& Linux Command

In a system, if we no longer need a user, it is usually necessary to remove it to free up computer resources. We use the Userdel command to remove user actions is very simple. Simply enter the user name after the command. Please try to enter a command in the terminal: Userdel yes. If a prompt appears, the command has been successfully executed. We try to delete a nonexistent user and see what prompts the terminal will give us. Oh！ Terminal says: "User yess does not exist" looks like the information returned by the terminal is very straight ...

Function Description: Send information. Syntax: wall&http://www.aliyun.com/zixun/aggregation/37954.html >nbsp; [Bulletin Information] Supplemental Note: Through the wall directive can send the information to each person who agrees to receive the public information of the terminal user, if does not give its information content, then the wall instruction will read the data from the standard input device, and then transmit the obtained data to all terminal users.

Feature Description: Find and display http://www.aliyun.com/zixun/aggregation/10619.html > user information. Syntax: Fwhios [account name] Supplemental Note: This directive features a bit like the finger instructions, it will go to find and display the specified account user information. The difference is that the Fwhois directive is to receptacle FX whois database to look up, the account name ...

For a computer user, you store, move, and delete files on disk day after day. Of course you care about disk space usage. There is a Shell in Linux that allows users to have a clear picture of how disk space is being used anytime, anywhere. It is the "DF" command. We tried to enter DF in the terminal to see what it would show. Gosh, there's a lot of stuff. But those numbers are so long, do I have to spend a lot of time trying to figure out how much space the disk has? Perhaps DF's lifeline-H parameter can help you. We try to be in the terminal ...

Function Description: Report the status of the program. Syntax: gitps&http://www.aliyun.com/zixun/aggregation/37954.html >nbsp; [ACEFGJLNRSSTUVWXX] [P < Program identification Code] [T < terminal number] [U < account name] Supplemental Note: Gitps is used to report and manage procedures ...

Feature Description: Delete group. Syntax: groupdel&http://www.aliyun.com/zixun/aggregation/37954.html >nbsp; [Group name] Supplemental NOTE: When you need to delete a group from the system, you can do this by using the Groupdel directive. If some users are still included in the group, you must delete the users before you can delete the group.

Function Description: Change the group identifier or name. Syntax: groupmod&http://www.aliyun.com/zixun/aggregation/37954.html >nbsp; [G < Group identification code > <-o>] [-N < new group name] [Group name] Supplemental NOTE: When you need to change the group's identification code or name, you can use Groupmod ...

Function Description: Talk to other users. Syntax: talk&http://www.aliyun.com/zixun/aggregation/37954.html >nbsp; [User Name] [Terminal number] Additional note: You can talk to another user online via the talk directive.

The Groupadd command is used to create user groups on a Linux system. This allows users to get the permissions they have in their group by assigning different permissions to different groups of users and then adding different users to different groups as needed. This approach is handy when there are many users in Linux. The Groupadd command is simple to use, simply enter the user group name after the command. Please try typing in the terminal: Groupadd hello. At this point, we have created a user group called "Hello". For the ...

Function Description: Dump the network transmission data. Syntax: tcpdump&http://www.aliyun.com/zixun/aggregation/37954.html >nbsp; [-ADEFLNNOPQSTVX] Number of [-c< Packets [-DD] [-DDD] [-f< Express Document [-i< Network Interface [-r< Packet File [-s<

Function Description: Deletes the program or work in execution. Syntax: kill&http://www.aliyun.com/zixun/aggregation/37954.html >nbsp; [-s < information name or number] Supplemental description of [program] or kill [-l < info]: Kill to send the specified information to the program. The preset information is sigterm (15 ...).

Function Description: Display the program in a tree chart. Syntax: pstree&http://www.aliyun.com/zixun/aggregation/37954.html >nbsp; [-ACGHLNPUUV] [-H < Program identification Code] [< Program identification code >/< user name "] Supplemental Note: Pstree instruction with ASCII characters display tree structure, clearly express the phase between the program ...

Feature Description: Lists user-related information that failed the login system. Syntax: lastb&http://www.aliyun.com/zixun/aggregation/37954.html >nbsp; [-adrx] [F < record file] [-n < show number of columns] [Account name ...] [Terminal number ...] Supplemental Note: Executes the LASTB instruction separately, it reads in/va ...

Function Description: Adjust priority. Syntax: renice&http://www.aliyun.com/zixun/aggregation/37954.html >nbsp; [Priority level] [G < program group name ...] [-p < Program identification Code ...] [-u < user name ...] Supplementary Note: The renice instruction may readjust the procedure to hold ...

Function Description: Exit the system. Syntax: Logout supplemental NOTE: The logout instruction lets the user exit the system, its function and login instructions correspond to each other.

Feature Description: View system users. Syntax: rwho&http://www.aliyun.com/zixun/aggregation/37954.html >nbsp; [A] Supplemental note: The effect of the rwho directive is similar to that of the WHO directive, but it displays the users of all the hosts on the LAN. The host must provide the functionality of the Rwhod Resident service before using the rwho directive. Parameters:-A lists all users ...

Feature Description: Log in to another group. Syntax: newgrp&http://www.aliyun.com/zixun/aggregation/37954.html >nbsp; [Group name] Supplemental Note: The NEWGRP directive resembles the login instruction, when it is logged into the system again with the same account number, another group name. To use the NEWGRP command to switch groups, you must be a user of that group, otherwise you will not be able to log in to the specified group. Single user should be subordinate to ...

Function Description: System shutdown instructions. Syntax: shutdown&http://www.aliyun.com/zixun/aggregation/37954.html >nbsp; [-EFFHKNR] [t seconds] Time] [Warning message] Supplemental Note: Shutdown instructions can be closed all programs, and according to the needs of users, to reboot or shutdown action. Parameter:-C when executing "s ...

Function Description: Change user identity. Syntax: su&http://www.aliyun.com/zixun/aggregation/37954.html >nbsp; [-FLMP] [--help] [--version] [-] [-c < directive] [-s <shell>] [User Account] Supplemental Note: SU allows users to temporarily change the identity of the login. Changes must be entered to change ...

Function Description: Executes instructions in other capacities. Syntax: sudo&http://www.aliyun.com/zixun/aggregation/37954.html >nbsp; [-BHHPV] [-s <shell>] [-u < user] [directive] or sudo [-KLV] Supplemental Note: sudo allows users to use the other body ...