NAME
git-diff - Show changes between commits, commit and working tree, etc
SYNOPSIS
git diff [<common diff options>] <commit>{0,2} [--] [<path>...]
DESCRIPTION
Show changes between two trees, a tree and the working tree, a tree and
the index file, or the index file and the working tree.
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 git-add(1).
If exactly two paths are given, and at least one is untracked,
compare the two files / directories. This behavior can be forced by
--no-index.
git diff [--options] --cached [<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. --staged is a synonym of --cached.
git diff [--options] <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.
git diff [--options] <commit> <commit> [--] [<path>...]
This is to view the changes between two arbitrary <commit>.
git diff [--options] <commit>..<commit> [--] [<path>...]
This is synonymous to the previous form. 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 if you are doing something exotic, it should be noted that
all of the <commit> in the above description, except for the last two
forms that use ".." notations, can be any <tree-ish>.
For a more complete list of ways to spell <commit>, see "SPECIFYING
REVISIONS" section in git-rev-parse(1). 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 git-rev-parse(1).
OPTIONS
-p, -u
Generate patch (see section on generating patches). This is the
default.
-U<n>, --unified=<n>
Generate diffs with <n> lines of context instead of the usual
three. Implies -p.
--raw
Generate the raw format.
--patch-with-raw
Synonym for -p --raw.
--patience
Generate a diff using the "patience diff" algorithm.
--stat[=width[,name-width]]
Generate a diffstat. You can override the default output width for
80-column terminal by --stat=width. The width of the filename part
can be controlled by giving another width to it separated by a
comma.
--numstat
Similar to --stat, but shows number of added and deleted lines in
decimal notation and pathname without abbreviation, to make it more
machine friendly. For binary files, outputs two - instead of saying
0 0.
--shortstat
Output only the last line of the --stat format containing total
number of modified files, as well as number of added and deleted
lines.
--dirstat[=limit]
Output the distribution of relative amount of changes (number of
lines added or removed) for each sub-directory. Directories with
changes below a cut-off percent (3% by default) are not shown. The
cut-off percent can be set with --dirstat=limit. Changes in a child
directory is not counted for the parent directory, unless
--cumulative is used.
--dirstat-by-file[=limit]
Same as --dirstat, but counts changed files instead of lines.
--summary
Output a condensed summary of extended header information such as
creations, renames and mode changes.
--patch-with-stat
Synonym for -p --stat.
-z
When --raw, --numstat, --name-only or --name-status has been given,
do not munge pathnames and use NULs as output field terminators.
Without this option, each pathname output will have TAB, LF, double
quotes, and backslash characters replaced with \t, \n, \", and \\,
respectively, and the pathname will be enclosed in double quotes if
any of those replacements occurred.
--name-only
Show only names of changed files.
--name-status
Show only names and status of changed files. See the description of
the --diff-filter option on what the status letters mean.
--submodule[=<format>]
Chose the output format for submodule differences. <format> can be
one of short and log. short just shows pairs of commit names, this
format is used when this option is not given. log is the default
value for this option and lists the commits in that commit range
like the summary option of git-submodule(1) does.
--color[=<when>]
Show colored diff. The value must be always (the default), never,
or auto.
--no-color
Turn off colored diff, even when the configuration file gives the
default to color output. Same as --color=never.
--color-words[=<regex>]
Show colored word diff, i.e., color words which have changed. By
default, words are separated by whitespace.
When a <regex> is specified, every non-overlapping match of the
<regex> is considered a word. Anything between these matches is
considered whitespace and ignored(!) for the purposes of finding
differences. You may want to append |[^[:space:]] to your regular
expression to make sure that it matches all non-whitespace
characters. A match that contains a newline is silently
truncated(!) at the newline.
The regex can also be set via a diff driver or configuration
option, see gitattributes(1) or git-config(1). Giving it explicitly
overrides any diff driver or configuration setting. Diff drivers
override configuration settings.
--no-renames
Turn off rename detection, even when the configuration file gives
the default to do so.
--check
Warn if changes introduce trailing whitespace or an indent that
uses a space before a tab. Exits with non-zero status if problems
are found. Not compatible with --exit-code.
--full-index
Instead of the first handful of characters, show the full pre- and
post-image blob object names on the "index" line when generating
patch format output.
--binary
In addition to --full-index, output a binary diff that can be
applied with git-apply.
--abbrev[=<n>]
Instead of showing the full 40-byte hexadecimal object name in
diff-raw format output and diff-tree header lines, show only a
partial prefix. This is independent of the --full-index option
above, which controls the diff-patch output format. Non default
number of digits can be specified with --abbrev=<n>.
-B
Break complete rewrite changes into pairs of delete and create.
-M
Detect renames.
-C
Detect copies as well as renames. See also --find-copies-harder.
--diff-filter=[ACDMRTUXB*]
Select only files that are Added (A), Copied (C), Deleted (D),
Modified (M), Renamed (R), have their type (i.e. regular file,
symlink, submodule, ...) changed (T), are Unmerged (U), are Unknown
(X), or have had their pairing Broken (B). Any combination of the
filter characters may be used. When * (All-or-none) is added to the
combination, all paths are selected if there is any file that
matches other criteria in the comparison; if there is no file that
matches other criteria, nothing is selected.
--find-copies-harder
For performance reasons, by default, -C option finds copies only if
the original file of the copy was modified in the same changeset.
This flag makes the command inspect unmodified files as candidates
for the source of copy. This is a very expensive operation for
large projects, so use it with caution. Giving more than one -C
option has the same effect.
-l<num>
The -M and -C options require O(n^2) processing time where n is the
number of potential rename/copy targets. This option prevents
rename/copy detection from running if the number of rename/copy
targets exceeds the specified number.
-S<string>
Look for differences that introduce or remove an instance of
<string>. Note that this is different than the string simply
appearing in diff output; see the pickaxe entry in gitdiffcore(7)
for more details.
--pickaxe-all
When -S finds a change, show all the changes in that changeset, not
just the files that contain the change in <string>.
--pickaxe-regex
Make the <string> not a plain string but an extended POSIX regex to
match.
-O<orderfile>
Output the patch in the order specified in the <orderfile>, which
has one shell glob pattern per line.
-R
Swap two inputs; that is, show differences from index or on-disk
file to tree contents.
--relative[=<path>]
When run from a subdirectory of the project, it can be told to
exclude changes outside the directory and show pathnames relative
to it with this option. When you are not in a subdirectory (e.g. in
a bare repository), you can name which subdirectory to make the
output relative to by giving a <path> as an argument.
-a, --text
Treat all files as text.
--ignore-space-at-eol
Ignore changes in whitespace at EOL.
-b, --ignore-space-change
Ignore changes in amount of whitespace. This ignores whitespace at
line end, and considers all other sequences of one or more
whitespace characters to be equivalent.
-w, --ignore-all-space
Ignore whitespace when comparing lines. This ignores differences
even if one line has whitespace where the other line has none.
--inter-hunk-context=<lines>
Show the context between diff hunks, up to the specified number of
lines, thereby fusing hunks that are close to each other.
--exit-code
Make the program exit with codes similar to diff(1). That is, it
exits with 1 if there were differences and 0 means no differences.
--quiet
Disable all output of the program. Implies --exit-code.
--ext-diff
Allow an external diff helper to be executed. If you set an
external diff driver with gitattributes(5), you need to use this
option with git-log(1) and friends.
--no-ext-diff
Disallow external diff drivers.
--ignore-submodules
Ignore changes to submodules in the diff generation.
--src-prefix=<prefix>
Show the given source prefix instead of "a/".
--dst-prefix=<prefix>
Show the given destination prefix instead of "b/".
--no-prefix
Do not show any source or destination prefix.
For more detailed explanation on these common options, see also
gitdiffcore(7).
<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).
RAW OUTPUT FORMAT
The raw output format from "git-diff-index", "git-diff-tree",
"git-diff-files" and "git diff --raw" are very similar.
These commands all compare two sets of things; what is compared
differs:
git-diff-index <tree-ish>
compares the <tree-ish> and the files on the filesystem.
git-diff-index --cached <tree-ish>
compares the <tree-ish> and the index.
git-diff-tree [-r] <tree-ish-1> <tree-ish-2> [<pattern>...]
compares the trees named by the two arguments.
git-diff-files [<pattern>...]
compares the index and the files on the filesystem.
The "git-diff-tree" command begins its output by printing the hash of
what is being compared. After that, all the commands print one output
line per changed file.
An output line is formatted this way:
in-place edit :100644 100644 bcd1234... 0123456... M file0
copy-edit :100644 100644 abcd123... 1234567... C68 file1 file2
rename-edit :100644 100644 abcd123... 1234567... R86 file1 file3
create :000000 100644 0000000... 1234567... A file4
delete :100644 000000 1234567... 0000000... D file5
unmerged :000000 000000 0000000... 0000000... U file6
That is, from the left to the right:
1. a colon.
2. mode for "src"; 000000 if creation or unmerged.
3. a space.
4. mode for "dst"; 000000 if deletion or unmerged.
5. a space.
6. sha1 for "src"; 0{40} if creation or unmerged.
7. a space.
8. sha1 for "dst"; 0{40} if creation, unmerged or "look at work tree".
9. a space.
10. status, followed by optional "score" number.
11. a tab or a NUL when -z option is used.
12. path for "src"
13. a tab or a NUL when -z option is used; only exists for C or R.
14. path for "dst"; only exists for C or R.
15. an LF or a NUL when -z option is used, to terminate the record.
Possible status letters are:
o A: addition of a file
o C: copy of a file into a new one
o D: deletion of a file
o M: modification of the contents or mode of a file
o R: renaming of a file
o T: change in the type of the file
o U: file is unmerged (you must complete the merge before it can be
committed)
o X: "unknown" change type (most probably a bug, please report it)
Status letters C and R are always followed by a score (denoting the
percentage of similarity between the source and target of the move or
copy), and are the only ones to be so.
<sha1> is shown as all 0's if a file is new on the filesystem and it is
out of sync with the index.
Example:
:100644 100644 5be4a4...... 000000...... M file.c
When -z option is not used, TAB, LF, and backslash characters in
pathnames are represented as \t, \n, and \\, respectively.
DIFF FORMAT FOR MERGES
"git-diff-tree", "git-diff-files" and "git-diff --raw" can take -c or
--cc option to generate diff output also for merge commits. The output
differs from the format described above in the following way:
1. there is a colon for each parent
2. there are more "src" modes and "src" sha1
3. status is concatenated status characters for each parent
4. no optional "score" number
5. single path, only for "dst"
Example:
::100644 100644 100644 fabadb8... cc95eb0... 4866510... MM describe.c
Note that combined diff lists only files which were modified from all
parents.
GENERATING PATCHES WITH -P
When "git-diff-index", "git-diff-tree", or "git-diff-files" are run
with a -p option, "git diff" without the --raw option, or "git log"
with the "-p" option, they do not produce the output described above;
instead they produce a patch file. You can customize the creation of
such patches via the GIT_EXTERNAL_DIFF and the GIT_DIFF_OPTS
environment variables.
What the -p option produces is slightly different from the traditional
diff format.
1. It is preceded with a "git diff" header, that looks like this:
diff --git a/file1 b/file2
The a/ and b/ filenames are the same unless rename/copy is
involved. Especially, even for a creation or a deletion, /dev/null
is not used in place of a/ or b/ filenames.
When rename/copy is involved, file1 and file2 show the name of the
source file of the rename/copy and the name of the file that
rename/copy produces, respectively.
2. It is followed by one or more extended header lines:
old mode <mode>
new mode <mode>
deleted file mode <mode>
new file mode <mode>
copy from <path>
copy to <path>
rename from <path>
rename to <path>
similarity index <number>
dissimilarity index <number>
index <hash>..<hash> <mode>
3. TAB, LF, double quote and backslash characters in pathnames are
represented as \t, \n, \" and \\, respectively. If there is need
for such substitution then the whole pathname is put in double
quotes.
The similarity index is the percentage of unchanged lines, and the
dissimilarity index is the percentage of changed lines. It is a rounded
down integer, followed by a percent sign. The similarity index value of
100% is thus reserved for two equal files, while 100% dissimilarity
means that no line from the old file made it into the new one.
COMBINED DIFF FORMAT
"git-diff-tree", "git-diff-files" and "git-diff" can take -c or --cc
option to produce combined diff. For showing a merge commit with "git
log -p", this is the default format; you can force showing full diff
with the -m option. A combined diff format looks like this:
diff --combined describe.c
index fabadb8,cc95eb0..4866510
--- a/describe.c
+++ b/describe.c
@@@ -98,20 -98,12 +98,20 @@@
return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1;
}
- static void describe(char *arg)
-static void describe(struct commit *cmit, int last_one)
++static void describe(char *arg, int last_one)
{
+ unsigned char sha1[20];
+ struct commit *cmit;
struct commit_list *list;
static int initialized = 0;
struct commit_name *n;
+ if (get_sha1(arg, sha1) < 0)
+ usage(describe_usage);
+ cmit = lookup_commit_reference(sha1);
+ if (!cmit)
+ usage(describe_usage);
+
if (!initialized) {
initialized = 1;
for_each_ref(get_name);
1. It is preceded with a "git diff" header, that looks like this (when
-c option is used):
diff --combined file
or like this (when --cc option is used):
diff --cc file
2. It is followed by one or more extended header lines (this example
shows a merge with two parents):
index <hash>,<hash>..<hash>
mode <mode>,<mode>..<mode>
new file mode <mode>
deleted file mode <mode>,<mode>
The mode <mode>,<mode>..<mode> line appears only if at least one of
the <mode> is different from the rest. Extended headers with
information about detected contents movement (renames and copying
detection) are designed to work with diff of two <tree-ish> and are
not used by combined diff format.
3. It is followed by two-line from-file/to-file header
--- a/file
+++ b/file
Similar to two-line header for traditional unified diff format,
/dev/null is used to signal created or deleted files.
4. Chunk header format is modified to prevent people from accidentally
feeding it to patch -p1. Combined diff format was created for
review of merge commit changes, and was not meant for apply. The
change is similar to the change in the extended index header:
@@@ <from-file-range> <from-file-range> <to-file-range> @@@
There are (number of parents + 1) @ characters in the chunk header
for combined diff format.
Unlike the traditional unified diff format, which shows two files A and
B with a single column that has - (minus -- appears in A but removed in
B), + (plus -- missing in A but added to B), or " " (space --
unchanged) prefix, this format compares two or more files file1,
file2,... with one file X, and shows how X differs from each of fileN.
One column for each of fileN is prepended to the output line to note
how X's line is different from it.
A - character in the column N means that the line appears in fileN but
it does not appear in the result. A + character in the column N means
that the line appears in the result, and fileN does not have that line
(in other words, the line was added, from the point of view of that
parent).
In the above example output, the function signature was changed from
both files (hence two - removals from both file1 and file2, plus ++ to
mean one line that was added does not appear in either file1 nor
file2). Also eight other lines are the same from file1 but do not
appear in file2 (hence prefixed with +).
When shown by git diff-tree -c, it compares the parents of a merge
commit with the merge result (i.e. file1..fileN are the parents). When
shown by git diff-files -c, it compares the two unresolved merge
parents with the working tree file (i.e. file1 is stage 2 aka "our
version", file2 is stage 3 aka "their version").
OTHER DIFF FORMATS
The --summary option describes newly added, deleted, renamed and copied
files. The --stat option adds diffstat(1) graph to the output. These
options can be combined with other options, such as -p, and are meant
for human consumption.
When showing a change that involves a rename or a copy, --stat output
formats the pathnames compactly by combining common prefix and suffix
of the pathnames. For example, a change that moves arch/i386/Makefile
to arch/x86/Makefile while modifying 4 lines will be shown like this:
arch/{i386 => x86}/Makefile | 4 +--
The --numstat option gives the diffstat(1) information but is designed
for easier machine consumption. An entry in --numstat output looks like
this:
1 2 README
3 1 arch/{i386 => x86}/Makefile
That is, from left to right:
1. the number of added lines;
2. a tab;
3. the number of deleted lines;
4. a tab;
5. pathname (possibly with rename/copy information);
6. a newline.
When -z output option is in effect, the output is formatted this way:
1 2 README NUL
3 1 NUL arch/i386/Makefile NUL arch/x86/Makefile NUL
That is:
1. the number of added lines;
2. a tab;
3. the number of deleted lines;
4. a tab;
5. a NUL (only exists if renamed/copied);
6. pathname in preimage;
7. a NUL (only exists if renamed/copied);
8. pathname in postimage (only exists if renamed/copied);
9. a NUL.
The extra NUL before the preimage path in renamed case is to allow
scripts that read the output to tell if the current record being read
is a single-path record or a rename/copy record without reading ahead.
After reading added and deleted lines, reading up to NUL would yield
the pathname, but if that is NUL, the record will show two paths.
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 nor
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
git-difftool(1)
Show changes using common diff tools
AUTHOR
Written by Linus Torvalds <torvalds@osdl.org[1]>
DOCUMENTATION
Documentation by Junio C Hamano and the git-list
<git@vger.kernel.org[2]>.
GIT
Part of the git(1) suite
NOTES
1. torvalds@osdl.org
mailto:torvalds@osdl.org
2. git@vger.kernel.org
mailto:git@vger.kernel.org