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。
[root@localhost tuser1]# cp -r /etc/skel/ /home/tuser1 [root@localhost tuser1]# ll -d /home/tuser1 drwxr-xr-x. 2 root root 59 Dec 23 03:05 /home/tuser1 [root@localhost tuser1]# chmod -R go= /home/tuser1 [root@localhost tuser1]# ll -d /home/tuser1 drwx------. 2 root root 59 Dec 23 03:05 /home/tuser1 [root@localhost tuser1]# ll -A /home/tuser1 total 12 -rw-------. 1 root root 18 Dec 23 03:05 .bash_logout -rw-------. 1 root root 193 Dec 23 03:05 .bash_profile -rw-------. 1 root root 231 Dec 23 03:05 .bashrc
知识点: 文件权限管理
1. ugo表示法
chmod -R go= /home/tuser1
使用技巧: ugo后面为空时,表示相应权限位为空
2. 八进制表示法
3. 参考其他文件权限
2、编辑/etc/group文件，添加组hadoop。
[root@localhost ~]# vim + /etc/group hadoop:x:1011:
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。
[root@localhost ~]# vim + /etc/passwd user110:x:1010:1010::/home/user110:/bin/bash hadoop:x:1011:1011::/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。
[root@localhost ~]# cp -r /etc/skel/ /home/hadoop [root@localhost ~]# chmod -R go= /home/hadoop [root@localhost ~]# ll -d /home/hadoop drwx------. 2 root root 59 Dec 23 03:52 /home/hadoop [root@localhost ~]# ll -A /home/hadoop total 12 -rw-------. 1 root root 18 Dec 23 03:52 .bash_logout -rw-------. 1 root root 193 Dec 23 03:52 .bash_profile -rw-------. 1 root root 231 Dec 23 03:52 .bashrc
5、修改/home/hadoop目录及其内部所有文件的属主为hadoop，属组为hadoop。
[root@localhost ~]# chown -R hadoop:hadoop /home/hadoop/ [root@localhost ~]# ll -d /home/hadoop/ drwx------. 2 hadoop hadoop 59 Dec 23 03:52 /home/hadoop/ [root@localhost ~]# ll -A /home/hadoop/ total 12 -rw-------. 1 hadoop hadoop 18 Dec 23 03:52 .bash_logout -rw-------. 1 hadoop hadoop 193 Dec 23 03:52 .bash_profile -rw-------. 1 hadoop hadoop 231 Dec 23 03:52 .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；
方法1:
[root@localhost ~]# grep '^[Ss]' /proc/meminfo SwapCached: 0 kB SwapTotal: 511996 kB SwapFree: 511996 kB Shmem: 8988 kB Slab: 92240 kB SReclaimable: 55260 kB SUnreclaim: 36980 kB
方法2:
[root@localhost ~]# grep -E '^(S|s)' /proc/meminfo SwapCached: 0 kB SwapTotal: 511996 kB SwapFree: 511996 kB Shmem: 8988 kB Slab: 92240 kB SReclaimable: 55260 kB SUnreclaim: 36980 kB
7、显示/etc/passwd文件中其默认shell为非/sbin/nologin的用户；
[root@localhost ~]# grep -v '/sbin/nologin' /etc/passwd | cut -d: -f1,7 root:/bin/bash sync:/bin/sync shutdown:/sbin/shutdown halt:/sbin/halt han:/bin/bash user101:/bin/bash user102:/bin/bash user103:/bin/bash user104:/bin/bash user105:/bin/bash user106:/bin/bash user107:/bin/bash user108:/bin/bash user109:/bin/bash user110:/bin/bash hadoop:/bin/bash
8、显示/etc/passwd文件中其默认shell为/bin/bash的用户；
[root@localhost ~]# grep '/bin/bash' /etc/passwd | cut -d: -f1,7 root:/bin/bash han:/bin/bash user101:/bin/bash user102:/bin/bash user103:/bin/bash user104:/bin/bash user105:/bin/bash user106:/bin/bash user107:/bin/bash user108:/bin/bash user109:/bin/bash user110:/bin/bash hadoop:/bin/bash
9、找出/etc/passwd文件中的一位数或两位数；
[root@localhost ~]# grep -E '\<[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
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
10、显示/boot/grub/grub.conf中以至少一个空白字符开头的行；
[root@node1 ~]# grep '^[[:space:]]\+' /boot/grub/grub.conf root (hd0,0) kernel /vmlinuz-2.6.32-642.el6.x86_64 ro root=UUID=1cc68cb8-0de5-4cbf-ad1c-b6ed129b1177 rd_NO_LUKS rd_NO_LVM.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；
[root@node1 ~]# 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；
[root@node1 ~]# netstat -tan | grep 'LISTEN[[:space:]]*$' tcp 0 0 0.0.0.0:36863 0.0.0.0:* LISTEN tcp 0 0 0.0.0.0:111 0.0.0.0:* LISTEN tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN tcp 0 0 127.0.0.1:631 0.0.0.0:* LISTEN tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN tcp 0 0 127.0.0.1:6010 0.0.0.0:* LISTEN tcp 0 0 :::55626 :::* LISTEN tcp 0 0 :::111 :::* LISTEN tcp 0 0 :::80 :::* LISTEN tcp 0 0 :::22 :::* LISTEN tcp 0 0 ::1:631 :::* LISTEN tcp 0 0 ::1:25 :::* LISTEN tcp 0 0 ::1:6010 :::* LISTEN
13、添加用户bash, testbash, basher, nologin (此一个用户的shell为/sbin/nologin)，而后找出当前系统上其用户名和默认shell相同的用户的信息；
[root@node1 ~]# useradd bash [root@node1 ~]# useradd testbash [root@node1 ~]# useradd basher [root@node1 ~]# useradd -s /sbin/nologin nologin [root@node1 ~]# tail -4 /etc/passwd bash:x:502:502::/home/bash:/bin/bash testbash:x:503:503::/home/testbash:/bin/bash basher:x:504:504::/home/basher:/bin/bash nologin:x:505:505::/home/nologin:/sbin/nologin [root@node1 ~]# grep -E '^([^:]+)\>.*\1$' /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:502:502::/home/bash:/bin/bash nologin:x:505:505::/home/nologin:/sbin/nologin
14、显示/proc/meminfo文件中以大写或小写S开头的行；用三种方式；
方法1:
[root@localhost ~]# grep '^[Ss]' /proc/meminfo SwapCached: 0 kB SwapTotal: 511996 kB SwapFree: 511996 kB Shmem: 8988 kB Slab: 92240 kB SReclaimable: 55260 kB SUnreclaim: 36980 kB
方法2:
[root@localhost ~]# grep -E '^(S|s)' /proc/meminfo SwapCached: 0 kB SwapTotal: 511996 kB SwapFree: 511996 kB Shmem: 8988 kB Slab: 92240 kB SReclaimable: 55260 kB SUnreclaim: 36980 kB
方法3:
[root@node1 ~]# grep -i '^s' /proc/meminfo SwapCached: 0 kB SwapTotal: 204796 kB SwapFree: 204796 kB Shmem: 1376 kB Slab: 108876 kB SReclaimable: 43916 kB SUnreclaim: 64960 kB
15、显示/etc/passwd文件中其默认shell为非/sbin/nologin的用户；
[root@localhost ~]# grep -v '/sbin/nologin' /etc/passwd | cut -d: -f1,7
16、显示/etc/passwd文件中其默认shell为/bin/bash的用户；
[root@localhost ~]# grep '/bin/bash' /etc/passwd | cut -d: -f1,7
17、找出/etc/passwd文件中的一位数或两位数；
[root@localhost ~]# grep -E '\<[0-9]{1,2}\>' /etc/passwd
原创文章，作者：hansj，如若转载，请注明出处：http://www.178linux.com/64645
