show-ref: make --head always show the HEAD ref
[git/git.git] / Documentation / diff-options.txt
1 // Please don't remove this comment as asciidoc behaves badly when
2 // the first non-empty line is ifdef/ifndef. The symptom is that
3 // without this comment the <git-diff-core> attribute conditionally
4 // defined below ends up being defined unconditionally.
5 // Last checked with asciidoc 7.0.2.
6
7 ifndef::git-format-patch[]
8 ifndef::git-diff[]
9 ifndef::git-log[]
10 :git-diff-core: 1
11 endif::git-log[]
12 endif::git-diff[]
13 endif::git-format-patch[]
14
15 ifdef::git-format-patch[]
16 -p::
17 --no-stat::
18 Generate plain patches without any diffstats.
19 endif::git-format-patch[]
20
21 ifndef::git-format-patch[]
22 -p::
23 -u::
24 --patch::
25 Generate patch (see section on generating patches).
26 {git-diff? This is the default.}
27 endif::git-format-patch[]
28
29 -U<n>::
30 --unified=<n>::
31 Generate diffs with <n> lines of context instead of
32 the usual three.
33 ifndef::git-format-patch[]
34 Implies `-p`.
35 endif::git-format-patch[]
36
37 ifndef::git-format-patch[]
38 --raw::
39 Generate the raw format.
40 {git-diff-core? This is the default.}
41 endif::git-format-patch[]
42
43 ifndef::git-format-patch[]
44 --patch-with-raw::
45 Synonym for `-p --raw`.
46 endif::git-format-patch[]
47
48 --minimal::
49 Spend extra time to make sure the smallest possible
50 diff is produced.
51
52 --patience::
53 Generate a diff using the "patience diff" algorithm.
54
55 --histogram::
56 Generate a diff using the "histogram diff" algorithm.
57
58 --diff-algorithm={patience|minimal|histogram|myers}::
59 Choose a diff algorithm. The variants are as follows:
60 +
61 --
62 `default`, `myers`;;
63 The basic greedy diff algorithm. Currently, this is the default.
64 `minimal`;;
65 Spend extra time to make sure the smallest possible diff is
66 produced.
67 `patience`;;
68 Use "patience diff" algorithm when generating patches.
69 `histogram`;;
70 This algorithm extends the patience algorithm to "support
71 low-occurrence common elements".
72 --
73 +
74 For instance, if you configured diff.algorithm variable to a
75 non-default value and want to use the default one, then you
76 have to use `--diff-algorithm=default` option.
77
78 --stat[=<width>[,<name-width>[,<count>]]]::
79 Generate a diffstat. By default, as much space as necessary
80 will be used for the filename part, and the rest for the graph
81 part. Maximum width defaults to terminal width, or 80 columns
82 if not connected to a terminal, and can be overridden by
83 `<width>`. The width of the filename part can be limited by
84 giving another width `<name-width>` after a comma. The width
85 of the graph part can be limited by using
86 `--stat-graph-width=<width>` (affects all commands generating
87 a stat graph) or by setting `diff.statGraphWidth=<width>`
88 (does not affect `git format-patch`).
89 By giving a third parameter `<count>`, you can limit the
90 output to the first `<count>` lines, followed by `...` if
91 there are more.
92 +
93 These parameters can also be set individually with `--stat-width=<width>`,
94 `--stat-name-width=<name-width>` and `--stat-count=<count>`.
95
96 --numstat::
97 Similar to `--stat`, but shows number of added and
98 deleted lines in decimal notation and pathname without
99 abbreviation, to make it more machine friendly. For
100 binary files, outputs two `-` instead of saying
101 `0 0`.
102
103 --shortstat::
104 Output only the last line of the `--stat` format containing total
105 number of modified files, as well as number of added and deleted
106 lines.
107
108 --dirstat[=<param1,param2,...>]::
109 Output the distribution of relative amount of changes for each
110 sub-directory. The behavior of `--dirstat` can be customized by
111 passing it a comma separated list of parameters.
112 The defaults are controlled by the `diff.dirstat` configuration
113 variable (see linkgit:git-config[1]).
114 The following parameters are available:
115 +
116 --
117 `changes`;;
118 Compute the dirstat numbers by counting the lines that have been
119 removed from the source, or added to the destination. This ignores
120 the amount of pure code movements within a file. In other words,
121 rearranging lines in a file is not counted as much as other changes.
122 This is the default behavior when no parameter is given.
123 `lines`;;
124 Compute the dirstat numbers by doing the regular line-based diff
125 analysis, and summing the removed/added line counts. (For binary
126 files, count 64-byte chunks instead, since binary files have no
127 natural concept of lines). This is a more expensive `--dirstat`
128 behavior than the `changes` behavior, but it does count rearranged
129 lines within a file as much as other changes. The resulting output
130 is consistent with what you get from the other `--*stat` options.
131 `files`;;
132 Compute the dirstat numbers by counting the number of files changed.
133 Each changed file counts equally in the dirstat analysis. This is
134 the computationally cheapest `--dirstat` behavior, since it does
135 not have to look at the file contents at all.
136 `cumulative`;;
137 Count changes in a child directory for the parent directory as well.
138 Note that when using `cumulative`, the sum of the percentages
139 reported may exceed 100%. The default (non-cumulative) behavior can
140 be specified with the `noncumulative` parameter.
141 <limit>;;
142 An integer parameter specifies a cut-off percent (3% by default).
143 Directories contributing less than this percentage of the changes
144 are not shown in the output.
145 --
146 +
147 Example: The following will count changed files, while ignoring
148 directories with less than 10% of the total amount of changed files,
149 and accumulating child directory counts in the parent directories:
150 `--dirstat=files,10,cumulative`.
151
152 --summary::
153 Output a condensed summary of extended header information
154 such as creations, renames and mode changes.
155
156 ifndef::git-format-patch[]
157 --patch-with-stat::
158 Synonym for `-p --stat`.
159 endif::git-format-patch[]
160
161 ifndef::git-format-patch[]
162
163 -z::
164 ifdef::git-log[]
165 Separate the commits with NULs instead of with new newlines.
166 +
167 Also, when `--raw` or `--numstat` has been given, do not munge
168 pathnames and use NULs as output field terminators.
169 endif::git-log[]
170 ifndef::git-log[]
171 When `--raw`, `--numstat`, `--name-only` or `--name-status` has been
172 given, do not munge pathnames and use NULs as output field terminators.
173 endif::git-log[]
174 +
175 Without this option, each pathname output will have TAB, LF, double quotes,
176 and backslash characters replaced with `\t`, `\n`, `\"`, and `\\`,
177 respectively, and the pathname will be enclosed in double quotes if
178 any of those replacements occurred.
179
180 --name-only::
181 Show only names of changed files.
182
183 --name-status::
184 Show only names and status of changed files. See the description
185 of the `--diff-filter` option on what the status letters mean.
186
187 --submodule[=<format>]::
188 Specify how differences in submodules are shown. When `--submodule`
189 or `--submodule=log` is given, the 'log' format is used. This format lists
190 the commits in the range like linkgit:git-submodule[1] `summary` does.
191 Omitting the `--submodule` option or specifying `--submodule=short`,
192 uses the 'short' format. This format just shows the names of the commits
193 at the beginning and end of the range. Can be tweaked via the
194 `diff.submodule` configuration variable.
195
196 --color[=<when>]::
197 Show colored diff.
198 The value must be `always` (the default for `<when>`), `never`, or `auto`.
199 The default value is `never`.
200 ifdef::git-diff[]
201 It can be changed by the `color.ui` and `color.diff`
202 configuration settings.
203 endif::git-diff[]
204
205 --no-color::
206 Turn off colored diff.
207 ifdef::git-diff[]
208 This can be used to override configuration settings.
209 endif::git-diff[]
210 It is the same as `--color=never`.
211
212 --word-diff[=<mode>]::
213 Show a word diff, using the <mode> to delimit changed words.
214 By default, words are delimited by whitespace; see
215 `--word-diff-regex` below. The <mode> defaults to 'plain', and
216 must be one of:
217 +
218 --
219 color::
220 Highlight changed words using only colors. Implies `--color`.
221 plain::
222 Show words as `[-removed-]` and `{+added+}`. Makes no
223 attempts to escape the delimiters if they appear in the input,
224 so the output may be ambiguous.
225 porcelain::
226 Use a special line-based format intended for script
227 consumption. Added/removed/unchanged runs are printed in the
228 usual unified diff format, starting with a `+`/`-`/` `
229 character at the beginning of the line and extending to the
230 end of the line. Newlines in the input are represented by a
231 tilde `~` on a line of its own.
232 none::
233 Disable word diff again.
234 --
235 +
236 Note that despite the name of the first mode, color is used to
237 highlight the changed parts in all modes if enabled.
238
239 --word-diff-regex=<regex>::
240 Use <regex> to decide what a word is, instead of considering
241 runs of non-whitespace to be a word. Also implies
242 `--word-diff` unless it was already enabled.
243 +
244 Every non-overlapping match of the
245 <regex> is considered a word. Anything between these matches is
246 considered whitespace and ignored(!) for the purposes of finding
247 differences. You may want to append `|[^[:space:]]` to your regular
248 expression to make sure that it matches all non-whitespace characters.
249 A match that contains a newline is silently truncated(!) at the
250 newline.
251 +
252 The regex can also be set via a diff driver or configuration option, see
253 linkgit:gitattributes[1] or linkgit:git-config[1]. Giving it explicitly
254 overrides any diff driver or configuration setting. Diff drivers
255 override configuration settings.
256
257 --color-words[=<regex>]::
258 Equivalent to `--word-diff=color` plus (if a regex was
259 specified) `--word-diff-regex=<regex>`.
260 endif::git-format-patch[]
261
262 --no-renames::
263 Turn off rename detection, even when the configuration
264 file gives the default to do so.
265
266 ifndef::git-format-patch[]
267 --check::
268 Warn if changes introduce whitespace errors. What are
269 considered whitespace errors is controlled by `core.whitespace`
270 configuration. By default, trailing whitespaces (including
271 lines that solely consist of whitespaces) and a space character
272 that is immediately followed by a tab character inside the
273 initial indent of the line are considered whitespace errors.
274 Exits with non-zero status if problems are found. Not compatible
275 with --exit-code.
276 endif::git-format-patch[]
277
278 --full-index::
279 Instead of the first handful of characters, show the full
280 pre- and post-image blob object names on the "index"
281 line when generating patch format output.
282
283 --binary::
284 In addition to `--full-index`, output a binary diff that
285 can be applied with `git-apply`.
286
287 --abbrev[=<n>]::
288 Instead of showing the full 40-byte hexadecimal object
289 name in diff-raw format output and diff-tree header
290 lines, show only a partial prefix. This is
291 independent of the `--full-index` option above, which controls
292 the diff-patch output format. Non default number of
293 digits can be specified with `--abbrev=<n>`.
294
295 -B[<n>][/<m>]::
296 --break-rewrites[=[<n>][/<m>]]::
297 Break complete rewrite changes into pairs of delete and
298 create. This serves two purposes:
299 +
300 It affects the way a change that amounts to a total rewrite of a file
301 not as a series of deletion and insertion mixed together with a very
302 few lines that happen to match textually as the context, but as a
303 single deletion of everything old followed by a single insertion of
304 everything new, and the number `m` controls this aspect of the -B
305 option (defaults to 60%). `-B/70%` specifies that less than 30% of the
306 original should remain in the result for Git to consider it a total
307 rewrite (i.e. otherwise the resulting patch will be a series of
308 deletion and insertion mixed together with context lines).
309 +
310 When used with -M, a totally-rewritten file is also considered as the
311 source of a rename (usually -M only considers a file that disappeared
312 as the source of a rename), and the number `n` controls this aspect of
313 the -B option (defaults to 50%). `-B20%` specifies that a change with
314 addition and deletion compared to 20% or more of the file's size are
315 eligible for being picked up as a possible source of a rename to
316 another file.
317
318 -M[<n>]::
319 --find-renames[=<n>]::
320 ifndef::git-log[]
321 Detect renames.
322 endif::git-log[]
323 ifdef::git-log[]
324 If generating diffs, detect and report renames for each commit.
325 For following files across renames while traversing history, see
326 `--follow`.
327 endif::git-log[]
328 If `n` is specified, it is a threshold on the similarity
329 index (i.e. amount of addition/deletions compared to the
330 file's size). For example, `-M90%` means Git should consider a
331 delete/add pair to be a rename if more than 90% of the file
332 hasn't changed. Without a `%` sign, the number is to be read as
333 a fraction, with a decimal point before it. I.e., `-M5` becomes
334 0.5, and is thus the same as `-M50%`. Similarly, `-M05` is
335 the same as `-M5%`. To limit detection to exact renames, use
336 `-M100%`.
337
338 -C[<n>]::
339 --find-copies[=<n>]::
340 Detect copies as well as renames. See also `--find-copies-harder`.
341 If `n` is specified, it has the same meaning as for `-M<n>`.
342
343 --find-copies-harder::
344 For performance reasons, by default, `-C` option finds copies only
345 if the original file of the copy was modified in the same
346 changeset. This flag makes the command
347 inspect unmodified files as candidates for the source of
348 copy. This is a very expensive operation for large
349 projects, so use it with caution. Giving more than one
350 `-C` option has the same effect.
351
352 -D::
353 --irreversible-delete::
354 Omit the preimage for deletes, i.e. print only the header but not
355 the diff between the preimage and `/dev/null`. The resulting patch
356 is not meant to be applied with `patch` nor `git apply`; this is
357 solely for people who want to just concentrate on reviewing the
358 text after the change. In addition, the output obviously lack
359 enough information to apply such a patch in reverse, even manually,
360 hence the name of the option.
361 +
362 When used together with `-B`, omit also the preimage in the deletion part
363 of a delete/create pair.
364
365 -l<num>::
366 The `-M` and `-C` options require O(n^2) processing time where n
367 is the number of potential rename/copy targets. This
368 option prevents rename/copy detection from running if
369 the number of rename/copy targets exceeds the specified
370 number.
371
372 ifndef::git-format-patch[]
373 --diff-filter=[(A|C|D|M|R|T|U|X|B)...[*]]::
374 Select only files that are Added (`A`), Copied (`C`),
375 Deleted (`D`), Modified (`M`), Renamed (`R`), have their
376 type (i.e. regular file, symlink, submodule, ...) changed (`T`),
377 are Unmerged (`U`), are
378 Unknown (`X`), or have had their pairing Broken (`B`).
379 Any combination of the filter characters (including none) can be used.
380 When `*` (All-or-none) is added to the combination, all
381 paths are selected if there is any file that matches
382 other criteria in the comparison; if there is no file
383 that matches other criteria, nothing is selected.
384
385 -S<string>::
386 Look for differences that introduce or remove an instance of
387 <string>. Note that this is different than the string simply
388 appearing in diff output; see the 'pickaxe' entry in
389 linkgit:gitdiffcore[7] for more details.
390
391 -G<regex>::
392 Look for differences whose added or removed line matches
393 the given <regex>.
394
395 --pickaxe-all::
396 When `-S` or `-G` finds a change, show all the changes in that
397 changeset, not just the files that contain the change
398 in <string>.
399
400 --pickaxe-regex::
401 Make the <string> not a plain string but an extended POSIX
402 regex to match.
403 endif::git-format-patch[]
404
405 -O<orderfile>::
406 Output the patch in the order specified in the
407 <orderfile>, which has one shell glob pattern per line.
408
409 ifndef::git-format-patch[]
410 -R::
411 Swap two inputs; that is, show differences from index or
412 on-disk file to tree contents.
413
414 --relative[=<path>]::
415 When run from a subdirectory of the project, it can be
416 told to exclude changes outside the directory and show
417 pathnames relative to it with this option. When you are
418 not in a subdirectory (e.g. in a bare repository), you
419 can name which subdirectory to make the output relative
420 to by giving a <path> as an argument.
421 endif::git-format-patch[]
422
423 -a::
424 --text::
425 Treat all files as text.
426
427 --ignore-space-at-eol::
428 Ignore changes in whitespace at EOL.
429
430 -b::
431 --ignore-space-change::
432 Ignore changes in amount of whitespace. This ignores whitespace
433 at line end, and considers all other sequences of one or
434 more whitespace characters to be equivalent.
435
436 -w::
437 --ignore-all-space::
438 Ignore whitespace when comparing lines. This ignores
439 differences even if one line has whitespace where the other
440 line has none.
441
442 --inter-hunk-context=<lines>::
443 Show the context between diff hunks, up to the specified number
444 of lines, thereby fusing hunks that are close to each other.
445
446 -W::
447 --function-context::
448 Show whole surrounding functions of changes.
449
450 ifndef::git-format-patch[]
451 ifndef::git-log[]
452 --exit-code::
453 Make the program exit with codes similar to diff(1).
454 That is, it exits with 1 if there were differences and
455 0 means no differences.
456
457 --quiet::
458 Disable all output of the program. Implies `--exit-code`.
459 endif::git-log[]
460 endif::git-format-patch[]
461
462 --ext-diff::
463 Allow an external diff helper to be executed. If you set an
464 external diff driver with linkgit:gitattributes[5], you need
465 to use this option with linkgit:git-log[1] and friends.
466
467 --no-ext-diff::
468 Disallow external diff drivers.
469
470 --textconv::
471 --no-textconv::
472 Allow (or disallow) external text conversion filters to be run
473 when comparing binary files. See linkgit:gitattributes[5] for
474 details. Because textconv filters are typically a one-way
475 conversion, the resulting diff is suitable for human
476 consumption, but cannot be applied. For this reason, textconv
477 filters are enabled by default only for linkgit:git-diff[1] and
478 linkgit:git-log[1], but not for linkgit:git-format-patch[1] or
479 diff plumbing commands.
480
481 --ignore-submodules[=<when>]::
482 Ignore changes to submodules in the diff generation. <when> can be
483 either "none", "untracked", "dirty" or "all", which is the default
484 Using "none" will consider the submodule modified when it either contains
485 untracked or modified files or its HEAD differs from the commit recorded
486 in the superproject and can be used to override any settings of the
487 'ignore' option in linkgit:git-config[1] or linkgit:gitmodules[5]. When
488 "untracked" is used submodules are not considered dirty when they only
489 contain untracked content (but they are still scanned for modified
490 content). Using "dirty" ignores all changes to the work tree of submodules,
491 only changes to the commits stored in the superproject are shown (this was
492 the behavior until 1.7.0). Using "all" hides all changes to submodules.
493
494 --src-prefix=<prefix>::
495 Show the given source prefix instead of "a/".
496
497 --dst-prefix=<prefix>::
498 Show the given destination prefix instead of "b/".
499
500 --no-prefix::
501 Do not show any source or destination prefix.
502
503 For more detailed explanation on these common options, see also
504 linkgit:gitdiffcore[7].