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。
~]# cp -r /etc/skel/ /home/tuser1~]# cd /home/tuser1
tuser1]# ll -a
总用量 12
drwxr-xr-x. 2 root root 59 12月 22 02:34 .
drwxr-xr-x. 6 root root 56 12月 22 02:34 ..
-rw-r--r--. 1 root root 18 12月 22 02:34 .bash_logout
-rw-r--r--. 1 root root 193 12月 22 02:34 .bash_profile
-rw-r--r--. 1 root root 231 12月 22 02:34 .bashrc
tuser1]# cd ..
home]# chmod -R g=-,o=- tuser1/
home]# ll -d tuser1/
drwx------. 2 root root 59 12月 22 02:34 tuser1/
]# cd /home/tuser1/
tuser1]# ll -a
总用量 12
drwx------. 2 root root 59 12月 22 02:34 .
drwxr-xr-x. 6 root root 56 12月 22 02:34 ..
-rw-------. 1 root root 18 12月 22 02:34 .bash_logout
-rw-------. 1 root root 193 12月 22 02:34 .bash_profile
-rw-------. 1 root root 231 12月 22 02:34 .bashrc
2、编辑/etc/group文件,添加组hadoop。
~]# tail -1 /etc/grouphadoop:x:1003
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。
~]# tail -1 /etc/passwdhadoop:x:1003:1003:/home/hadoop:/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。
~]# cp -r /etc/skel/ /home/hadoop~]# chmod -R g=-,o=- /home/hadoop
5、修改/home/hadoop目录及其内部所有文件的属主为hadoop,属组为hadoop。
~]# chown -R hadoop:hadoop /home/hadoop~]# ll -d /home/hadoop
drwx------. 2 hadoop hadoop 59 12月 22 02:42 /home/hadoop
hadoop]# ll -a
总用量 12
drwx------. 2 hadoop hadoop 59 12月 22 02:42 .
drwxr-xr-x. 7 root root 69 12月 22 02:42 ..
-rw-------. 1 hadoop hadoop 18 12月 22 02:42 .bash_logout
-rw-------. 1 hadoop hadoop 193 12月 22 02:42 .bash_profile
-rw-------. 1 hadoop hadoop 231 12月 22 02:42 .bashrc
6、显示/proc/meminfo文件中以大写或小写S开头的行;用两种方式;
(1)~]# grep -i '^s' /proc/meminfo
SwapCached: 0 kB
SwapTotal: 2097148 kB
SwapFree: 2097148 kB
Shmem: 31856 kB
Slab: 210572 kB
SReclaimable: 154096 kB
SUnreclaim: 56476 kB
(2)
~]# egrep '^(s|S)' /proc/meminfo
SwapCached: 0 kB
SwapTotal: 2097148 kB
SwapFree: 2097148 kB
Shmem: 31856 kB
Slab: 210580 kB
SReclaimable: 154104 kB
SUnreclaim: 56476 kB
(3)
~]# grep '^[sS]' /proc/meminfo
SwapCached: 0 kB
SwapTotal: 2097148 kB
SwapFree: 2097148 kB
Shmem: 31856 kB
Slab: 210572 kB
SReclaimable: 154112 kB
SUnreclaim: 56460 kB
(4)
~]# awk '/^[sS]/ {print $0}' /proc/meminfo
SwapCached: 0 kB
SwapTotal: 2097148 kB
SwapFree: 2097148 kB
Shmem: 31856 kB
Slab: 210572 kB
SReclaimable: 154112 kB
SUnreclaim: 56460 kB
(5)
~]# sed -n '/^[sS]/ p' /proc/meminfo
SwapCached: 0 kB
SwapTotal: 2097148 kB
SwapFree: 2097148 kB
Shmem: 31856 kB
Slab: 210572 kB
SReclaimable: 154112 kB
SUnreclaim: 56460 kB
7、显示/etc/passwd文件中其默认shell为非/sbin/nologin的用户;
~]# grep -v '/sbin/nologin' /etc/passwdroot: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
elsearch:x:1000:1000::/home/elsearch:/bin/bash
nginx:x:1001:1001::/home/nginx:/bin/bash
www:x:1002:1002::/home/www:/bin/bash
hadoop:x:1003:1003:/home/hadoop:/bin/bash
~]# awk -F ':' '{if ($7 != "/sbin/nologin")print $0}' /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
elsearch:x:1000:1000::/home/elsearch:/bin/bash
nginx:x:1001:1001::/home/nginx:/bin/bash
www:x:1002:1002::/home/www:/bin/bash
hadoop:x:1003:1003:/home/hadoop:/bin/bash
8、显示/etc/passwd文件中其默认shell为/bin/bash的用户;
~]# grep '/bin/bash' /etc/passwdroot:x:0:0:root:/root:/bin/bash
elsearch:x:1000:1000::/home/elsearch:/bin/bash
nginx:x:1001:1001::/home/nginx:/bin/bash
www:x:1002:1002::/home/www:/bin/bash
hadoop:x:1003:1003:/home/hadoop:/bin/bash
~]# awk -F ':' '{if ($7 == "/bin/bash")print $0}' /etc/passwd
root:x:0:0:root:/root:/bin/bash
elsearch:x:1000:1000::/home/elsearch:/bin/bash
nginx:x:1001:1001::/home/nginx:/bin/bash
www:x:1002:1002::/home/www:/bin/bash
~]# sed -n "/\/bin\/bash/ p" /etc/passwd
root:x:0:0:root:/root:/bin/bash
elsearch:x:1000:1000::/home/elsearch:/bin/bash
nginx:x:1001:1001::/home/nginx:/bin/bash
www:x:1002:1002::/home/www:/bin/bash
hadoop:x:1003:1003:/home/hadoop:/bin/bash
9、找出/etc/passwd文件中的一位数或两位数;
~]# egrep "\<[[:digit:]]{1,2}\>" /etc//passwdroot: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
apache:x:48:48:Apache:/usr/share/httpd:/sbin/nologin
mysql:x:27:27:MariaDB Server:/var/lib/mysql:/sbin/nologin
tcpdump:x:72:72::/:/sbin/nologin
ntp:x:38:38::/etc/ntp:/sbin/nologin
10、显示/boot/grub/grub.conf中以至少一个空白字符开头的行;
~]# grep '^[[:space:]]\+' /boot/grub/grub.conf11、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;
~]# grep "^#[[:space:]]\+[[:graph:]]\+" /etc/rc.d/rc.sysinit12、打出netstat -tan命令执行结果中以‘LISTEN’跟0、1或多个空白字符结尾的行
~]# netstat -ant | grep 'LISTEN[[:space:]]* '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;
~]# grep '^\(.*\):.*\1$' /etc/passwdsync: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:1004:1004::/home/bash:/bin/bash
nologin:x:1007:1007::/home/nologin:/sbin/nologin