Getting started with Linux

1. man provides help explanations for familiar or unfamiliar commands
For example: man ls, you can view the ls-related usage.
Note: Press q or ctrl + c to exit. in linux, you can use ctrl + c to terminate the current program.

2. ls view the directory or file owner * and list the files under any directory
Eg: ls/usr/man
Ls-l
A. d indicates the directory. If it is a "-", it indicates a file. If it is l, it indicates a connection file (link)
B. Permission for file or directory permission. Read (r), write (w), and run (x) respectively ).

3. Copy files using cp
Eg: cp filename1 filename2 // copy filename1 to filename2
Cp 1.c netseek/2.c // copy 1.c to the netseek directory and name it 2.c.

4. rm delete files and directories
Eg: rm 1.c // Delete the. c file.

5. Remove the directory or change the file name.
Eg: mv filename1 filename2 // rename filename1 to filename2
Mv qib. tgz ../qib. tgz // move to the upper-level directory

6. Change the current directory pwd on cd to view the complete path of the current directory
Eg: pwd // view the current directory path
Cd netseek // enter the netseek directory
Cd // exit the current directory
7. cat, more command
Display the content of a file. The two commands are different: cat prints the file content all the time, and more is displayed on the split screen.
For example; cat> 1.c // You can paste the code into the. c file and press ctrl + d to save the code.
Cat 1.c or more 1.c // you can view the content in it.
Gcc-o 1 1.c // compile 1.c into the. exe file. We can use this command to compile the code.

8. chmod command permission modification usage: chmod one-digit octal number filename
Eg: chmod u + x filenmame // you only want to run the command for yourself.
// The u table shows the file owner. g indicates the group in which the file is located. o indicates others. r table is readable, w table is writable, and x table can run.
Chmod g + x filename // the same group of people to execute

9. clear, date command clear: clear screen, equivalent to cls under DOS; date: display the current time.

10. mount a hardware device
Usage: mount [parameter] device load point to be loaded
Eg: mount/dev/cdrom
Cd/mnt/cdrom // enter the cd directory

11. su switches to another person's identity without logging out.
Usage: su-l user name (if the user name defaults, the user name is switched to the root state)
Eg: su-l netseek (switch to the netseek user and the user will be prompted to enter the password)

12. whoami, whereis, which, id
// Whoami: confirm your identity.
// Whereis: queries the directory where the command is located and the directory where the help document is located.
// Which: query the directory where the command is located (similar to whereis)
// Id: print your UID and GID. (UID: Unique id of the user identity. GID: Unique id of the user group. Each user can only have one unique UID and GID .)
Eg: whoami // display your login user name
Whereis bin: the directory where the bin is located. The directory is/usr/local/bin.
Which bin

13. grep, find grep: Text Content Search; find: file or directory name and permission owner matching search
Eg: grep success */* Find all files in the current directory that contain success characters

14. kill can kill a running or dest process.
Eg; ps ax

15. passwd can be used to set a password

16. commands used by the history user
Eg: history // displays the commands used by the user in the past.

17 .!! Execute the last command

18. mkdir command
Eg: mkdir netseek // create the netseek directory

19. tar decompression command
Eg: tar-zxvf nmap-3.45.tgz // extract this to the nmap-3.45 directory

20. finger allows users to query data of other users
Eg: finger // view the user's usage information
Finger root // view the root Information