How to use the command 'rpm2cpio' (with examples)

The rpm2cpio command is a utility used to convert an RPM package file into a cpio archive. RPM (Red Hat Package Manager) files are commonly used in Red Hat-based Linux distributions for software installation. This utility becomes particularly useful when you want to extract files from an RPM package without installing the package itself. The conversion allows you to inspect, modify, or use individual files contained within the RPM package. It’s an essential tool for developers and system administrators managing and customizing software installations on RPM-based systems.

Use case 1: Convert an RPM package to a cpio archive and save it as file.cpio in the current directory

Code:

rpm2cpio path/to/file.rpm > file.cpio

Motivation:

Imagine you are a system administrator who needs to audit or inspect the contents of an RPM package to verify it against security standards before allowing it to be installed on production servers. By converting the RPM to a cpio archive, you can extract its contents and examine them without executing the RPM’s installation scripts. This allows you to ensure the files and dependencies are safe and conform to your policies before proceeding with any system changes.

Explanation:

• rpm2cpio: This is the command itself, initiating the conversion process from an RPM format to a cpio archive.
• path/to/file.rpm: This specifies the path to the RPM file you wish to convert. It acts as the source file for the conversion process.
• >: This is a redirection operator in Unix-like systems that takes the standard output of the command on the left and writes it to a file on the right.
• file.cpio: This is the output filename. The converted cpio content from the RPM package is saved into this file in the current working directory.

Example Output:

After executing the command, you will see a new file named file.cpio in your current directory. While the terminal might not display any output or progress indication, checking your directory should show that the file has been successfully created. You can then use cpio or other related tools to further extract and inspect the contents of file.cpio. The absence of terminal output during the conversion is normal, as the process is directed to silently create the specified cpio file.