How to Use the `license` Command (with Examples)
The license command is a utility tool designed to assist open-source developers by streamlining the process of adding licenses to their projects. Licensing is crucial for open-source projects as it defines how the project can be used, modified, and distributed by others. This command facilitates the creation of a range of standard licenses with ease, ensuring that a project’s use terms are clearly communicated.
Use case 1: Print a License to stdout, Using the Defaults
Code:
license license_name
Motivation:
When initiating a new open-source project, or when reviewing licenses without making any immediate changes, it’s beneficial to easily view the contents of a standard license. Using this command allows developers to quickly display a license in the terminal, providing an opportunity to review its clauses and understand what permissions and obligations it includes before committing it to their project’s repository.
Explanation:
license: This is the command itself, triggering the action within the tool.license_name: This placeholder should be replaced with the actual name of the license you wish to generate (e.g., MIT, Apache-2.0).
Example Output:
When the command is executed with the license name ‘MIT’, the output will be the full text of the MIT license, customized with the auto-detected author name (from your system’s user name) and the current year.
Use case 2: Generate a License and Save it to a File
Code:
license -o path/to/file license_name
Motivation:
Saving a license directly to a file is a critical step when formalizing an open-source project. By having the license file—often named LICENSE or LICENSE.txt—directly within the project’s repository, the terms of use are immediately accessible to anyone viewing or using the project. This ensures transparency and can prevent potential legal issues regarding the software’s use and distribution.
Explanation:
-o: This flag indicates the output file destination.path/to/file: Replace this with the actual path where you wish to save the generated license file. For instance, ‘LICENSE’ in the root directory of your project repository.license_name: Specify the desired license type, such as ‘GPL-3.0’.
Example Output:
Upon execution, the tool will save the specified license text into the file at the chosen path, populating predefined fields with your system’s author name and the current year.
Use case 3: List All Available Licenses
Code:
license ls
Motivation:
Understanding which licenses are available empowers a developer to make informed decisions about the licensing of their project. Each available license has distinct terms and conditions that might be more or less suitable depending on the nature of the project and its intended usage. Listing all available licenses allows easy comparison and helps in selecting the most appropriate one.
Explanation:
ls: This command lists all available options, akin to a catalog from which the user can select a suitable license type for their project.
Example Output:
The command will display a list of standard open-source licenses available through the tool, including names like MIT, GPL-3.0, Apache-2.0, and BSD-3-Clause.
Use case 4: Generate a License with Custom Author Name and Year
Code:
license --name author --year release_year license_name
Motivation:
When the detected defaults (such as the author’s user name and the current year) do not match the intended information for the project, customization options become invaluable. This command ensures that the license accurately reflects the correct author and the specific year of release, which may differ from the current year or be representative of a project’s collaborative nature or backdated inception.
Explanation:
--name: This flag allows for specification of a custom author’s name.author: The desired author’s name to appear in the license.--year: This flag allows users to specify the release year of the project to be included in the license.release_year: The specific year to be mentioned in the license.license_name: Indicate the license type that needs to be customized (e.g., MIT).
Example Output:
The output of this command will be the full text of the specified license with the custom author and year fields completed as specified, ready for inclusion in the project’s documentation.
Conclusion:
The license command offers a streamlined and efficient way to integrate licenses into open-source projects. Each use case facilitates various aspects of project license management—viewing, creating, saving, listing, and customizing—ensuring developers have the tools necessary to protect and define their work’s usage conditions effectively. By simplifying these tasks, developers can focus more on developing and less on the administrative requirements of open-source licensing.
