# parse-changelog
[](https://crates.io/crates/parse-changelog)
[](https://docs.rs/parse-changelog)
[](#license)
[](https://www.rust-lang.org)
[](https://github.com/taiki-e/parse-changelog/actions)
Simple changelog parser, written in Rust.
- [Usage (CLI)](#usage-cli)
- [Installation](#installation)
- [Usage (Library)](#usage-library)
- [Supported Format](#supported-format)
- [Related Projects](#related-projects)
- [License](#license)
## Usage (CLI)
`parse-changelog` command parses changelog and outputs a release note for the
specified version.
<details>
<summary>Complete list of options (click to show)</summary>
```console
$ parse-changelog --help
parse-changelog
Parse a changelog and output a release note for the specified version.
USAGE:
parse-changelog [OPTIONS] <PATH> [VERSION]
ARGS:
<PATH> Path to the changelog file (use '-' for standard input)
[VERSION] Specify version (by default, select the latest release)
OPTIONS:
-t, --title Output title instead of a note
--title-no-link Similar to --title, but remove links from title
--json Output JSON representation of all releases in changelog
--version-format <PATTERN> Specify version format
--prefix-format <PATTERN> Specify prefix format [aliases: prefix]
-h, --help Print help information
-V, --version Print version information
```
</details>
### Example: Get Rust's release notes
Get the release note for version 1.46.0 from [Rust's release notes](https://github.com/rust-lang/rust/blob/master/RELEASES.md):
```sh
curl -fsSL https://raw.githubusercontent.com/rust-lang/rust/master/RELEASES.md \
| parse-changelog - 1.46.0
```
[*output of the above command.*](tests/fixtures/rust-1.46.0.md)
### Example: Get Cargo's changelog
In [Cargo's changelog](https://github.com/rust-lang/cargo/blob/master/CHANGELOG.md),
the title starts with "Cargo ", and the patch version is omitted if zero. This is a
format `parse-changelog` don't support by default, so use `--prefix` and
`--version-format` to specify a custom format. For example:
```sh
curl -fsSL https://raw.githubusercontent.com/rust-lang/cargo/master/CHANGELOG.md \
| parse-changelog --prefix 'Cargo ' --version-format '^[0-9]+\.[0-9]+(\.[0-9])?$' - 1.50
```
[*output of the above command.*](tests/fixtures/cargo-1.50.md)
`--prefix` is the same as [`Parser::prefix_format`] and `--version-format` is
the same as [`Parser::version_format`]. See documentation of those methods for
more information.
### Example: Create a new GitHub release from changelog
With [GitHub CLI](https://cli.github.com/manual/gh_release_create):
```sh
tag=...
version=...
# Get notes for $version from CHANGELOG.md.
notes=$(parse-changelog CHANGELOG.md "$version")
# Create a new GitHub release with GitHub CLI.
gh release create "$tag" --title "$version" --notes "$notes"
```
See also [create-gh-release-action].
### Installation
#### From source
```sh
cargo +stable install parse-changelog --locked
```
#### From prebuilt binaries
You can download prebuilt binaries from the [Release page](https://github.com/taiki-e/parse-changelog/releases).
Prebuilt binaries are available for Linux (x86_64 gnu/musl, aarch64 gnu/musl, powerpc64le gnu/musl, riscv64gc gnu/musl, and s390x gnu, musl binaries are static executable), macOS (x86_64, aarch64, and universal), Windows (x86_64 and aarch64, static executable), FreeBSD (x86_64), and illumos (x86_64).
<details>
<summary>Example of script to install from the Release page (click to show)</summary>
```sh
# Get host target
curl --proto '=https' --tlsv1.2 -fsSL "https://github.com/taiki-e/parse-changelog/releases/latest/download/parse-changelog-$host.tar.gz" \
| tar xzf - -C "$HOME/.cargo/bin"
```
</details>
#### Via Homebrew
You can install parse-changelog from the [Homebrew tap maintained by us](https://github.com/taiki-e/homebrew-tap/blob/HEAD/Formula/parse-changelog.rb) (x86_64/AArch64 macOS, x86_64/AArch64 Linux):
```sh
brew install taiki-e/tap/parse-changelog
```
#### Via Scoop (Windows)
You can install parse-changelog from the [Scoop bucket maintained by us](https://github.com/taiki-e/scoop-bucket/blob/HEAD/bucket/parse-changelog.json):
```sh
scoop bucket add taiki-e https://github.com/taiki-e/scoop-bucket
scoop install parse-changelog
```
#### Via cargo-binstall
You can install parse-changelog using [cargo-binstall](https://github.com/cargo-bins/cargo-binstall):
```sh
cargo binstall parse-changelog
```
#### On GitHub Actions
You can use [taiki-e/install-action](https://github.com/taiki-e/install-action) to install prebuilt binaries on Linux, macOS, and Windows.
This makes the installation faster and may avoid the impact of [problems caused by upstream changes](https://github.com/tokio-rs/bytes/issues/506).
```yaml
- uses: taiki-e/install-action@parse-changelog
```
<!-- omit in toc -->
#### Via other package managers
[](https://repology.org/project/parse-changelog/versions)
## Usage (Library)
<!-- tidy:sync-markdown-to-rustdoc:start:src/lib.rs -->
To use this crate as a library, add this to your `Cargo.toml`:
```toml
[dependencies]
parse-changelog = { version = "0.6", default-features = false }
```
> [!NOTE]
> We recommend disabling default features because they enable CLI-related
> dependencies which the library part does not use.
### Examples
```rust
let changelog = "\
## 0.1.2 - 2020-03-01
- Bug fixes.
## 0.1.1 - 2020-02-01
- Added `Foo`.
- Added `Bar`.
## 0.1.0 - 2020-01-01
Initial release
";
// Parse changelog.
let changelog = parse_changelog::parse(changelog).unwrap();
// Get the latest release.
assert_eq!(changelog[0].version, "0.1.2");
assert_eq!(changelog[0].title, "0.1.2 - 2020-03-01");
assert_eq!(changelog[0].notes, "- Bug fixes.");
// Get the specified release.
assert_eq!(changelog["0.1.0"].title, "0.1.0 - 2020-01-01");
assert_eq!(changelog["0.1.0"].notes, "Initial release");
assert_eq!(changelog["0.1.1"].title, "0.1.1 - 2020-02-01");
assert_eq!(
changelog["0.1.1"].notes,
"- Added `Foo`.\n\
- Added `Bar`."
);
```
See [documentation](https://docs.rs/parse-changelog) for more information on
`parse-changelog` as a library.
### Optional features
- **`serde`** — Implements [`serde::Serialize`](https://docs.rs/serde/latest/serde/trait.Serialize.html) trait for parse-changelog types.
## Supported Format
By default, this crate is intended to support markdown-based changelogs
that have the title of each release starts with the version format based on
[Semantic Versioning][semver]. (e.g., [Keep a Changelog][keepachangelog]'s
changelog format.)
### Headings
The heading for each release must be Atx-style (1-6 `#`) or
Setext-style (`=` or `-` in a line under text), and the heading levels
must match with other releases.
Atx-style headings:
```markdown
# 0.1.0
```
```markdown
## 0.1.0
```
Setext-style headings:
```markdown
0.1.0
=====
```
```markdown
0.1.0
-----
```
### Titles
The title of each release must start with a text or a link text (text with
`[` and `]`) that starts with a valid [version format](#versions) or
[prefix format](#prefixes). For example:
```markdown
# [0.2.0]
description...
# 0.1.0
description...
```
#### Prefixes
You can include characters before the version as prefix.
```text
## Version 0.1.0
^^^^^^^^
```
By default only "v", "Version ", "Release ", and "" (no prefix) are
allowed as prefixes.
To customize the prefix format, use the [`Parser::prefix_format`] method (library) or `--prefix-format` option (CLI).
#### Versions
```text
## v0.1.0 -- 2020-01-01
^^^^^
```
The default version format is based on [Semantic Versioning][semver].
This is parsed by using the following regular expression:
```text
- [create-gh-release-action]: GitHub Action for creating GitHub Releases based on changelog. This action uses this crate for changelog parsing.
[`Parser::prefix_format`]: https://docs.rs/parse-changelog/latest/parse_changelog/struct.Parser.html#method.prefix_format
[`Parser::version_format`]: https://docs.rs/parse-changelog/latest/parse_changelog/struct.Parser.html#method.version_format
[create-gh-release-action]: https://github.com/taiki-e/create-gh-release-action
[keepachangelog]: https://keepachangelog.com
[semver]: https://semver.org
## License
Licensed under either of [Apache License, Version 2.0](LICENSE-APACHE) or
[MIT license](LICENSE-MIT) at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted
for inclusion in the work by you, as defined in the Apache-2.0 license, shall
be dual licensed as above, without any additional terms or conditions.