equery Command: Tutorial & Examples

The equery command is a versatile utility provided by the Gentoo Linux distribution's Portage package management system. It is part of the app-portage/gentoolkit package and is used for querying various aspects of installed packages and the Portage tree. equery makes it easy to get detailed information about packages, dependencies, and use flags, among other things.

What Does equery Do?

The equery command provides detailed information about Gentoo packages. It allows users to:

• Check which files belong to a package.
• Find out which package owns a specific file.
• View package dependencies.
• See USE flags.
• Obtain package descriptions and homepages.

This command is particularly useful for system administrators and users who need to manage and troubleshoot packages on their Gentoo systems.

How equery Works

When you run the equery command, it interacts with the Portage tree and the installed package database to retrieve the requested information. It formats this data in a human-readable way, making package management tasks more straightforward.

Why equery is Important

For Gentoo users, equery is an essential tool because it simplifies the process of managing and troubleshooting packages. Knowing which files belong to which packages, understanding dependencies, and inspecting USE flags can save a lot of time and effort, especially when resolving issues like high load or package conflicts.

How to Use equery and Common Command-Line Parameters

To use equery, you need to have the gentoolkit package installed. You can install it using the following command:

emerge app-portage/gentoolkit

Here are some common equery subcommands and their uses:

• equery list <package>: Lists all installed versions of a package.
• equery files <package>: Lists files installed by a package.
• equery belongs <file>: Finds which package owns a file.
• equery depgraph <package>: Displays dependency graph for a package.
• equery uses <package>: Shows USE flags for a package.
• equery meta <package>: Displays metadata for a package.

Examples

Listing Installed Versions of a Package

equery list vim

Typical output:

* Searching for vim ...
[IP-] [  ] app-editors/vim-8.2.2434:0

Listing Files Installed by a Package

equery files vim

Typical output:

* Contents of app-editors/vim-8.2.2434:

/usr /usr/bin /usr/bin/vim ...

Finding Which Package Owns a File

equery belongs /usr/bin/vim

Typical output:

* Searching for /usr/bin/vim ...
app-editors/vim-8.2.2434 (/usr/bin/vim)

Potential Problems and Pitfalls

While equery is a powerful tool, there are a few common issues you might encounter:

• Permission Denied: Running equery without the necessary permissions might result in errors. Use sudo to run the command as root.
• Outdated Database: Ensure your Portage tree is up to date by running emerge --sync before using equery for accurate results.
• Missing gentoolkit: If equery is not found, make sure gentoolkit is installed using emerge app-portage/gentoolkit.

Conclusion

The equery command is an indispensable tool for managing packages on Gentoo Linux. By mastering equery, you can efficiently query package information, troubleshoot issues, and ensure your system runs smoothly.