Specifying revisions
====================

Revision identifiers and ranges
-------------------------------

Bazaar has a very expressive way to specify a revision or a range of revisions.
To specify a range of revisions, the upper and lower bounds are separated by the
``..`` symbol. For example::

    $ bzr log -r 1..4

You can omit one bound like::

    $ bzr log -r 1..
    $ bzr log -r ..4

Some commands take only one revision, not a range. For example::

    $ bzr cat -r 42 foo.c

In other cases, a range is required but you want the length of the range to
be one. For commands where this is relevant, the ``-c`` option is used like this::

    $ bzr diff -c 42


Available revision identifiers
------------------------------

The revision, or the bounds of the range, can be given using
different format specifications as shown below.

 +----------------------+------------------------------------+
 |  argument type       | description                        |
 +----------------------+------------------------------------+
 | *number*             | revision number                    |
 +----------------------+------------------------------------+
 | **revno**:*number*   | positive revision number           |
 +----------------------+------------------------------------+
 | **last**:*number*    | negative revision number           |
 +----------------------+------------------------------------+
 | **revid**:*guid*     | globally unique revision id        |
 +----------------------+------------------------------------+
 | **before**:*rev*     | leftmost parent of ''rev''         |
 +----------------------+------------------------------------+
 | **date**:*value*     | first entry after a given date     |
 +----------------------+------------------------------------+
 | **tag**:*value*      | revision matching a given tag      |
 +----------------------+------------------------------------+
 | **ancestor**:*path*  | last merged revision from a branch |
 +----------------------+------------------------------------+
 | **branch**:*path*    | latest revision on another branch  |
 +----------------------+------------------------------------+
 | **submit**:*path*    | common ancestor with submit branch |
 +----------------------+------------------------------------+

A brief introduction to some of these formats is given below.
For complete details, see `Revision Identifiers`_ in the
Bazaar User Reference.

.. _Revision Identifiers: ../user-reference/bzr_man.html#revision-identifiers

Numbers
~~~~~~~

Positive numbers denote revision numbers in the current branch. Revision
numbers are labelled as "revno" in the output of ``bzr log``.  To display
the log for the first ten revisions::

    $ bzr log -r ..10

Negative numbers count from the latest revision, -1 is the last committed
revision.

To display the log for the last ten revisions::

    $ bzr log -r -10..

revid
~~~~~

**revid** allows specifying a an internal revision ID, as shown by ``bzr
log`` and some other commands.

For example::

    $ bzr log -r revid:Matthieu.Moy@imag.fr-20051026185030-93c7cad63ee570df

before
~~~~~~

**before**
    ''rev'' specifies the leftmost parent of ''rev'', that is the revision
    that appears before ''rev'' in the revision history, or the revision that
    was current when ''rev'' what comitted.

''rev'' can be any revision specifier and may be chained.

For example::

    $ bzr log -r before:before:4
    ...
    revno: 2
    ...

date
~~~~

**date**
    ''value'' matches the first history entry after a given date, either at
    midnight or at a specified time.

Legal values are:

 * **yesterday**
 * **today**
 * **tomorrow**
 * A **YYYY-MM-DD** format date.
 * A **YYYY-MM-DD,HH:MM:SS** format date/time, seconds are optional (note the
   comma)

The proper way of saying "give me all the log entries for today" is::

    $ bzr log -r date:yesterday..date:today

Ancestor
~~~~~~~~

**ancestor**:*path*
    specifies the common ancestor between the current branch and a 
    different branch. This is the same ancestor that would be used for
    merging purposes.

*path* may be the URL of a remote branch, or the file path to a local branch.

For example, to see what changes were made on a branch since it was forked
off ``../parent``::

    $ bzr diff -r ancestor:../parent

Branch
~~~~~~

branch
   ``path`` specifies the latest revision in another branch.

``path`` may be the URL of a remote branch, or the file path to a local branch.

For example, to get the differences between this and another branch::

    $ bzr diff -r branch:http://example.com/bzr/foo.dev

