第四周作业
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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。
（1）复制/etc/skel目录为/home/tuser1
[[email protected] ~]# cp -r /etc/skel/ /home [[email protected] ~]# mv /home/skel /home/tuser1 [[email protected] ~]# ll -a /home/tuser1/ total 28 drwxr-xr-x. 4 root root 4096 Aug 26 09:10 . drwxr-xr-x. 14 root root 4096 Aug 26 09:11 .. -rw-r--r--. 1 root root 18 Aug 26 09:10 .bash_logout -rw-r--r--. 1 root root 176 Aug 26 09:10 .bash_profile -rw-r--r--. 1 root root 124 Aug 26 09:10 .bashrc drwxr-xr-x. 2 root root 4096 Aug 26 09:10 .gnome2 drwxr-xr-x. 4 root root 4096 Aug 26 09:10 .mozilla
（2）改变/home/tuser1访问权限
[[email protected] ~]# chmod -R g-r,o-r /home/tuser1
（3）结果验证
[[email protected] ~]# ll -a /home/tuser1/ total 28 drwx--x--x. 4 root root 4096 Aug 26 09:10 . drwxr-xr-x. 14 root root 4096 Aug 26 09:11 .. -rw-------. 1 root root 18 Aug 26 09:10 .bash_logout -rw-------. 1 root root 176 Aug 26 09:10 .bash_profile -rw-------. 1 root root 124 Aug 26 09:10 .bashrc drwx--x--x. 2 root root 4096 Aug 26 09:10 .gnome2 drwx--x--x. 4 root root 4096 Aug 26 09:10 .mozilla
2、编辑/etc/group文件，添加组hadoop。
[[email protected] ~]# echo ‘hadoop:x:2500:‘ >> /etc/group [[email protected] ~]# cat /etc/group | grep hadoop hadoop:x:2500:
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] ~]# echo ‘hadoop:x:2500:2500::/home/hadoop:/bin/bash‘ >> /etc/passwd [[email protected] ~]# cat /etc/passwd | grep hadoop hadoop:x:2500:2500::/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。
（1）复制/etc/skel目录为/home/hadoop
[[email protected] ~]# cp -r /etc/skel/ /home [[email protected] ~]# mv /home/skel /home/hadoop [[email protected] ~]# ll -a /home/hadoop/ total 28 drwxr-xr-x. 4 root root 4096 Aug 26 09:10 . drwxr-xr-x. 14 root root 4096 Aug 26 09:11 .. -rw-r--r--. 1 root root 18 Aug 26 09:10 .bash_logout -rw-r--r--. 1 root root 176 Aug 26 09:10 .bash_profile -rw-r--r--. 1 root root 124 Aug 26 09:10 .bashrc drwxr-xr-x. 2 root root 4096 Aug 26 09:10 .gnome2 drwxr-xr-x. 4 root root 4096 Aug 26 09:10 .mozilla
（2）改变/home/hadoop访问权限
[[email protected] ~]# chmod -R g-r,o-r /home/hadoop
（3）结果验证
[[email protected] ~]# ll -a /home/hadoop/ total 28 drwx--x--x. 4 root root 4096 Aug 26 09:10 . drwxr-xr-x. 14 root root 4096 Aug 26 09:11 .. -rw-------. 1 root root 18 Aug 26 09:10 .bash_logout -rw-------. 1 root root 176 Aug 26 09:10 .bash_profile -rw-------. 1 root root 124 Aug 26 09:10 .bashrc drwx--x--x. 2 root root 4096 Aug 26 09:10 .gnome2 drwx--x--x. 4 root root 4096 Aug 26 09:10 .mozilla
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] ~]# chown -R hadoop:hadoop /home/hadoop [[email protected] ~]# ll -a /home/hadoop/ total 28 drwx--x--x. 4 hadoop hadoop 4096 Aug 26 11:04 . drwxr-xr-x. 15 root root 4096 Aug 26 11:04 .. -rw-------. 1 hadoop hadoop 18 Aug 26 11:04 .bash_logout -rw-------. 1 hadoop hadoop 176 Aug 26 11:04 .bash_profile -rw-------. 1 hadoop hadoop 124 Aug 26 11:04 .bashrc drwx--x--x. 2 hadoop hadoop 4096 Aug 26 11:04 .gnome2 drwx--x--x. 4 hadoop hadoop 4096 Aug 26 11:04 .mozilla
6、显示/proc/meminfo文件中以大写或小写S开头的行；用两种方式；
方式1：
[[email protected] ~]# grep -i ‘^s‘ /proc/meminfo SwapCached: 0 kB SwapTotal: 2097148 kB SwapFree: 2097148 kB Shmem: 236 kB Slab: 119296 kB SReclaimable: 56480 kB SUnreclaim: 62816 kB
方式2：
[[email protected] ~]# grep ‘^[s,S]‘ /proc/meminfo SwapCached: 0 kB SwapTotal: 2097148 kB SwapFree: 2097148 kB Shmem: 236 kB Slab: 119348 kB SReclaimable: 56488 kB SUnreclaim: 62860 kB
方式3：
[[email protected] ~]# cat /proc/meminfo |grep "^[s,S]" SwapCached: 0 kB SwapTotal: 2097148 kB SwapFree: 2097148 kB Shmem: 236 kB Slab: 119336 kB SReclaimable: 56484 kB SUnreclaim: 62852 kB
方式4：
[[email protected] ~]# sed -n ‘/^[s,S]/p‘ /proc/meminfo SwapCached: 0 kB SwapTotal: 2097148 kB SwapFree: 2097148 kB Shmem: 236 kB Slab: 119296 kB SReclaimable: 56484 kB SUnreclaim: 62812 kB
方式5：
[[email protected] ~]# awk ‘/^[s,S]/‘ /proc/meminfo
SwapCached: 0 kB SwapTotal: 2097148 kB SwapFree: 2097148 kB Shmem: 236 kB Slab: 119352 kB SReclaimable: 56488 kB SUnreclaim: 62864 kB
7、显示/etc/passwd文件中其默认shell为非/sbin/nologin的用户；
方式1：
[[email protected] ~]# grep -v ‘/sbin/nologin$‘ /etc/passwd root:x:0:0:root:/root:/bin/bash sync:x:5:0:sync:/sbin:/bin/sync shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown halt:x:7:0:halt:/sbin:/sbin/halt suyi:x:500:500:suyi:/home/suyi:/bin/bash testuser:x:501:501::/home/testuser:/bin/bash testuser1:x:502:502::/home/testuser1:/bin/bash testuser2:x:503:503::/home/testuser2:/bin/bash testuser3:x:504:504::/home/testuser3:/bin/bash testuser4:x:505:505::/home/testuser4:/bin/bash testuser5:x:506:506::/home/testuser5:/bin/bash mageia:x:1100:1100::/home/linux:/bin/bash slackware:x:2002:2016::/home/slackware:/bin/tcsh openstack:x:3003:2020::/home/openstack:/bin/bash hadoop:x:2500:2500::/home/hadoop:/bin/bash
方式2：
[[email protected] ~]# cat /etc/passwd |grep -v /sbin/nologin root:x:0:0:root:/root:/bin/bash sync:x:5:0:sync:/sbin:/bin/sync shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown halt:x:7:0:halt:/sbin:/sbin/halt suyi:x:500:500:suyi:/home/suyi:/bin/bash testuser:x:501:501::/home/testuser:/bin/bash testuser1:x:502:502::/home/testuser1:/bin/bash testuser2:x:503:503::/home/testuser2:/bin/bash testuser3:x:504:504::/home/testuser3:/bin/bash testuser4:x:505:505::/home/testuser4:/bin/bash testuser5:x:506:506::/home/testuser5:/bin/bash mageia:x:1100:1100::/home/linux:/bin/bash slackware:x:2002:2016::/home/slackware:/bin/tcsh openstack:x:3003:2020::/home/openstack:/bin/bash hadoop:x:2500:2500::/home/hadoop:/bin/bash
8、显示/etc/passwd文件中其默认shell为/bin/bash的用户；
[[email protected] ~]#grep ‘/bin/bash$‘ /etc/passwd root:x:0:0:root:/root:/bin/bash suyi:x:500:500:suyi:/home/suyi:/bin/bash testuser:x:501:501::/home/testuser:/bin/bash testuser1:x:502:502::/home/testuser1:/bin/bash testuser2:x:503:503::/home/testuser2:/bin/bash testuser3:x:504:504::/home/testuser3:/bin/bash testuser4:x:505:505::/home/testuser4:/bin/bash testuser5:x:506:506::/home/testuser5:/bin/bash mageia:x:1100:1100::/home/linux:/bin/bash openstack:x:3003:2020::/home/openstack:/bin/bash hadoop:x:2500:2500::/home/hadoop:/bin/bash
9、找出/etc/passwd文件中的一位数或两位数；
[[email protected] ~]# 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 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 dbus:x:81:81:System message bus:/:/sbin/nologin rpc:x:32:32:Rpcbind Daemon:/var/cache/rpcbind:/sbin/nologin vcsa:x:69:69:virtual console memory owner:/dev:/sbin/nologin rpcuser:x:29:29:RPC Service User:/var/lib/nfs:/sbin/nologin haldaemon:x:68:68:HAL daemon:/:/sbin/nologin ntp:x:38:38::/etc/ntp:/sbin/nologin apache:x:48:48:Apache:/var/www:/sbin/nologin saslauth:x:498:76:Saslauthd user:/var/empty/saslauth:/sbin/nologin postfix:x:89:89::/var/spool/postfix:/sbin/nologin gdm:x:42:42::/var/lib/gdm:/sbin/nologin sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin tcpdump:x:72:72::/:/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] ~]# grep ‘^[[:space:]]‘ /boot/grub/grub.conf
root (hd0,0) kernel /vmlinuz-2.6.32-642.el6.x86_64 ro root=/dev/mapper/vg_stco6-lv_root nomodeset rd_NO_LUKS LANG=en_US.UTF-8 rd_LVM_LV=vg_stco6/lv_swap rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto rd_LVM_LV=vg_stco6/lv_root 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] ~]# 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. # 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
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] ~]# netstat -tan | grep "LISTEN[[:space:]]*$" tcp 0 0 0.0.0.0:111 0.0.0.0:* LISTEN tcp 0 0 0.0.0.0:38197 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 :::47433 :::* LISTEN tcp 0 0 :::111 :::* LISTEN tcp 0 0 :::22 :::* LISTEN tcp 0 0 ::1:631 :::* 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;
方式1：
[[email protected] ~]# grep ‘^\([^:]\+\):.*/\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:3004:3004::/home/bash:/bin/bash nologin:x:3007:3007::/home/nologin:/sbin/nologin
方式2：
[[email protected] ~]# 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 bash:x:3004:3004::/home/bash:/bin/bash nologin:x:3007:3007::/home/nologin:/sbin/nologin
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