git/Documentation/git-diff.txt
Denton Liu eb448631fb git-diff: fix missing --merge-base docs
When `git diff --merge-base` was introduced at around Git 2.30, the
documentation included a few errors.

In the example given for `git diff --cached --merge-base`, the
`--cached` flag was omitted for the `--merge-base` example. Add the
missing flag.

In the `git diff <commit>` case, we failed to mention that
`--merge-base` is an available option. Give the usage of `--merge-base`
as an option there.

Finally, there are two errors in the usage of `git diff`. Firstly, we do
not mention `--merge-base` in the `git diff --cached` case. Mention it
so that it's consistent with the documentation. Secondly, we put the
`[--merge-base]` in between `<commit>` and `[<commit>...]`. Move the
`[--merge-base]` so that it's beside `[<options>]` which is a more
logical grouping.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-12 13:55:29 -07:00

229 lines
7.3 KiB
Plaintext

git-diff(1)
===========
NAME
----
git-diff - Show changes between commits, commit and working tree, etc
SYNOPSIS
--------
[verse]
'git diff' [<options>] [<commit>] [--] [<path>...]
'git diff' [<options>] --cached [--merge-base] [<commit>] [--] [<path>...]
'git diff' [<options>] [--merge-base] <commit> [<commit>...] <commit> [--] [<path>...]
'git diff' [<options>] <commit>...<commit> [--] [<path>...]
'git diff' [<options>] <blob> <blob>
'git diff' [<options>] --no-index [--] <path> <path>
DESCRIPTION
-----------
Show changes between the working tree and the index or a tree, changes
between the index and a tree, changes between two trees, changes resulting
from a merge, changes between two blob objects, or changes between two
files on disk.
'git diff' [<options>] [--] [<path>...]::
This form is to view the changes you made relative to
the index (staging area for the next commit). In other
words, the differences are what you _could_ tell Git to
further add to the index but you still haven't. You can
stage these changes by using linkgit:git-add[1].
'git diff' [<options>] --no-index [--] <path> <path>::
This form is to compare the given two paths on the
filesystem. You can omit the `--no-index` option when
running the command in a working tree controlled by Git and
at least one of the paths points outside the working tree,
or when running the command outside a working tree
controlled by Git. This form implies `--exit-code`.
'git diff' [<options>] --cached [--merge-base] [<commit>] [--] [<path>...]::
This form is to view the changes you staged for the next
commit relative to the named <commit>. Typically you
would want comparison with the latest commit, so if you
do not give <commit>, it defaults to HEAD.
If HEAD does not exist (e.g. unborn branches) and
<commit> is not given, it shows all staged changes.
--staged is a synonym of --cached.
+
If --merge-base is given, instead of using <commit>, use the merge base
of <commit> and HEAD. `git diff --cached --merge-base A` is equivalent to
`git diff --cached $(git merge-base A HEAD)`.
'git diff' [<options>] [--merge-base] <commit> [--] [<path>...]::
This form is to view the changes you have in your
working tree relative to the named <commit>. You can
use HEAD to compare it with the latest commit, or a
branch name to compare with the tip of a different
branch.
+
If --merge-base is given, instead of using <commit>, use the merge base
of <commit> and HEAD. `git diff --merge-base A` is equivalent to
`git diff $(git merge-base A HEAD)`.
'git diff' [<options>] [--merge-base] <commit> <commit> [--] [<path>...]::
This is to view the changes between two arbitrary
<commit>.
+
If --merge-base is given, use the merge base of the two commits for the
"before" side. `git diff --merge-base A B` is equivalent to
`git diff $(git merge-base A B) B`.
'git diff' [<options>] <commit> <commit>... <commit> [--] [<path>...]::
This form is to view the results of a merge commit. The first
listed <commit> must be the merge itself; the remaining two or
more commits should be its parents. A convenient way to produce
the desired set of revisions is to use the `^@` suffix.
For instance, if `master` names a merge commit, `git diff master
master^@` gives the same combined diff as `git show master`.
'git diff' [<options>] <commit>..<commit> [--] [<path>...]::
This is synonymous to the earlier form (without the `..`) for
viewing the changes between two arbitrary <commit>. If <commit> on
one side is omitted, it will have the same effect as
using HEAD instead.
'git diff' [<options>] <commit>\...<commit> [--] [<path>...]::
This form is to view the changes on the branch containing
and up to the second <commit>, starting at a common ancestor
of both <commit>. `git diff A...B` is equivalent to
`git diff $(git merge-base A B) B`. You can omit any one
of <commit>, which has the same effect as using HEAD instead.
Just in case you are doing something exotic, it should be
noted that all of the <commit> in the above description, except
in the `--merge-base` case and in the last two forms that use `..`
notations, can be any <tree>.
For a more complete list of ways to spell <commit>, see
"SPECIFYING REVISIONS" section in linkgit:gitrevisions[7].
However, "diff" is about comparing two _endpoints_, not ranges,
and the range notations (`<commit>..<commit>` and
`<commit>...<commit>`) do not mean a range as defined in the
"SPECIFYING RANGES" section in linkgit:gitrevisions[7].
'git diff' [<options>] <blob> <blob>::
This form is to view the differences between the raw
contents of two blob objects.
OPTIONS
-------
:git-diff: 1
include::diff-options.txt[]
-1 --base::
-2 --ours::
-3 --theirs::
Compare the working tree with the "base" version (stage #1),
"our branch" (stage #2) or "their branch" (stage #3). The
index contains these stages only for unmerged entries i.e.
while resolving conflicts. See linkgit:git-read-tree[1]
section "3-Way Merge" for detailed information.
-0::
Omit diff output for unmerged entries and just show
"Unmerged". Can be used only when comparing the working tree
with the index.
<path>...::
The <paths> parameters, when given, are used to limit
the diff to the named paths (you can give directory
names and get diff for all files under them).
include::diff-format.txt[]
EXAMPLES
--------
Various ways to check your working tree::
+
------------
$ git diff <1>
$ git diff --cached <2>
$ git diff HEAD <3>
------------
+
<1> Changes in the working tree not yet staged for the next commit.
<2> Changes between the index and your last commit; what you
would be committing if you run `git commit` without `-a` option.
<3> Changes in the working tree since your last commit; what you
would be committing if you run `git commit -a`
Comparing with arbitrary commits::
+
------------
$ git diff test <1>
$ git diff HEAD -- ./test <2>
$ git diff HEAD^ HEAD <3>
------------
+
<1> Instead of using the tip of the current branch, compare with the
tip of "test" branch.
<2> Instead of comparing with the tip of "test" branch, compare with
the tip of the current branch, but limit the comparison to the
file "test".
<3> Compare the version before the last commit and the last commit.
Comparing branches::
+
------------
$ git diff topic master <1>
$ git diff topic..master <2>
$ git diff topic...master <3>
------------
+
<1> Changes between the tips of the topic and the master branches.
<2> Same as above.
<3> Changes that occurred on the master branch since when the topic
branch was started off it.
Limiting the diff output::
+
------------
$ git diff --diff-filter=MRC <1>
$ git diff --name-status <2>
$ git diff arch/i386 include/asm-i386 <3>
------------
+
<1> Show only modification, rename, and copy, but not addition
or deletion.
<2> Show only names and the nature of change, but not actual
diff output.
<3> Limit diff output to named subtrees.
Munging the diff output::
+
------------
$ git diff --find-copies-harder -B -C <1>
$ git diff -R <2>
------------
+
<1> Spend extra cycles to find renames, copies and complete
rewrites (very expensive).
<2> Output diff in reverse.
SEE ALSO
--------
diff(1),
linkgit:git-difftool[1],
linkgit:git-log[1],
linkgit:gitdiffcore[7],
linkgit:git-format-patch[1],
linkgit:git-apply[1],
linkgit:git-show[1]
GIT
---
Part of the linkgit:git[1] suite