parsechangelog.

parsechangelog [options]

-l
    Specifies the changelog file to parse. Defaults to debian/changelog.

--changelog-file
    Long option for specifying the changelog file.

-f
    Sets the format of the changelog file (e.g., dpkg, gnus). Default is dpkg.

--format
    Long option for specifying the changelog format.

-v
    Parses the changelog entry for a specific package version.

--version
    Long option for specifying the version entry to parse.

-s
    Parses entries that are more recent than the specified since-version.

--since
    Long option for parsing entries since a specific version.

-u
    Parses entries up to and including the specified until-version.

--until
    Long option for parsing entries until a specific version.

-o
    Starts parsing from an offset number of entries from the latest one.

--offset
    Long option for specifying an offset from the latest entry.

-c
    Limits the number of changelog entries parsed, starting from the selected point.

--count
    Long option for limiting the number of entries parsed.

-F
    Prints only the value of a specific field (e.g., Version, Distribution, Urgency).

--field
    Long option for printing a specific field's value.

--no-conf
    Prevents parsechangelog from reading any configuration files.

--raw
    Outputs change descriptions without processing them (e.g., line wrapping).

--follow-symlinks
    Follows symbolic links when attempting to locate the changelog file.

parsechangelog is a utility primarily used to extract structured information from Debian changelog files, typically located at debian/changelog within a source package. It can parse various fields such as the package version, target distribution, upload urgency, maintainer details, and the date of the entry, as well as the change descriptions themselves.

While often seen as a standalone command, parsechangelog on many modern Debian-based systems is a symlink or wrapper for dpkg-parsechangelog, which provides more robust and feature-rich parsing capabilities. Its main purpose is to provide machine-readable output for scripts and build tools, enabling automated processes (like dpkg-buildpackage) to determine the current package version and integrate changelog entries into the build and release workflow.

This command is primarily designed for Debian-style changelog files and may not work correctly with other changelog formats. Its exact behavior and available options can vary slightly depending on the specific version of dpkg-dev installed, as parsechangelog is often an alias or symlink to dpkg-parsechangelog. Malformed changelog entries can lead to parsing errors or unexpected output.

When parsechangelog extracts an entry, it can provide various structured fields. Common fields that can be retrieved, especially using the -F or --field option, include:
Version: The package's full version string.
Distribution: The target distribution for the upload (e.g., unstable, stable, testing).
Urgency: The urgency level of the upload (e.g., low, medium, high, emergency).
Maintainer: The name and email address of the package maintainer.
Date: The date and time when the changelog entry was made.
Changes: The actual list of changes or bug fixes described in the entry. This field often contains multi-line text.

One of the most significant uses of parsechangelog is within automated build systems, particularly by dpkg-buildpackage. It allows build scripts to dynamically retrieve the exact version number of the package being built directly from the debian/changelog file. This ensures that the version embedded in the generated Debian package (.deb) is always synchronized with the latest entry in the source's changelog, streamlining the release management process and reducing manual errors.

The functionality to parse Debian changelog files has been a cornerstone of Debian's packaging system since its early inception. The parsechangelog command, or its underlying capabilities, evolved to become a crucial component of the dpkg suite. Over time, dpkg-parsechangelog emerged as the canonical and more feature-rich implementation within the dpkg-dev package, providing robust parsing and advanced options. Its development is inherently tied to the evolution of Debian's packaging standards and tools, ensuring consistent versioning and change tracking for software packages.

dpkg-buildpackage(1), dch(1), dpkg(1), dpkg-source(1)