Learning Linux commands is crucial for navigating and managing a Linux system effectively. Below is a list of essential commands that every beginner should know, along with brief explanations of their functions.
1.LS [LIST]
Lists the contents of a directory. It shows files and subdirectories within the current directory.
Usage: ls [options]
Options include -l (detailed list) and -a (show hidden files) .
2.PWD [PRINT WORKING DIRECTORY]
Prints the current working directory, helping users understand their location in the file system.
Usage: pwd .
3.CD [CHANGE DIRECTORY]
Changes the current directory to a specified path, allowing navigation between directories.
Usage: cd [directory] or [path].
4.MKDIR [MAKE DIRECTORY]
Creates a new directory with the specified name.
Usage: mkdir [directory_name] .
5.RMDIR [REMOVE DIRECTORY]
Removes an empty directory from the file system.
Usage: rmdir [directory_name] .
6.RM [REMOVE]
Deletes files or directories. Use with caution, as this action cannot be undone.
Usage: rm [file_name] or rm -r [directory_name] for recursive deletion .
7.CP [COPY]
Copies files or directories from one location to another.
Usage: cp [source] [destination] .
8.MV [MOVE]
Moves or renames files and directories.
Usage: mv [source] [destination] .
9.TOUCH
Creates an empty file or updates the timestamp of an existing file.
Usage: touch [file_name] .
10.CAT [CONCATENATION]
Displays the contents of a file in the terminal window, useful for quick viewing of text files.
Usage: cat [file_name] .
11.MAN [MANUAL]
Accesses the manual pages for other commands, providing detailed information on usage and options.
Usage: man [command_name].
12.GREP
Searches for specific patterns within files or output from other commands, making it invaluable for filtering data.
Usage: grep [pattern] [file_name] or in combination with other commands via pipes .
13.ECHO
Outputs text or variables to the terminal, often used in scripts to display messages or results.
Usage: echo "text" or echo $VARIABLE_NAME to display variable content .
14.CLEAR
Clears the terminal screen, providing a clean workspace for further commands.
Usage: clear .
15.UNAME
Displays system information such as the kernel name and version, useful for understanding your environment setup.
Usage: uname -a for detailed information about the system .
16.LOCATE
Quickly finds files by searching through a pre-built database of file names on the system, which can be updated with the updatedb command.
Usage: locate [file_name] .
17.PROCESS
Displays currently running processes along with their process IDs (PIDs), helping users manage tasks effectively.
Usage: ps aux for detailed information about all processes running under your user account and others' processes if permissions allow .
18.KILL
Terminates processes using their process ID (PID). This is essential for managing unresponsive applications or tasks.
Usage: kill [PID], where PID is obtained from the output of the ps command .
19.WGET
Downloads files from the web directly to your local machine via command line, useful for retrieving scripts or data files quickly without a browser interface.
Usage: wget [URL]
20.SHUTDOWN
Shuts down or reboots the system at a scheduled time or immediately based on user input, important for safely powering off machines in multi-user environments.
Usage: shutdown now to shut down immediately, or specify time like shutdown +10 to shut down after 10 minutes
21.DF [DISK FILESYSTEM]
Reports file system disk space usage, providing insights into available and used space on mounted file systems.
Usage: df -h for human-readable format.
22.DU [DISK USAGE]
Estimates file and directory space usage, helping administrators identify large files or directories consuming disk space.
Usage: du -sh [directory] for summary.
23.CURL
Transfers data from or to a server using various protocols (HTTP, FTP, etc.). It is often used for testing APIs or downloading files.
Usage: curl [options] [URL].
24.TOP
Displays real-time system activity, including CPU and memory usage for running processes. It is an interactive tool that updates automatically.
Usage: top.
25.SERVICE
Purpose: The service command is designed to control services that run in the background, such as web servers or database servers.
26.SUDO
Usage: It is typically used with root privileges, which can be obtained by prefixing commands with sudo.
These commands are vital tools in a system administrator's arsenal, enabling effective management of Linux systems and troubleshooting various issues that may arise in a server environment.
