How to use the command 'namcap' (with examples)

Namcap is a command-line tool that is used to check binary packages and source PKGBUILDs for common packaging mistakes. It is a helpful tool for Arch Linux users and packagers to ensure that their packages are correctly built and comply with the packaging guidelines.

Use case 1: Check a specific PKGBUILD file

Code:

namcap path/to/pkgbuild

Motivation: The motivation for using this example is to check a specific PKGBUILD file for common packaging mistakes. It is useful when you are creating or maintaining an Arch Linux package and want to ensure that the package is correctly built before it is distributed.

Explanation: The command namcap path/to/pkgbuild runs the namcap tool on the specified PKGBUILD file, located at path/to/pkgbuild. The PKGBUILD file is a script that contains information and instructions for building an Arch Linux package. By running namcap on the PKGBUILD file, the tool can analyze the script and check for any common packaging mistakes.

Example output:

path/to/pkgbuild: E: Dependency arch-linux is not required for this package.
path/to/pkgbuild: W: File permissions differ (0444/0644) (symlink)
path/to/pkgbuild: I: Checking runtime dependencies...
path/to/pkgbuild: I: Checking buildtime dependencies...

In this example output, namcap has identified that the package has a dependency on arch-linux which is not required, and it has also found a file with permission differences.

Use case 2: Check a specific package file

Code:

namcap path/to/package.pkg.tar.zst

Motivation: The motivation for using this example is to check a specific package file for common packaging mistakes. Instead of checking the PKGBUILD file, this example allows you to directly analyze the compiled package file.

Explanation: The command namcap path/to/package.pkg.tar.zst runs the namcap tool on the specified package file, located at path/to/package.pkg.tar.zst. The package file is a compressed archive that contains the compiled files and metadata of an Arch Linux package. By running namcap on the package file, the tool can analyze the package and check for any common packaging mistakes.

Example output:

path/to/package.pkg.tar.zst: W: File permissions differ (0444/0644) (symlink)
path/to/package.pkg.tar.zst: E: Missing custom license directory (usr/share/licenses/package)
path/to/package.pkg.tar.zst: I: Checking runtime dependencies...
path/to/package.pkg.tar.zst: I: Checking buildtime dependencies...

In this example output, namcap has identified that the package has a file with permission differences and is missing a custom license directory.

Use case 3: Check a file, printing extra informational messages

Code:

namcap -i path/to/file

Motivation: The motivation for using this example is to check a specific file and print extra informational messages. This can be useful when you want to gather more detailed information about a particular file or analyze it in more depth.

Explanation: The command namcap -i path/to/file runs the namcap tool on the specified file, located at path/to/file, and instructs it to print extra informational messages using the -i option. This allows namcap to provide additional insights and details about the file during the analysis.

Example output:

path/to/file: W: File permissions differ (0444/0644) (symlink)
path/to/file: E: Invalid ELF class (64-bit) (not an ELF file)
path/to/file: I: Checking runtime dependencies...

In this example output, namcap has detected that the file has permission differences and it is not a valid ELF (Executable and Linkable Format) file. Additionally, it provides information about checking the runtime dependencies of the file.

Conclusion:

The namcap command is a useful tool for Arch Linux users and packagers to ensure the correctness of their packages. By using the different examples provided, you can check PKGBUILD files, package files, and individual files for common packaging mistakes. This helps in maintaining the quality and compliance of Arch Linux packages.