How to List Installed Packages with `pkg info` on FreeBSD Operating System

FreeBSD’s package management system is powerful, flexible, and provides users with various tools to monitor and maintain their installed software. Among these tools, pkg info stands out as an essential utility for displaying detailed information about packages installed on your system. This article explores the numerous ways to leverage pkg info for effective package management on FreeBSD systems.

Introduction to FreeBSD’s Package Management

FreeBSD offers two primary methods for software installation: precompiled binary packages via the pkg system, and building from source using the Ports Collection. Regardless of how software was installed, pkg info provides comprehensive tools to investigate and manage these installations.

The pkg info command is a versatile utility that allows users to:

• List all installed packages
• Search for specific packages
• Display detailed information about individual packages
• Verify dependencies and requirements
• Check package origins and installation methods
• Inspect files belonging to specific packages

Basic Usage of pkg info

In its simplest form, running pkg info without any arguments displays a list of all packages installed on your system:

pkg info

This provides a basic overview with each package’s name and version. The output typically looks like:

apache24-2.4.57            Apache HTTP Server
bash-5.2.15                GNU Project's Bourne Again SHell
curl-8.0.1                 Command line tool for transferring data with URLs
git-2.40.1                 Distributed source code management tool
nginx-1.24.0               Robust and small WWW server
php80-8.0.28               PHP Scripting Language (8.0.X branch)
...

While this basic usage is helpful for a quick overview, pkg info truly shines when used with its various options and arguments to extract more specific information.

Filtering Package Lists

Filtering by Package Name

To display information about a specific package, simply provide its name:

pkg info nginx

This will show detailed information about the nginx package if it’s installed.

You can also use pattern matching to find packages matching certain criteria:

pkg info 'php*'

This will list all installed packages whose names start with “php”.

Filtering by Origin

FreeBSD packages have an “origin” which indicates which port they were built from. To filter by origin:

pkg info -o

This displays the package names along with their origins. For example:

apache24-2.4.57: www/apache24
bash-5.2.15: shells/bash
curl-8.0.1: ftp/curl

You can search for packages from a specific origin:

pkg info -o 'lang/*'

This lists all installed packages from the “lang” category in the ports tree.

Displaying Detailed Package Information

Verbose Output

For more comprehensive information about installed packages, use the -v (verbose) flag:

pkg info -v nginx

This displays extended details including:

• Package version
• Maintainer information
• Package description
• Installation date
• License information
• Package size
• Dependencies

For even more detailed information, you can use the -vv or -vvv flags to increase verbosity levels.

Displaying Dependencies

Understanding package dependencies is crucial for system maintenance. To view the dependencies of a package:

pkg info -d nginx

This lists all packages that the specified package depends on to function properly.

Conversely, to see which packages depend on a specified package (reverse dependencies):

pkg info -r nginx

This can be particularly useful when considering removing a package, as it helps identify potential impacts on other installed software.

Listing Package Requirements

For a more comprehensive view of package dependencies, you can use:

pkg info -R nginx

This shows the full dependency chain, including requirements of requirements.

Examining Package Files

Listing Files in a Package

To see all files installed by a specific package:

pkg info -l bash

This lists every file installed by the bash package, including binaries, configuration files, and documentation.

This is particularly useful when:

• Troubleshooting missing files
• Locating configuration files
• Understanding a package’s file structure

Finding Which Package Owns a File

If you have a specific file and need to determine which package installed it:

pkg which /usr/local/bin/bash

While this isn’t strictly a pkg info command, it complements the file listing functionality by working in the reverse direction.

Format Customization

Customizing Output Format

The pkg info command allows customizing the output format using the -O flag followed by a format string:

pkg info -O '%n %v %c' nginx

This would display the name, version, and comment for the nginx package.

Common format specifiers include:

• %n: Package name
• %v: Package version
• %d: Package description
• %m: Package maintainer
• %c: Package comment
• %o: Package origin
• %p: Package prefix
• %q: Architecture
• %w: Home page
• %s: Package size
• %t: Installation timestamp

For example, to create a tab-separated list of all packages with their names, versions, and installation dates:

pkg info -a -O $'%n\t%v\t%t\n'

This type of formatting is particularly useful for scripting or generating reports.

Advanced Usage

Checking Package Annotations

Packages in FreeBSD can have annotations attached to them. To view these annotations:

pkg info -A nginx

Annotations are optional metadata that can be added to packages, often used to store package-specific configuration choices or notes.

Displaying Package Messages

Some packages include post-installation messages with important setup information. To view these messages:

pkg info -D nginx

This displays any messages that were shown during the package installation, which can be useful if you need to reference setup instructions later.

Checking for Shared Libraries

To list the shared libraries provided by a package:

pkg info -B nginx

Conversely, to show which shared libraries a package requires:

pkg info -b nginx

This information is valuable when troubleshooting library dependency issues or compatibility problems.

Practical Applications

Auditing Installed Packages

Although it’s a separate command, pkg audit works well with pkg info for security maintenance:

pkg audit -F
pkg info -a | grep vulnerable

This sequence updates the vulnerability database and then checks if any installed packages have known vulnerabilities.

Finding Orphaned Packages

To identify packages that were installed as dependencies but are no longer required:

pkg autoremove -n

While not strictly a pkg info command, this works with the dependency information tracked by the pkg system.

Creating Package Backups

Before major system changes, it can be useful to save a list of installed packages:

pkg info -q -a > pkg_backup.txt

This creates a file containing just the names of all installed packages, which can be used for restoration:

pkg install -y $(cat pkg_backup.txt)

Obtaining Size Information

To analyze disk usage of installed packages:

pkg info -a -s | sort -hrk 2

This lists all packages with their sizes, sorted from largest to smallest, helping identify which packages consume the most space.

Scripting with pkg info

The structured output from pkg info makes it ideal for use in shell scripts. Here’s a simple example that checks if critical packages are installed and up-to-date:

#!/bin/sh
CRITICAL_PKGS="bash nginx php80 mysql80-server"

for pkg in $CRITICAL_PKGS; do
    if pkg info | grep -q "^$pkg"; then
        echo "$pkg is installed"
    else
        echo "WARNING: $pkg is not installed!"
    fi
done

Another example is creating a simple report of recently installed packages:

#!/bin/sh
# Display packages installed in the last 7 days
CUTOFF=$(date -v-7d +%s)

pkg info -a -O '%n %t' | while read pkg timestamp; do
    if [ $timestamp -gt $CUTOFF ]; then
        echo "Recently installed: $pkg"
    fi
done

Common Issues and Solutions

Package Name Mismatches

Sometimes you may attempt to query a package using a slightly incorrect name. If pkg info packagename returns no results, try using a pattern match:

pkg info -x 'packagename*'

The -x flag performs glob-style pattern matching on package names.

Large Package Lists

On systems with hundreds of installed packages, the output from pkg info can be overwhelming. Use pagination tools:

pkg info | less

Or filter the output to focus on what matters:

pkg info | grep -i database

Inconsistent Database Issues

If pkg info returns errors about the package database, you may need to repair it:

pkg check -d -a
pkg update -f

Conclusion

The pkg info command is a versatile and powerful tool for managing packages on FreeBSD systems. From simple package listing to detailed dependency analysis and custom reporting, mastering this command allows system administrators and users to maintain a cleaner, more secure, and better-organized FreeBSD installation.

By incorporating pkg info into your regular system maintenance routine, you can efficiently track installed software, manage dependencies, troubleshoot issues, and ensure your FreeBSD system remains in optimal condition. The command’s flexibility and comprehensive output make it an indispensable tool for both casual FreeBSD users and professional system administrators.

Whether you’re managing a personal workstation or administering multiple servers, investing time in learning the various options and applications of pkg info will significantly enhance your FreeBSD package management capabilities.