How to Generate Man Pages with `help2man` (with examples)

The help2man command is a utility in the GNU software suite designed to create simple manual pages for executables. By extracting information from the --help and --version outputs of a program, help2man automates the creation of man pages, which serve as critical documentation for users to understand the functionality and usage of a program. This command is particularly beneficial for developers seeking to provide quick and consistent documentation with minimal effort.

Use case 1: Generate a man page for an executable

Code:

help2man executable

Motivation:

Developers often want to provide their users with a man page for their software to ensure ease of use and understanding of the software’s functionalities. Man pages serve as a reliable source of information, detailing options, usage, and version details. By using help2man, developers can quickly generate man pages directly from the information already embedded in the software’s help and version outputs, saving time and ensuring consistency.

Explanation:

• help2man: This is the command that initiates the process of creating a man page.
• executable: This represents the program or script for which the man page is to be created. When this program’s --help and --version options are executed, help2man captures the displayed information to generate the corresponding man page.

Example Output:

Executing this command will produce a man page like the following:

.TH EXECUTABLE 1 "2023-10-05" "Executable 1.0" "User Commands"
.SH NAME
executable \- example program
.SH SYNOPSIS
.B executable
[\fIOPTIONS\fR]
.SH DESCRIPTION
Brief description of the executable.
...

Use case 2: Specify the “name” paragraph in the man page

Code:

help2man executable --name name

Motivation:

A well-defined “NAME” section is crucial as it appears first in the man page and gives users a snapshot of what the program is and does. Defining a clear and concise name through help2man helps ensure that users immediately grasp the utility’s purpose.

Explanation:

• help2man: Initiates the man page creation process.
• executable: Specifies the program for which a man page is to be generated.
• --name name: This option allows the user to define the content of the “NAME” section in the man page. The name argument should succinctly encapsulate what the program does.

Example Output:

This generates a man page with a specified name section:

.SH NAME
executable \- specific functionality description
...

Use case 3: Specify the section for the man page

Code:

help2man executable --section section

Motivation:

Man pages are organized into sections, which categorize the type of manual showing whether it’s a command, library, or file format, among others. By default, help2man uses section 1 for general commands, but this option is useful when the executable falls under a different category, allowing for better organization in the manual directories.

Explanation:

• help2man: Starts the man page creation process.
• executable: The program for which a man page is generated.
• --section section: This option specifies which section the man page should belong to. Common sections include 1 (user commands), 5 (file formats), 8 (system management commands), etc.

Example Output:

.TH EXECUTABLE section "2023-10-05" "Executable 1.0" "System Commands"

Use case 4: Output to a file instead of stdout

Code:

help2man executable --output path/to/file

Motivation:

While viewing the man page output directly in the terminal is useful for a quick view, writing it to a file allows for saving, sharing, and further editing. This capability is critical for maintaining documentation in a version-controlled environment or distributing to multiple users.

Explanation:

• help2man: Initiates the man page generation.
• executable: Denotes the program or command for which the man page is to be created.
• --output path/to/file: Redirects the output of the man page to a specified file path. path/to/file is the location where the generated man page content will be stored, enabling you to easily manage and distribute it.

Example Output:

The man page content will be written into the specified file, for example:

path/to/file:
.TH EXECUTABLE 1 "2023-10-05" "Executable 1.0" "User Commands"
...

Use case 5: Display help

Code:

help2man --help

Motivation:

Understanding all available options and functionalities of help2man is essential for optimizing its usage and customizing man pages to better fit your documentation needs. Accessing help information allows users to leverage the command’s full potential.

Explanation:

• help2man: The main command being used.
• --help: This flag provides users with helpful information on how to use help2man, including descriptions of various flags and options available for modifying the output according to user requirements.

Example Output:

help2man - produce simple manual pages from program output
Usage: help2man [OPTION] ... COMMAND ...
...

Conclusion:

The help2man command offers a streamlined and efficient way to create man pages, drawing directly from the output provided by the program’s own help and version functionalities. This automation minimizes the overhead of manual documentation, ensuring that users always have access to current and accurate usage instructions. Whether you’re specifying the name or section of a man page, or simply storing its output in a file, help2man supports a wide range of options to cater to diverse documentation needs. The examples provided in this article demonstrate only a portion of the tool’s capabilities, empowering developers and users alike with easy-to-generate documentation.