Branching a project
Branch URLs
Before someone else can get a copy of your work, you need to agree on a transfer technology. You may decide to make the top level directory of your branch a network share, an approach familiar to Windows users. Linux and OS X users might prefer access to be via SFTP, a secure protocol built-in to most SSH servers. Bazaar is very flexible in this regard with support for lots of protocols some of which are given below.
Prefix Description file:// Access using the standard filesystem (default) sftp:// Access using SFTP (most SSH servers provide SFTP). bzr:// Fast access using the Bazaar smart server. ftp:// Access using passive FTP. http:// Read-only access to branches exported by a web server.
As indicated above, branches are identified using URLs with the prefix indicating the transfer technology. If no prefix is given, normal filenames are assumed. For a complete list of supported protocols, see the urlspec online help topic or the URL Identifiers section of the Bazaar User Reference.
URLs are normally resolved relative to the root directory of the server, so ftp://example.com/repo/foo means the /repo/foo directory of that host. (We say ‘normally’ because some server software like Apache can be configured to remap URLs arbitrarily, in which case you’ll need to look at the server configuration to find out which URL corresponds to which directory.)
To address a path relative to your home directory on the server, use a tilde like so: sftp://example.com/~/public_html should map to public_html within your home directory.
The branch command
To get a branch based on an existing branch, use the branch command. The syntax is:
bzr branch URL [directory]
If a directory is not given, one is created based on the last part of the URL. Here are some examples showing a drive qualified path (M:/) and an sftp URL respectively:
bzr branch M:/cool-trunk bzr branch sftp://bill@mary-laptop/cool-repo/cool-trunk
This example shows explicitly giving the directory name to use for the new branch:
bzr branch /home/mary/cool-repo/cool-trunk cool
Time and space considerations
Depending on the size of the branch being transferred and the speed and latency of the network between your computer and the source branch, this initial transfer might take some time. Subsequent updates should be much faster as only the changes are transferred then.
Keep in mind that Bazaar is transferring the complete history of the branch, not just the latest snapshot. As a consequence, you can be off the network (or disconnected from the network share) after branch completes but you’ll still be able to log and diff the history of the branch as much as you want. Furthermore, these operations are quick as the history is stored locally.
Note that Bazaar uses smart compression technology to minimize the amount of disk space required to store version history. In many cases, the complete history of a project will take up less disk space than the working copy of the latest version.
As explained in later chapters, Bazaar also has support for lightweight checkouts of a branch, i.e. working trees with no local storage of history. Of course, disconnected usage is not available then but that’s a tradeoff you can decide to make if local disk space is really tight for you. Support for limited lookback into history - history horizons - is currently under development as well.
Viewing branch information
If you wish to see information about a branch including where it came from, use the info command. For example:
bzr info cool
If no branch is given, information on the current branch is displayed.