How to use the command 'pkg_info' in OpenBSD (with examples)

The pkg_info command in OpenBSD is a powerful utility designed to provide detailed information about software packages installed or available on an OpenBSD system. It is often used by system administrators and users to manage and troubleshoot software installations. This command allows users to retrieve information such as package details, dependencies, and version numbers. Additionally, it is closely related to other package management commands like pkg_add and pkg_delete, which are used for installing and removing packages, respectively.

Use case 1: Search for a package using the package name

Code:

pkg_info -Q package

Motivation:

Searching for a package by name is a common task that many system administrators and users need to perform. This is especially the case when you want to confirm whether a specific package is installed on your system or to gather details about a package you wish to install. By using pkg_info -Q package, you can quickly verify the presence of a package, thus aiding in managing dependencies, upgrading software, or resolving conflicts with existing installations.

Explanation:

• pkg_info: This is the primary command used to retrieve package information in OpenBSD.
• -Q: This argument stands for “query.” It instructs the command to search for a package using the provided name in the local package database.
• package: This represents the name of the package you wish to search for. This should be replaced with the actual name of the package you are interested in.

Example Output:

Information for inst: curl-7.79.1
Comment: command line tool and library for transferring data with URL syntax
Description: Curl is a tool for getting files and data using URL syntax...
...

Information for inst: wget-1.21.2
Comment: Retrieve files from the web
Description: GNU Wget is a free utility for non-interactive download of files ...
...

Use case 2: Output a list of installed packages for use with pkg_add -l

Code:

pkg_info -mz

Motivation:

There are situations where you might need to generate a list of all currently installed packages, either for documentation, replication on another system, or for a backup before making significant system changes. This list can be used with the pkg_add -l command to automate the installation of these packages on another system. For instance, when migrating services to a new server or when troubleshooting system issues that require reinstalling packages, having this list can greatly streamline the process.

Explanation:

• pkg_info: This remains the base command used for fetching package information.
• -m: This argument ensures that only user-installed packages are listed, not those that are dependencies automatically installed by the package manager.
• -z: This flag is used to provide the output in a format that can be directly fed into pkg_add -l, enabling automated reinstallation or batch processing of the listed packages.

Example Output:

apache-httpd-2.4.51
bash-5.1.0
git-2.32.0
python-3.9.5
...

Conclusion:

The pkg_info command in OpenBSD is an essential tool for package management. From querying individual packages to exporting a complete list of installed packages, the use cases shown above illustrate how pkg_info can aid in the efficient handling of installed software. Whether you’re verifying package details or preparing for system upgrades or migrations, understanding and utilizing these use cases can simplify your workflow and enhance productivity in managing OpenBSD systems.