======================
Bazaar in five minutes
======================

Introduction
============

Bazaar is a distributed version control system that makes it easier for
people to work together on software projects.

Over the next five minutes, you'll learn how to put your files under
version control, how to record changes to them, examine your work, publish
it and send your work for merger into a project's trunk.


Installation
============

This guide doesn't describe how to install Bazaar but it's usually very
easy. You can find installation instructions at:

- **GNU/Linux:** Bazaar is probably in your GNU/Linux distribution already.
- **Windows:** `installation instructions for Windows`_.
- **Mac OS X:** `installation instructions for Mac OS X`_.

For other platforms and to install from source code, see the Download_
and Installation_ pages.

.. _installation instructions for Windows: http://wiki.bazaar.canonical.com/WindowsDownloads
.. _installation instructions for Mac OS X: http://wiki.bazaar.canonical.com/MacOSXBundle
.. _Download: http://wiki.bazaar.canonical.com/Download
.. _Installation: http://wiki.bazaar.canonical.com/InstallationFaq


Introducing yourself
====================

Bazaar records changes to source code, and it records who made the change.
The person is identified by their name and email address.  (If you're
concerned about spam, you don't need to use a real address that you
actually read, but the convention is that it looks like an email address.)

Before you start working, let's tell Bazaar who you are.  Using your name
and email address, instead of John Doe's, type::

  $ bzr whoami "John Doe <john.doe@gmail.com>"

You can check what identity is stored in Bazaar's configuration::

  $ bzr whoami
  John Doe <john.doe@gmail.com>


Starting a new project
======================

Let's suppose we want to store a new project under Bazaar.  First, we'll
make a *repository directory* to hold all our work related to this
project, where developers can create branches to test development of
specific features or, more generally, modifications to the working file
set.  

After creating the repository, change to that directory, and create the
project's main trunk branch.

::

  $ bzr init-repo sample
  Shared repository with trees (format: 2a)
  Location:
    shared repository: sample
  $ bzr init sample/trunk
  $ cd sample/trunk
  Created a repository tree (format: 2a)                                         
  Using shared repository: /home/john/sample/


Adding files
============

Now that we have the trunk, we need to move to that directory and
create some example files for the first version of that project.  Create
a file ``test1.txt`` using a text editor (like emacs, nano, or notepad),
and save it.  Then we'll "add" the file, which tells bzr we want it to
track changes::

  bzr add test1.txt

and then commit, which saves a snapshot of all versioned files::

  bzr commit -m "Added first line of text"


Making changes to your files
============================


Let's change a file and commit that change to your branch.

Edit ``test1.txt`` in your favourite editor, then use ``bzr add`` to tell bzr
to track changes to this file ::

  $ echo test test test > test1.txt 
  $ bzr add test1.txt
  adding test1.txt

`bzr diff` shows the changes between the last revision in this branch, and your
current tree (or, with the ``-r`` option, between any two trees). ::

 $ bzr diff
 === modified file 'test1.txt'
 --- test1.txt   2007-10-08 17:56:14 +0000
 +++ test1.txt   2007-10-08 17:46:22 +0000
 @@ -0,0 +1,1 @@
 +test test test

Commit your work to the Bazaar branch::

  $ bzr commit -m "Added first line of text"
  Committing to: /home/john/sample/trunk/                             
  added test1.txt
  Committed revision 1.

Viewing the revision log
========================

You can see the history of your branch by browsing its log::

  $ bzr log
  revno: 1
  committer: John Doe <john.doe@gmail.com>
  branch nick: trunk
  timestamp: Mon 2006-10-08 17:46:22 +0000
  message:
    Initial import


Publishing your branch on Launchpad
===================================

Launchpad is a suite of development and hosting tools for
software projects. You can use it to publish your branch.  (You can 
also publish branches onto your own server or other hosting services.)

The steps to publishing branches on Launchpad are:

1. Create a Launchpad account: visit the `Launchpad login page`_ and choose to create a new account.
    
.. _Launchpad login page: https://launchpad.net/+login
    
2. Bazaar uses the SSH encryption and authentication protocol to connect
   to Launchpad.  You need to first `create an SSH key`_ on your own computer,
   by running the command::
    
       $ ssh-keygen

.. _create an SSH key: https://help.launchpad.net/YourAccount/CreatingAnSSHKeyPair    
       
3. `Upload your SSH public key to Launchpad`_.
 
.. _Upload your SSH public key to Launchpad: https://launchpad.net/~/+editsshkeys
    
4. `Make a team for your project`_.  Even if you're starting as the only
   developer on this project, creating a new one now will let you more
   easily add other people later.
 
.. _Make a team for your project: https://help.launchpad.net/Teams/CreatingAndRunning
      
5. `Create a project`_.
  
.. _Create a project: https://help.launchpad.net/Projects/Registering

6. Tell Bazaar your Launchpad account name.  If your account is john.doe, type ::
  
      $ bzr launchpad-login john.doe

7. `Push the branch for your project`_.  Once you've committed your changes 
   locally, you can publish them as the trunk of your new project by saying
    
       $ bzr push lp:~sample-developers/sample/trunk
       
   (Of course, using the team and project names you just chose.)
 
.. _Push the branch for your project: https://help.launchpad.net/Code/UploadingABranch

Creating your own copy of another branch
========================================

To work with someone else's code, you can make your own copy of their
branch. Let's take a real-world example, Bazaar's GTK interface::

  $ bzr init-repo ~/bzr-gtk
  $ bzr branch lp:~bzr/bzr-gtk/trunk ~/bzr-gtk/john
  Branched 292 revision(s).

Bazaar will download all the files and complete revision history from the
bzr-gtk project's trunk branch and create a copy called ``john``.

Now, you have your own copy of the branch and can commit changes with
or without a net connection. You can share your branch at any time by
publishing it and, if the  bzr-gtk team want to use your work, Bazaar
makes it easy for them to merge your branch back into their trunk branch.


Updating your branch from the main branch
=========================================

While you commit changes to your branch, it's likely that other people will
also continue to commit code to the parent branch.

To make sure your branch stays up to date, you should merge changes from
the parent into your personal branch::

  $ bzr merge
  Merging from saved parent location: http://bazaar.launchpad.net/~bzr/bzr-gtk/trunk
  All changes applied successfully.

Check what has changed::

  $ bzr diff

If different branches have made changes to the same areas of the same
files, then merging them may generate conflicts.  When this happens,
Bazaar puts text markers like ``<<<<<<<`` into the files, and records them
in a list of conflicted files.  You should edit the files to reflect the
way you want to resolve the conflicts, use ``bzr diff`` to check the
changes, and then ``bzr resolve`` to mark them as resolved.

If you're happy with the changes, you can commit them to your personal
branch::

  $ bzr commit -m "Merge from main branch"
  Committed revision 295.


Learning more
=============

You can find out more about Bazaar in the
`Bazaar User Guide <../user-guide/index.html>`_.

To learn about Bazaar on the command-line::

  $ bzr help

To learn about the ''foo'' topic or command::

  $ bzr help foo

Licence
=======

Copyright 2007-2011 Canonical Ltd. Bazaar is free software, and you
may use, modify and redistribute both Bazaar and this document under
the terms of the GNU General Public License version 2 or later. See
<http://www.gnu.org/licenses/>.
