xdiff/xdiffi.c: fix warnings about possibly uninitialized variables

[thirdparty/git.git] / Documentation / git-diff-tree.txt

git-diff-tree(1)
================

NAME
----
git-diff-tree - Compares the content and mode of blobs found via two tree objects


SYNOPSIS
--------
[verse]
'git-diff-tree' [--stdin] [-m] [-s] [-v] [--no-commit-id] [--pretty]
	      [-t] [-r] [-c | --cc] [--root] [<common diff options>]
	      <tree-ish> [<tree-ish>] [<path>...]

DESCRIPTION
-----------
Compares the content and mode of the blobs found via two tree objects.

If there is only one <tree-ish> given, the commit is compared with its parents
(see --stdin below).

Note that "git-diff-tree" can use the tree encapsulated in a commit object.

OPTIONS
-------
include::diff-options.txt[]

<tree-ish>::
	The id of a tree object.

<path>...::
	If provided, the results are limited to a subset of files
	matching one of these prefix strings.
	ie file matches `/^<pattern1>|<pattern2>|.../`
	Note that this parameter does not provide any wildcard or regexp
	features.

-r::
        recurse into sub-trees

-t::
	show tree entry itself as well as subtrees.  Implies -r.

--root::
	When '--root' is specified the initial commit will be showed as a big
	creation event. This is equivalent to a diff against the NULL tree.

--stdin::
	When '--stdin' is specified, the command does not take
	<tree-ish> arguments from the command line.  Instead, it
	reads either one <commit> or a pair of <tree-ish>
	separated with a single space from its standard input.
+
When a single commit is given on one line of such input, it compares
the commit with its parents.  The following flags further affects its
behaviour.  This does not apply to the case where two <tree-ish>
separated with a single space are given.

-m::
	By default, "git-diff-tree --stdin" does not show
	differences for merge commits.  With this flag, it shows
	differences to that commit from all of its parents.

-s::
	By default, "git-diff-tree --stdin" shows differences,
	either in machine-readable form (without '-p') or in patch
	form (with '-p').  This output can be suppressed.  It is
	only useful with '-v' flag.

-v::
	This flag causes "git-diff-tree --stdin" to also show
	the commit message before the differences.

--pretty[=(raw|medium|short)]::
	This is used to control "pretty printing" format of the
	commit message.  Without "=<style>", it defaults to
	medium.

--no-commit-id::
	git-diff-tree outputs a line with the commit ID when
	applicable.  This flag suppressed the commit ID output.

-c,--cc::
	These flags change the way a merge commit is displayed
	(which means it is useful only when the command is given
	one <tree-ish>, or '--stdin').  It shows the differences
	from each of the parents to the merge result
	simultaneously, instead of showing pairwise diff between
	a parent and the result one at a time, which '-m' option
	output does.  '--cc' further compresses the output by
	omiting hunks that show differences from only one
	parent, or show the same change from all but one parent
	for an Octopus merge.  When this optimization makes all
	hunks disappear, the commit itself and the commit log
	message is not shown, just like any other "empty diff" cases.

--always::
	Show the commit itself and the commit log message even
	if the diff itself is empty.


Limiting Output
---------------
If you're only interested in differences in a subset of files, for
example some architecture-specific files, you might do:

	git-diff-tree -r <tree-ish> <tree-ish> arch/ia64 include/asm-ia64

and it will only show you what changed in those two directories.

Or if you are searching for what changed in just `kernel/sched.c`, just do

	git-diff-tree -r <tree-ish> <tree-ish> kernel/sched.c

and it will ignore all differences to other files.

The pattern is always the prefix, and is matched exactly.  There are no
wildcards.  Even stricter, it has to match a complete path component.
I.e. "foo" does not pick up `foobar.h`.  "foo" does match `foo/bar.h`
so it can be used to name subdirectories.

An example of normal usage is:

  torvalds@ppc970:~/git> git-diff-tree 5319e4......
  *100664->100664 blob    ac348b.......->a01513.......      git-fsck-objects.c

which tells you that the last commit changed just one file (it's from
this one:

-----------------------------------------------------------------------------
commit 3c6f7ca19ad4043e9e72fa94106f352897e651a8
tree 5319e4d609cdd282069cc4dce33c1db559539b03
parent b4e628ea30d5ab3606119d2ea5caeab141d38df7
author Linus Torvalds <torvalds@ppc970.osdl.org> Sat Apr 9 12:02:30 2005
committer Linus Torvalds <torvalds@ppc970.osdl.org> Sat Apr 9 12:02:30 2005

Make "git-fsck-objects" print out all the root commits it finds.

Once I do the reference tracking, I'll also make it print out all the
HEAD commits it finds, which is even more interesting.
-----------------------------------------------------------------------------

in case you care).

Output format
-------------
include::diff-format.txt[]


Author
------
Written by Linus Torvalds <torvalds@osdl.org>

Documentation
--------------
Documentation by David Greaves, Junio C Hamano and the git-list <git@vger.kernel.org>.

GIT
---
Part of the gitlink:git[7] suite