;

![](https://github.com/sfz0311/Pictures/raw/master/week4_Q16.PNG)
[root@centos7 ~]#netstat -tan | grep "LISTEN*[[:space:]]"

tcp 0 0 0.0.0.0:111 0.0.0.0:* LISTEN     

tcp 0 0 192.168.122.1:53 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     

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

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

tcp6 0 0 ::1:631 :::* LISTEN     

tcp6 0 0 ::1:25 :::* LISTEN 
  1. 找出/etc/passwd文件中的一个人数或两位数

一叁.添加用户bash, testbash, basher, nologin
(此一个用户的shell为/sbin/nologin),而后找出脚下系统上其用户名和默许shell相同的用户的音信;

![](https://github.com/sfz0311/Pictures/raw/master/week4_Q17.PNG)
[root@centos7 ~]#grep "^\([[:alnum:]]\+\)\>.*\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

[root@centos7 ~]#grep -E "^([[: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

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