Table of Contents (3.3.22)

# Exporting version information

## Getting the last revision number

If you only need the last revision number in your build scripts, you can use the `revno` command to get that value like this:

    $ brz revno
    3104

## Getting more version information

The `version-info` command can be used to output more information about the latest version like this:

    $ brz version-info
    revision-id: pqm@pqm.ubuntu.com-20071211175118-s94sizduj201hrs5
    date: 2007-12-11 17:51:18 +0000
    build-date: 2007-12-13 13:14:51 +1000
    revno: 3104
    branch-nick: brz.dev

You can easily filter that output using operating system tools or scripts. For example:

    $ brz version-info | grep ^date
    date: 2007-12-11 17:51:18 +0000

The `--all` option will actually dump version information about every revision if you need that information for more advanced post-processing.

## Python projects

If using a Makefile to build your project, you can generate the version information file as simply as:

    library/_version.py:
          brz version-info --format python > library/_version.py

This generates a file which contains 3 dictionaries:

> - version_info: A dictionary containing the basic information about the current state.

> - revisions: A dictionary listing all of the revisions in the history of the tree, along with the commit times and commit message. This defaults to being empty unless `--all` or `--include-history` is supplied. This is useful if you want to track what bug fixes, etc, might be included in the released version. But for many projects it is more information than needed.

> - file_revisions: A dictionary listing the last-modified revision for all files in the project. This can be used similarly to how `$Id$` keywords are used in CVS-controlled files. The last modified date can be determined by looking in the `revisions` map. This is also empty by default, and enabled only by `--all` or `--include-file-revisions`.

## Getting version info in other formats

Breezy supports a template-based method for getting version information in arbitrary formats. The `--custom` option to `version-info` can be used by providing a `--template` argument that contains variables that will be expanded based on the status of the working tree. For example, to generate a C header file with a formatted string containing the current revision number:

    brz version-info --custom \
         --template="#define VERSION_INFO \"Project 1.2.3 (r{revno})\"\n" \
         > version_info.h

where the `{revno}` will be replaced by the revision number of the working tree. (If the example above doesn’t work on your OS, try entering the command all on one line.) For more information on the variables that can be used in templates, see Version Info in the Breezy User Reference.

Predefined formats for dumping version information in specific languages are currently in development. Please contact us on the mailing list about your requirements in this area.

## Check clean

Most information about the contents of the project can be cheaply determined by just reading the revision entry. However, it can be useful to know if the working tree was completely up-to-date when it was packaged, or if there was a local modification. By supplying either `--all` or `--check-clean`, `brz` will inspect the working tree, and set the `clean` flag in `version_info`, as well as set entries in `file_revisions` as `modified` where appropriate.