Introduction
Linux commands are essential tools for operating the Linux system. They can be categorized into several types, each containing a series of related commands used to perform specific system, file, or network operations. Whether managing the CPU, memory, disk drives, keyboard, mouse, or user management, Linux commands are indispensable..
Components of Linux Commands
Linux commands typically consist of three parts: command name, options, and arguments.
Command Name: Represents the Linux system command to be executed.
Options: Used to modify the default behavior of the command, usually starting with “-” or “–“.
Arguments: Specify the objects of the command operation, such as files, directories, etc.
Functions of Linux Commands
Linux commands are a crucial part of the Linux operating system, providing basic management and operational functions for the system. Through Linux commands, users can perform various tasks, such as file management, process management, system information queries, network configuration, etc.
Applications of Linux Commands
System Management: Linux commands can be used to manage system resources, users, and permissions.
File Operations: Linux commands provide rich file operation capabilities. Through Linux commands, users can create, delete, copy, move, and rename files and directories.
Network Management: Linux commands can be used to manage network connections and configure network parameters.
Program Development: Linux commands can be used for compiling, debugging, and running programs.
Scheduled Tasks: Linux commands can be used to set up scheduled tasks to automatically execute specified operations.
System Monitoring: Linux commands can be used to monitor the operating status of the system.
Classification of Linux Commands
Built-in Commands
External Commands
Script Commands
System Management Commands
File Management Commands
Network Commands
Package Management Commands
Text Processing Commands
Classification and Functions of Linux Commands
Built-in Commands
Built-in commands are provided by the Bash Shell (or other shells) themselves and are not executable script files in the file system. They are typically executed within the shell, without starting a separate process, which makes them faster.
External Commands
External commands are standalone executable programs in the Linux operating system, usually located in specific system paths (such as /bin, /usr/bin, etc.). These commands are written by developers to perform specific functions or tasks and cover a wide range of areas.
Script Commands
Script commands usually refer to commands used in shell scripts. Shell scripts are a scripting language used to automate the execution of a series of commands, allowing users to encapsulate multiple commands into a script file for repeated execution. Script commands can be built-in commands, external commands, or a combination of them. By writing shell scripts, users can automate complex tasks and improve work efficiency.
System Management Commands
System management commands are mainly used for managing and maintaining Linux systems. These commands include those for viewing system information (such as uname, hostname), managing system users and groups (such as useradd, groupadd), and monitoring system performance and status (such as top, vmstat), etc.
File Management Commands
File management commands are used to create, delete, copy, move, and rename files and directories in the Linux system. These commands include touch (create file), mkdir (create directory), rm (delete file or directory), cp (copy file or directory), mv (move or rename file or directory), etc.
Network Commands
Network commands are used for network configuration, diagnostics, and management in the Linux system. These commands include those for viewing network interface information (such as ifconfig, ip), testing network connectivity (such as ping), and checking network connection status (such as netstat). Network commands are important tools for Linux users and network administrators for network management and diagnostics.
Text Processing Commands
Text processing commands are used to process and edit text files in the Linux system. These commands include those for viewing file contents (such as cat, more, less), searching text (such as grep), replacing text (such as sed), and formatting text (such as awk). Text processing commands are the basic tools for Linux users for text editing and processing.
In summary, built-in commands, external commands, script commands, system management commands, file management commands, network commands, package management commands, and text processing commands each play different roles and functions in the Linux system, together forming a powerful command system for Linux.
Next, I will explain step by step each classification of Linux commands, what type it is, its purpose, functions, application scenarios, and why it should be used this way.