Useful Linux commands

Useful Linux commands-general Linux technology-Linux technology and application information. For more information, see the following. The Linux commands listed below are the most important and useful for beginners and our daily applications.

I often use:
Whereis: Find the location of a command, source code, or manual (man) file, such as whereis java

[The following are commonly used for USB hard disk operations]
Lsusb: List USB devices.
Fdisk: A disk partitioning tool used to list disk devices, such as fdisk-l.
Mount/umount: attach/detach a disk.
Lsof: List open files (especially useful when you cannot umount), for example: lsof | grep mydisk
Kill: send signals to processes (commonly used to kill processes that occupy USB devices discovered by lsof), for example, kill-9 process no.

Arch: displays the architecture type of the processor.
Cat: view the file content, such as cat lorem.txt
Cd: change the working directory, such as cd/bin.
Cksum: Check the CRC checksum and the number of bytes in the file, such as cksum lorem.txt moo.txt.
Cp: copy a file, such as cp lorem.txt copy_of_lorem.txt.
Date: displays the current date and time.
Df: view disk space and available space
Du: view the space occupied by the Directory, such as du-h/bin.
Echo: echo foobar
Groups: view which user groups your account belongs
Hostname: displays the host name.
Id: view the user id, group id, and group of your account
Man: read the manual page, such as man bash.
Md5sum: view the MD5 value of the file, such as md5sum lorem.txt.
Mkdir: create a directory, such as mkdir foobar.
Mv: Move or rename a file, such as mv lorem.txt ipsum.txt
Ping: ping the host, for example, ping-c 2 127.0.0.1.
Ps: view running processes
Pwd: view the current working directory
Sha1sum: view the SHA1 value of the file, for example, sha1sum lorem.txt
Stat: view the File status, such as stat lorem.txt.
Rm: delete a file or directory, such as rm lorem.txt.
Rmdir: delete a directory, such as rmdir foobar
Touch: changes the file access and modification timestamp. If the file does not exist, create it, such as touch lorem.txt.
Tty: view the name of the current terminal
Uname: displays the system, host name, kernel version, date and time, and processor information, such as uname-.
Uptime: view how long the system has been running
W: check who is logged on and what are they doing
Wc: the number of rows in the Statistical File, such as wc-l lorem.txt.
Who: view who has logged on to the system
Whoami: view your user name (or account name)

Whereis is a fast, but not up-to-date query from the database recorded by the system.
Find is a real one-by-one query from the directory, which is slow

PS: Find the man manual using whatis or apropos