View network card information
- ifconfig (ipconfig for Windows system)
System Information Command
- uname [-a] -system , hostname
- uptime -system load (the first line of the top command, the top command displays system resources in real time)
- free[-h] -memory usage
- who -Check which users are logged in to the terminal (the GUI in RHEL8 is only one user, who is before restarting)
- last- login information
- history -commands that have been run (use !<num> to run the commands corresponding to <num>)
* sosreport -package system information (RedHat has it, CentOS should not)File and directory operations
* pwd -display the current directory
- cd -switch directory ("-" switch to the last directory)
* ls -list files in the current directory [-a] including hidden [-l] including detailed information ("-l" = "ll") - cat- (usually used for small files) display file content
- more- (can be used for small/large files) Display the content of the file by turning pages
- head -[-n]_<num>__<file>_Display the first <num> lines of the file
- tail -[-n]_<num>__<file>_Display the last <num> line of the file
- tr -the content of the converted file
- wc -[-l] Statistics line [-w] Word [-c] Byte count
- stat<fileName>- show file details
Atime-last access time
Ctime-change file attributes and permissions time
Mtime-modify file content time - cut- [-d]: [-f]<num> <fileName>- Use ":" as the interval to extract the information in column <num>
- diff -[–brief] Show whether they are the same or not [-c] Show specific differences
- touch <fileName>- Create file[-d] "<time>"_<fileName>_ can be used to modify Atime and Ctime
- mkdir -[-p] Create related directories
- cp -copy files
- mv -move file (move to the same directory = rename)
- rm -delete file
- dd -if (input file) of (output file) bs (bytes) count (times)
- file** <fileName>View file type**
- grep <keyword>__<fileName>- Extract the line in the fileName where the keyword is located [-n] Display the line number
- find find file
TAR compression
[-c] Package
[-x] Unzip
[-z] gzip
[-j] bzip2
[-v] Show progress
[-C] Specify the path
