w- Displays the currently logged-in user information in the system. ab- Apache server performance testing tool. ld- Links object files to create an executable program. xz- A tool for POSIX platform development with high compression rates. ln- Used to create links for files. ar- Creates or modifies archive files, or extracts from archive files. fg- Brings background jobs to the foreground terminal. wc- Counts the bytes, words, and lines in a file. as- Assembler language compiler. at- Executes a task at a specified time. bc- Arbitrary precision arithmetic calculator. bg- Used to run jobs in the background. ex- Starts the ex editing mode of the vim editor. ed- A line-oriented text editor. tr- Translates, compresses, and deletes characters. nc- Command used to set up routers. nl- Counts the number of lines in a file in Linux. nm- Displays the symbol table of binary object files. od- Outputs the file in octal, hexadecimal, and other encoded formats. su- Used to switch the current user identity to another user. ss- Obtains socket statistics. iproutesh- Shell command interpreter. pv- Displays the progress of commands currently executing in the command line. dd- Copies files and converts and formats the content of the original file. man- Views command help in Linux. sar- System performance monitoring tool. sed- A powerful stream editor. seq- Prints numbers from a start number to an end number with a specified increment. zip- Can be used to decompress files. cut- Joins files and prints to standard output. set- Displays or sets shell attributes and shell variables. col- Filters control characters. pvs- Outputs physical volume information reports. cmp- Compares two files for differences. dig- Domain name query tool. ssh- Client connection tool in the OpenSSH suite. sum- Calculates the checksum of a file and displays the block count. dnf- Next-generation RPM package manager. tac- Outputs a file in reverse order by line. cat- Joins files and prints to standard output. cal- Displays the current calendar or the calendar for a specified date. tee- Redirects data to a given file and the screen. scp- Securely copies files between local and remote hosts. env- Displays the environment variables that exist in the system. tty- Displays the terminal device file name connected to the current standard input. awk- A programming language for processing text and data. atq- Lists the current user’s at job queue. arp- Displays and modifies the IP to MAC address translation table. arj- Used to create and manage .arj compressed files. who- Displays the currently logged-in users. fmt- Reads a file, optimizes it, and outputs it. let- A simple calculator. gcc- C/C++ compiler. gdb- A powerful program debugger. ldd- Prints the shared library dependencies of a program or library file. yes- Repeatedly prints a specified string. git- The most advanced distributed version control system in the world. yum- RPM-based package manager. rev- Outputs the contents of a file in reverse order by character. chfn- Used to change the information displayed by the finger command. bind- Displays or sets the keyboard key functions. dirs- Displays the directory stack. stty- Modifies terminal command line settings. popd- Used to delete records from the directory stack. stat- Displays file status information. pmap- Reports the memory mapping of a process. fc- Modifies and executes historical commands. vi- A powerful text editor. The commands to exit the VI editor in command mode are as follows: :q: If you have not modified the file or have already saved the changes, you can use this command to exit the VI editor. :q!: If you have modified the file but do not want to save those changes, you can use this command to force exit without saving. :wq or ZZ (pressing uppercase Z twice in command mode): If you want to save changes to the file and exit the VI editor, you can use this command. :wq!: This command can force save changes and exit the VI editor even if the file is read-only. 😡: This command has the same function as :wq, which is to save the file and exit the VI editor.