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 -rf /etc/skel /home/tuser1 [root@localhost ~]#chmod -R g-rwx,o-rwx /home/tuser1
2、編輯/etc/group文件，添加組hadoop。
[root@localhost ~]#vim /etc/group [root@localhost ~]#hadoop:x:3005:（在末行加入組名及ID) [root@localhost ~]# cat /etc/group |grep hadoop hadoop:x:3005: [root@localhost ~]# id -g hadoop 3005
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 [root@localhost ~]#hadoop:x:3005:3005::/home/hadoop:/sbin/nologin [root@localhost ~]# id hadoop uid=3005(hadoop) gid=3005(hadoop) groups=3005(hadoop)
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 -rf /etc/skel/ /home/hadoop [root@localhost ~]# chmod -R g-rwx,o-rwx /home/hadoop/ [root@localhost ~]# ll -d /home/hadoop/ drwx------. 4 root root 4096 Jul 8 10:12 /home/hadoop/
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 ~]# ll -d /home/hadoop/ drwx------. 4 root root 4096 Jul 8 10:12 /home/hadoop/ [root@localhost ~]# chown -R hadoop /home/hadoop/ [root@localhost ~]# ll -d /home/hadoop/ drwx------. 4 hadoop root 4096 Jul 8 10:12 /home/hadoop/ [root@localhost ~]# chgrp -R hadoop /home/hadoop/ [root@localhost ~]# ll -d /home/hadoop/ drwx------. 4 hadoop hadoop 4096 Jul 8 10:12 /home/hadoop/
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 ~]# cat /proc/meminfo | grep -E '^(s|S).*' SwapCached: 0 kB SwapTotal: 2064380 kB SwapFree: 2064380 kB Shmem: 1412 kB Slab: 129084 kB SReclaimable: 63872 kB SUnreclaim: 65212 kB [root@localhost ~]# cat /proc/meminfo | grep '^[sS].*' SwapCached: 0 kB SwapTotal: 2064380 kB SwapFree: 2064380 kB Shmem: 1412 kB Slab: 129124 kB SReclaimable: 63884 kB SUnreclaim: 65240 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 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 test:x:500:500::/home/test:/bin/bash shanghai:x:501:501::/home/shanghai:/bin/bash mageia:x:1100:1100::/home/linux:/bin/bash slackware:x:2002:2016::/home/slackware:/bin/tcsh mandriva:x:1005:2016::/home/mandriva:/bin/bash openstack:x:3003:2020::/home/openstack:/bin/bash
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 root:x:0:0:root:/root:/bin/bash test:x:500:500::/home/test:/bin/bash shanghai:x:501:501::/home/shanghai:/bin/bash mageia:x:1100:1100::/home/linux:/bin/bash mandriva:x:1005:2016::/home/mandriva:/bin/bash openstack:x:3003:2020::/home/openstack:/bin/bash
9、找出/etc/passwd文件中的一位數或兩位數；
[root@localhost ~]# 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
...
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-2.6.32-642.el6.x86_64 ro root=/dev/mapper/VolGroup-lv_root rd_NO_LUKS LANG=en_US.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-2.6.32-642.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. ....
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 'LISTEN[[:space:]]\+' 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 0.0.0.0:46074 0.0.0.0:* LISTEN tcp 0 0 :::111 :::* LISTEN tcp 0 0 :::41268 :::* LISTEN tcp 0 0 :::22 :::* LISTEN tcp 0 0 ::1:631 :::* 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 ~]#useradd bash [root@localhost ~]#useradd testbash [root@localhost ~]#useradd basher [root@localhost ~]#useradd -s /sbin/nologin nologin [root@localhost ~]# 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:3006:3006::/home/bash:/bin/bash nologin:x:3009:3009::/home/nologin:/sbin/nologin
14、顯示/proc/meminfo文件中以大寫或小寫S開頭的行；用三種方式；
[root@localhost ~]# cat /proc/meminfo | grep -E '^(s|S).*' SwapCached: 0 kB SwapTotal: 2064380 kB SwapFree: 2064380 kB Shmem: 1412 kB Slab: 129084 kB SReclaimable: 63872 kB SUnreclaim: 65212 kB [root@localhost ~]# cat /proc/meminfo | grep '^[sS].*' SwapCached: 0 kB SwapTotal: 2064380 kB SwapFree: 2064380 kB Shmem: 1412 kB Slab: 129124 kB SReclaimable: 63884 kB SUnreclaim: 65240 kB [root@localhost ~]# grep '\<[sS]' /proc/meminfo SwapCached: 0 kB SwapTotal: 2064380 kB SwapFree: 2064380 kB Shmem: 1412 kB Slab: 129100 kB SReclaimable: 63884 kB SUnreclaim: 65216 kB
15、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 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 test:x:500:500::/home/test:/bin/bash shanghai:x:501:501::/home/shanghai:/bin/bash mageia:x:1100:1100::/home/linux:/bin/bash slackware:x:2002:2016::/home/slackware:/bin/tcsh mandriva:x:1005:2016::/home/mandriva:/bin/bash openstack:x:3003:2020::/home/openstack:/bin/bash bash:x:3006:3006::/home/bash:/bin/bash testbash:x:3007:3007::/home/testbash:/bin/bash basher:x:3008:3008::/home/basher:/bin/bash
16、顯示/etc/passwd文件中其默認shell為/bin/bash的用戶；
[root@localhost ~]# grep "/bin/bash" /etc/passwd root:x:0:0:root:/root:/bin/bash test:x:500:500::/home/test:/bin/bash shanghai:x:501:501::/home/shanghai:/bin/bash mageia:x:1100:1100::/home/linux:/bin/bash mandriva:x:1005:2016::/home/mandriva:/bin/bash openstack:x:3003:2020::/home/openstack:/bin/bash bash:x:3006:3006::/home/bash:/bin/bash testbash:x:3007:3007::/home/testbash:/bin/bash basher:x:3008:3008::/home/basher:/bin/bash
17、找出/etc/passwd文件中的一位數或兩位數；
[root@localhost ~]# 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
....
原創文章，作者：Net21_Lion，如若轉載，請注明出處：http://www.www58058.com/23807
寫的很好，排版也很棒，加油