diff
====

:Purpose: Show differences in the working tree, between revisions or branches.
:Usage:   brz diff [FILE...]

:Options:
  -c ARG, --change=ARG  Select changes introduced by the specified revision.
                        See also "help revisionspec".
  --context=ARG         How many lines of context to show.
  --diff-options=ARG    Pass these options to the external diff program.
  -F ARG, --format=ARG  Diff format to use.
  -h, --help            Show help message.
  --new=ARG             Branch/tree to compare to.
  --old=ARG             Branch/tree to compare from.
  -p ARG, --prefix=ARG  Set prefixes added to old and new filenames, as two
                        values separated by a colon. (eg "old/:new/").
  -q, --quiet           Only display errors and warnings.
  -r ARG, --revision=ARG
                        See "help revisionspec" for details.
  --usage               Show usage message and options.
  --using=ARG           Use this command to compare files.
  -v, --verbose         Display more information.

:Description:
  If no arguments are given, all changes for the current tree are listed.
  If files are given, only the changes in those files are listed.
  Remote and multiple branches can be compared by using the --old and
  --new options. If not provided, the default for both is derived from
  the first argument, if any, or the current tree if no arguments are
  given.
  
  "brz diff -p1" is equivalent to "brz diff --prefix old/:new/", and
  produces patches suitable for "patch -p1".
  
  Note that when using the -r argument with a range of revisions, the
  differences are computed between the two specified revisions.  That
  is, the command does not show the changes introduced by the first
  revision in the range.  This differs from the interpretation of
  revision ranges used by "brz log" which includes the first revision
  in the range.

:Exit values:
    1 - changed
    2 - unrepresentable changes
    3 - error
    0 - no change

:Examples:
    Shows the difference in the working tree versus the last commit::

        brz diff

    Difference between the working tree and revision 1::

        brz diff -r1

    Difference between revision 3 and revision 1::

        brz diff -r1..3

    Difference between revision 3 and revision 1 for branch xxx::

        brz diff -r1..3 xxx

    The changes introduced by revision 2 (equivalent to -r1..2)::

        brz diff -c2

    To see the changes introduced by revision X::

        brz diff -cX

    Note that in the case of a merge, the -c option shows the changes
    compared to the left hand parent. To see the changes against
    another parent, use::

        brz diff -r<chosen_parent>..X

    The changes between the current revision and the previous revision
    (equivalent to -c-1 and -r-2..-1)

        brz diff -r-2..

    Show just the differences for file NEWS::

        brz diff NEWS

    Show the differences in working tree xxx for file NEWS::

        brz diff xxx/NEWS

    Show the differences from branch xxx to this working tree:

        brz diff --old xxx

    Show the differences between two branches for file NEWS::

        brz diff --old xxx --new yyy NEWS

    Same as 'brz diff' but prefix paths with old/ and new/::

        brz diff --prefix old/:new/

    Show the differences using a custom diff program with options::

        brz diff --using /usr/bin/diff --diff-options -wu

:Aliases:  di, dif
:See also: :doc:`status <status-help>`


