1GIT-DIFF-INDEX(1) Git Manual GIT-DIFF-INDEX(1)
2
6 git-diff-index - Compares content and mode of blobs between the index
7 and repository
8
10 git-diff-index [-m] [--cached] [<common diff options>] <tree-ish>
11 [<path>...]
12
14 Compares the content and mode of the blobs found via a tree object with
15 the content of the current index and, optionally ignoring the stat
16 state of the file on disk. When paths are specified, compares only
17 those named paths. Otherwise all entries in the index are compared.
18
20 -p
21 Generate patch (see section on generating patches)
22 -u
24 Synonym for "-p".
25 -U<n>
27 Shorthand for "--unified=<n>".
28 --unified=<n>
30 Generate diffs with <n> lines of context instead of the usual
31 three. Implies "-p".
32 --raw
34 Generate the raw format.
35 --patch-with-raw
37 Synonym for "-p --raw".
38 --stat[=width[,name-width]]
40 Generate a diffstat. You can override the default output width for
41 80-column terminal by "--stat=width". The width of the filename
42 part can be controlled by giving another width to it separated by a
43 comma.
44 --numstat
46 Similar to --stat, but shows number of added and deleted lines in
47 decimal notation and pathname without abbreviation, to make it more
48 machine friendly. For binary files, outputs two - instead of saying
49 0 0.
50 --shortstat
52 Output only the last line of the --stat format containing total
53 number of modified files, as well as number of added and deleted
54 lines.
55 --summary
57 Output a condensed summary of extended header information such as
58 creations, renames and mode changes.
59 --patch-with-stat
61 Synonym for "-p --stat".
62 -z
64 NUL-line termination on output. This affects the --raw output field
65 terminator. Also output from commands such as "git-log" will be
66 delimited with NUL between commits.
67 --name-only
69 Show only names of changed files.
70 --name-status
72 Show only names and status of changed files.
73 --color
75 Show colored diff.
76 --no-color
78 Turn off colored diff, even when the configuration file gives the
79 default to color output.
80 --color-words
82 Show colored word diff, i.e. color words which have changed.
83 --no-renames
85 Turn off rename detection, even when the configuration file gives
86 the default to do so.
87 --check
89 Warn if changes introduce trailing whitespace or an indent that
90 uses a space before a tab.
91 --full-index
93 Instead of the first handful characters, show full object name of
94 pre- and post-image blob on the "index" line when generating a
95 patch format output.
96 --binary
98 In addition to --full-index, output "binary diff" that can be
99 applied with "git apply".
100 --abbrev[=<n>]
102 Instead of showing the full 40-byte hexadecimal object name in
103 diff-raw format output and diff-tree header lines, show only
104 handful hexdigits prefix. This is independent of --full-index
105 option above, which controls the diff-patch output format. Non
106 default number of digits can be specified with --abbrev=<n>.
107 -B
109 Break complete rewrite changes into pairs of delete and create.
110 -M
112 Detect renames.
113 -C
115 Detect copies as well as renames. See also --find-copies-harder.
116 --diff-filter=[ACDMRTUXB*]
118 Select only files that are Added (A), Copied (C), Deleted (D),
119 Modified (M), Renamed (R), have their type (mode) changed (T), are
120 Unmerged (U), are Unknown (X), or have had their pairing Broken
121 (B). Any combination of the filter characters may be used. When *
122 (All-or-none) is added to the combination, all paths are selected
123 if there is any file that matches other criteria in the comparison;
124 if there is no file that matches other criteria, nothing is
125 selected.
126 --find-copies-harder
128 For performance reasons, by default, -C option finds copies only if
129 the original file of the copy was modified in the same changeset.
130 This flag makes the command inspect unmodified files as candidates
131 for the source of copy. This is a very expensive operation for
132 large projects, so use it with caution. Giving more than one -C
133 option has the same effect.
134 -l<num>
136 -M and -C options require O(n^2) processing time where n is the
137 number of potential rename/copy targets. This option prevents
138 rename/copy detection from running if the number of rename/copy
139 targets exceeds the specified number.
140 -S<string>
142 Look for differences that contain the change in <string>.
143 --pickaxe-all
145 When -S finds a change, show all the changes in that changeset, not
146 just the files that contain the change in <string>.
147 --pickaxe-regex
149 Make the <string> not a plain string but an extended POSIX regex to
150 match.
151 -O<orderfile>
153 Output the patch in the order specified in the <orderfile>, which
154 has one shell glob pattern per line.
155 -R
157 Swap two inputs; that is, show differences from index or on-disk
158 file to tree contents.
159 --text
161 Treat all files as text.
162 -a
164 Shorthand for "--text".
165 --ignore-space-at-eol
167 Ignore changes in white spaces at EOL.
168 --ignore-space-change
170 Ignore changes in amount of white space. This ignores white space
171 at line end, and consider all other sequences of one or more white
172 space characters to be equivalent.
173 -b
175 Shorthand for "--ignore-space-change".
176 --ignore-all-space
178 Ignore white space when comparing lines. This ignores difference
179 even if one line has white space where the other line has none.
180 -w
182 Shorthand for "--ignore-all-space".
183 --exit-code
185 Make the program exit with codes similar to diff(1). That is, it
186 exits with 1 if there were differences and 0 means no differences.
187 --quiet
189 Disable all output of the program. Implies --exit-code.
190 --ext-diff
192 Allow an external diff helper to be executed. If you set an
193 external diff driver with gitlink:gitattributes(5), you need to use
194 this option with gitlink:git-log(1) and friends.
195 --no-ext-diff
197 Disallow external diff drivers.
198 For more detailed explanation on these common options, see also
199 diffcore documentation[1].
200 <tree-ish>
202 The id of a tree object to diff against.
203 --cached
205 do not consider the on-disk file at all
206 -m
208 By default, files recorded in the index but not checked out are
209 reported as deleted. This flag makes "git-diff-index" say that all
210 non-checked-out files are up to date.
211
213 The output format from "git-diff-index", "git-diff-tree" and
214 "git-diff-files" are very similar.
215 These commands all compare two sets of things; what is compared
217 differs:
218 git-diff-index <tree-ish>
220 compares the <tree-ish> and the files on the filesystem.
221 git-diff-index --cached <tree-ish>
223 compares the <tree-ish> and the index.
224 git-diff-tree [-r] <tree-ish-1> <tree-ish-2> [<pattern>...]
226 compares the trees named by the two arguments.
227 git-diff-files [<pattern>...]
229 compares the index and the files on the filesystem.
230 An output line is formatted this way:
231 in-place edit :100644 100644 bcd1234... 0123456... M file0
235 copy-edit :100644 100644 abcd123... 1234567... C68 file1 file2
236 rename-edit :100644 100644 abcd123... 1234567... R86 file1 file3
237 create :000000 100644 0000000... 1234567... A file4
238 delete :100644 000000 1234567... 0000000... D file5
239 unmerged :000000 000000 0000000... 0000000... U file6
240 That is, from the left to the right:
242 1. a colon.
245 2. mode for "src"; 000000 if creation or unmerged.
247 3. a space.
249 4. mode for "dst"; 000000 if deletion or unmerged.
251 5. a space.
253 6. sha1 for "src"; 0{40} if creation or unmerged.
255 7. a space.
257 8. sha1 for "dst"; 0{40} if creation, unmerged or "look at work
259 tree".
260 9. a space.
262 10. status, followed by optional "score" number.
264 11. a tab or a NUL when -z option is used.
266 12. path for "src"
268 13. a tab or a NUL when -z option is used; only exists for C or R.
270 14. path for "dst"; only exists for C or R.
272 15. an LF or a NUL when -z option is used, to terminate the record.
274 <sha1> is shown as all 0´s if a file is new on the filesystem and it is
275 out of sync with the index.
276 Example:
278 :100644 100644 5be4a4...... 000000...... M file.c
282 When -z option is not used, TAB, LF, and backslash characters in
284 pathnames are represented as \t, \n, and \\, respectively.
285
287 "git-diff-tree" and "git-diff-files" can take -c or --cc option to
288 generate diff output also for merge commits. The output differs from
289 the format described above in the following way:
290 1. there is a colon for each parent
293 2. there are more "src" modes and "src" sha1
295 3. status is concatenated status characters for each parent
297 4. no optional "score" number
299 5. single path, only for "dst"
301 Example:
302 ::100644 100644 100644 fabadb8... cc95eb0... 4866510... MM describe.c
306 Note that combined diff lists only files which were modified from all
308 parents.
309
311 When "git-diff-index", "git-diff-tree", or "git-diff-files" are run
312 with a -p option, they do not produce the output described above;
313 instead they produce a patch file. You can customize the creation of
314 such patches via the GIT_EXTERNAL_DIFF and the GIT_DIFF_OPTS
315 environment variables.
316 What the -p option produces is slightly different from the traditional
318 diff format.
319 1. It is preceded with a "git diff" header, that looks like this:
322 diff --git a/file1 b/file2
325 The a/ and b/ filenames are the same unless rename/copy is
326 involved. Especially, even for a creation or a deletion, /dev/null
327 is not used in place of a/ or b/ filenames.
328 When rename/copy is involved, file1 and file2 show the name of the
330 source file of the rename/copy and the name of the file that
331 rename/copy produces, respectively.
332 2. It is followed by one or more extended header lines:
334 old mode <mode>
337 new mode <mode>
338 deleted file mode <mode>
339 new file mode <mode>
340 copy from <path>
341 copy to <path>
342 rename from <path>
343 rename to <path>
344 similarity index <number>
345 dissimilarity index <number>
346 index <hash>..<hash> <mode>
347 3. TAB, LF, double quote and backslash characters in pathnames are
349 represented as \t, \n, \" and \\, respectively. If there is need
350 for such substitution then the whole pathname is put in double
351 quotes.
352 The similarity index is the percentage of unchanged lines, and the
353 dissimilarity index is the percentage of changed lines. It is a rounded
354 down integer, followed by a percent sign. The similarity index value of
355 100% is thus reserved for two equal files, while 100% dissimilarity
356 means that no line from the old file made it into the new one.
357
359 git-diff-tree and git-diff-files can take -c or --cc option to produce
360 combined diff, which looks like this:
361 diff --combined describe.c
365 index fabadb8,cc95eb0..4866510
366 --- a/describe.c
367 +++ b/describe.c
368 @@@ -98,20 -98,12 +98,20 @@@
369 return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1;
370 }
371 - static void describe(char *arg)
373 -static void describe(struct commit *cmit, int last_one)
374 ++static void describe(char *arg, int last_one)
375 {
376 + unsigned char sha1[20];
377 + struct commit *cmit;
378 struct commit_list *list;
379 static int initialized = 0;
380 struct commit_name *n;
381 + if (get_sha1(arg, sha1) < 0)
383 + usage(describe_usage);
384 + cmit = lookup_commit_reference(sha1);
385 + if (!cmit)
386 + usage(describe_usage);
387 +
388 if (!initialized) {
389 initialized = 1;
390 for_each_ref(get_name);
391 1. It is preceded with a "git diff" header, that looks like this
394 (when -c option is used):
395 diff --combined file
398 or like this (when --cc option is used):
399 diff --c file
402 2. It is followed by one or more extended header lines (this example
404 shows a merge with two parents):
405 index <hash>,<hash>..<hash>
408 mode <mode>,<mode>..<mode>
409 new file mode <mode>
410 deleted file mode <mode>,<mode>
411 The mode <mode>,<mode>..<mode> line appears only if at least one of
412 the <mode> is different from the rest. Extended headers with
413 information about detected contents movement (renames and copying
414 detection) are designed to work with diff of two <tree-ish> and are
415 not used by combined diff format.
416 3. It is followed by two-line from-file/to-file header
418 --- a/file
421 +++ b/file
422 Similar to two-line header for traditional unified diff format,
423 /dev/null is used to signal created or deleted files.
424 4. Chunk header format is modified to prevent people from
426 accidentally feeding it to patch -p1. Combined diff format was
427 created for review of merge commit changes, and was not meant for
428 apply. The change is similar to the change in the extended index
429 header:
430 @@@ <from-file-range> <from-file-range> <to-file-range> @@@
433 There are (number of parents + 1) @ characters in the chunk header
434 for combined diff format.
435 Unlike the traditional unified diff format, which shows two files A and
436 B with a single column that has - (minus — appears in A but removed in
437 B), + (plus — missing in A but added to B), or " " (space — unchanged)
438 prefix, this format compares two or more files file1, file2,... with
439 one file X, and shows how X differs from each of fileN. One column for
440 each of fileN is prepended to the output line to note how X´s line is
441 different from it.
442 A - character in the column N means that the line appears in fileN but
444 it does not appear in the result. A + character in the column N means
445 that the line appears in the last file, and fileN does not have that
446 line (in other words, the line was added, from the point of view of
447 that parent).
448 In the above example output, the function signature was changed from
450 both files (hence two - removals from both file1 and file2, plus + to
451 mean one line that was added does not appear in either file1 nor
452 file2). Also two other lines are the same from file1 but do not appear
453 in file2 (hence prefixed with ).
454 When shown by git diff-tree -c, it compares the parents of a merge
456 commit with the merge result (i.e. file1..fileN are the parents). When
457 shown by git diff-files -c, it compares the two unresolved merge
458 parents with the working tree file (i.e. file1 is stage 2 aka "our
459 version", file2 is stage 3 aka "their version").
460
462 You can choose whether you want to trust the index file entirely (using
463 the --cached flag) or ask the diff logic to show any files that don´t
464 match the stat state as being "tentatively changed". Both of these
465 operations are very useful indeed.
466
468 If --cached is specified, it allows you to ask:
469 show me the differences between HEAD and the current index
472 contents (the ones I´d write with a "git-write-tree")
473 For example, let´s say that you have worked on your working directory,
474 updated some files in the index and are ready to commit. You want to
475 see exactly what you are going to commit, without having to write a new
476 tree object and compare it that way, and to do that, you just do
477 git-diff-index --cached HEAD
480 Example: let´s say I had renamed commit.c to git-commit.c, and I had
481 done an "git-update-index" to make that effective in the index file.
482 "git-diff-files" wouldn´t show anything at all, since the index file
483 matches my working directory. But doing a "git-diff-index" does:
484 torvalds@ppc970:~/git> git-diff-index --cached HEAD
487 -100644 blob 4161aecc6700a2eb579e842af0b7f22b98443f74 commit.c
488 +100644 blob 4161aecc6700a2eb579e842af0b7f22b98443f74 git-commit.c
489 You can see easily that the above is a rename.
490 In fact, "git-diff-index --cached" should always be entirely equivalent
492 to actually doing a "git-write-tree" and comparing that. Except this
493 one is much nicer for the case where you just want to check where you
494 are.
495 So doing a "git-diff-index --cached" is basically very useful when you
497 are asking yourself "what have I already marked for being committed,
498 and what´s the difference to a previous tree".
499
501 The "non-cached" mode takes a different approach, and is potentially
502 the more useful of the two in that what it does can´t be emulated with
503 a "git-write-tree" + "git-diff-tree". Thus that´s the default mode. The
504 non-cached version asks the question:
505 show me the differences between HEAD and the currently checked out
508 tree - index contents _and_ files that aren´t up-to-date
509 which is obviously a very useful question too, since that tells you
510 what you could commit. Again, the output matches the "git-diff-tree -r"
511 output to a tee, but with a twist.
512 The twist is that if some file doesn´t match the index, we don´t have a
514 backing store thing for it, and we use the magic "all-zero" sha1 to
515 show that. So let´s say that you have edited kernel/sched.c, but have
516 not actually done a "git-update-index" on it yet - there is no "object"
517 associated with the new state, and you get:
518 torvalds@ppc970:~/v2.6/linux> git-diff-index HEAD
521 *100644->100664 blob 7476bb......->000000...... kernel/sched.c
522 i.e., it shows that the tree has changed, and that kernel/sched.c has
523 is not up-to-date and may contain new stuff. The all-zero sha1 means
524 that to get the real diff, you need to look at the object in the
525 working directory directly rather than do an object-to-object diff.
526 Note
528 As with other commands of this type, "git-diff-index" does not actually
529 look at the contents of the file at all. So maybe kernel/sched.c hasn´t
530 actually changed, and it´s just that you touched it. In either case,
531 it´s a note that you need to "git-update-index" it to make the index be
532 in sync.
533 Note
536 You can have a mixture of files show up as "has been updated" and "is
537 still dirty in the working directory" together. You can always tell
538 which file is in which state, since the "has been updated" ones show a
539 valid sha1, and the "not in sync with the index" ones will always have
540 the special all-zero sha1.
541
544 Written by Linus Torvalds <torvalds@osdl.org>
545
547 Documentation by David Greaves, Junio C Hamano and the git-list
548 <git@vger.kernel.org>.
549
551 Part of the git(7) suite
552
554 1. diffcore documentation
555 diffcore.html
556Git 1.5.3.3 10/09/2007 GIT-DIFF-INDEX(1)