What is the difference between 'help' and 'man' commands in Linux?

The Difference Between 'help' and 'man' Commands in Linux

In the Linux operating system, both the 'help' and 'man' commands are used to access information about various commands, utilities, and system functions. However, they serve different purposes and provide different types of information.

'help' Command

The 'help' command is a built-in command in the Linux shell, typically the Bash shell. It provides a brief, concise summary of the usage and syntax of a specific command. The 'help' command is particularly useful for getting a quick overview of a command's basic functionality and options.

Here's an example of using the 'help' command to get information about the 'ls' command:

help ls

This will display a short description of the 'ls' command, including its usage, available options, and a brief explanation of what the command does.

The 'help' command is most useful for getting a quick reference on built-in shell commands, such as 'cd', 'echo', 'export', and others. It does not provide detailed information about external commands or system utilities.

'man' Command

The 'man' command, short for 'manual', is used to access the comprehensive, detailed documentation for a specific command, utility, or system function. The 'man' pages, as they are commonly called, provide in-depth information about the command's purpose, syntax, options, and usage examples.

Here's an example of using the 'man' command to get information about the 'ls' command:

man ls

This will display the manual page for the 'ls' command, which includes a detailed description of the command, its available options, and examples of how to use it.

The 'man' pages are organized into different sections, covering various aspects of the Linux system, such as system calls, library functions, file formats, and more. You can navigate through the different sections using the following syntax:

man <section> <command>

For example, to view the manual page for the 'printf' function, which is in section 3 (library functions), you would use:

man 3 printf

The 'man' command is a more comprehensive resource for learning about Linux commands, utilities, and system functions, as it provides detailed information that goes beyond the basic usage summary provided by the 'help' command.

Mermaid Diagram: Comparing 'help' and 'man' Commands

graph TB A[Linux Shell] --> B[help command] A --> C[man command] B --> D[Brief summary of command usage and syntax] C --> E[Detailed documentation on command, utility, or system function] D --> F[Quick reference for built-in shell commands] E --> G[Comprehensive information on commands, utilities, and system functions] F --> H[Limited to built-in shell commands] G --> I[Covers external commands, system utilities, and more]

In summary, the 'help' command provides a quick and concise overview of a command's usage, while the 'man' command offers a more comprehensive and detailed reference for understanding and using Linux commands, utilities, and system functions.