1, copy/etc/skel directory for/home/tuserl,/home/ruserl and its internal files belong to the group and other users do not have any access rights.
2. Edit/etc/group file, add group Hadoop
Step (1) vim/etc/group (2) Press the G key to jump to the last line, press the O key: Create a new row below and enter the input mode input information, ESC exit input mode, press two Z key to save and exit.
3, manually edit/etc/passwd file, add user Hadoop, basic group ID is the Hadoop group ID number, home directory is/home/hadoop
4. Copy the/etc/skel directory as/home/hadoop, requiring that the genus Group and other users of the Hadoop directory be modified without any access rights
5, modify the/home/hadoop directory and all internal files of the owner of Hadoop, belong to the group of Hadoop
6. Displays lines in the/proc/meminfo file that begin with uppercase or lowercase s;
7. Display the user whose default shell is non-/sbin/nologin in the/etc/passwd file
8. Display the user whose default shell is/bin/bash in the/etc/passwd file
9. Find one or two digits in the/etc/passwd file
10. Display lines that begin with at least one whitespace character in/boot/grub/grub.conf
11 displays lines with # Beginning with #, followed by at least one whitespace character, and then at least one non-whitespace character in the/etc/rc.d/rc.sysinit file
12 Netstat-tan command execution results with ' LISTEN ', followed by a line that ends with a blank character
13 Add User Bash, Testbash, basher, Nologin (this one user's shell is/sbin/nologin), and then find information on the current system with the same user name as the default shell user
CP command, grep command example
