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1 git-update-index(1)
2 ===================
3
4 NAME
5 ----
6 git-update-index - Register file contents in the working tree to the index
7
8
9 SYNOPSIS
10 --------
11 [verse]
12 'git update-index'
13 [--add] [--remove | --force-remove] [--replace]
14 [--refresh] [-q] [--unmerged] [--ignore-missing]
15 [(--cacheinfo <mode>,<object>,<file>)...]
16 [--chmod=(+|-)x]
17 [--[no-]assume-unchanged]
18 [--[no-]skip-worktree]
19 [--[no-]ignore-skip-worktree-entries]
20 [--[no-]fsmonitor-valid]
21 [--ignore-submodules]
22 [--[no-]split-index]
23 [--[no-|test-|force-]untracked-cache]
24 [--[no-]fsmonitor]
25 [--really-refresh] [--unresolve] [--again | -g]
26 [--info-only] [--index-info]
27 [-z] [--stdin] [--index-version <n>]
28 [--verbose]
29 [--] [<file>...]
30
31 DESCRIPTION
32 -----------
33 Modifies the index. Each file mentioned is updated into the index and
34 any 'unmerged' or 'needs updating' state is cleared.
35
36 See also linkgit:git-add[1] for a more user-friendly way to do some of
37 the most common operations on the index.
38
39 The way 'git update-index' handles files it is told about can be modified
40 using the various options:
41
42 OPTIONS
43 -------
44 --add::
45 If a specified file isn't in the index already then it's
46 added.
47 Default behaviour is to ignore new files.
48
49 --remove::
50 If a specified file is in the index but is missing then it's
51 removed.
52 Default behavior is to ignore removed file.
53
54 --refresh::
55 Looks at the current index and checks to see if merges or
56 updates are needed by checking stat() information.
57
58 -q::
59 Quiet. If --refresh finds that the index needs an update, the
60 default behavior is to error out. This option makes
61 'git update-index' continue anyway.
62
63 --ignore-submodules::
64 Do not try to update submodules. This option is only respected
65 when passed before --refresh.
66
67 --unmerged::
68 If --refresh finds unmerged changes in the index, the default
69 behavior is to error out. This option makes 'git update-index'
70 continue anyway.
71
72 --ignore-missing::
73 Ignores missing files during a --refresh
74
75 --cacheinfo <mode>,<object>,<path>::
76 --cacheinfo <mode> <object> <path>::
77 Directly insert the specified info into the index. For
78 backward compatibility, you can also give these three
79 arguments as three separate parameters, but new users are
80 encouraged to use a single-parameter form.
81
82 --index-info::
83 Read index information from stdin.
84
85 --chmod=(+|-)x::
86 Set the execute permissions on the updated files.
87
88 --[no-]assume-unchanged::
89 When this flag is specified, the object names recorded
90 for the paths are not updated. Instead, this option
91 sets/unsets the "assume unchanged" bit for the
92 paths. When the "assume unchanged" bit is on, the user
93 promises not to change the file and allows Git to assume
94 that the working tree file matches what is recorded in
95 the index. If you want to change the working tree file,
96 you need to unset the bit to tell Git. This is
97 sometimes helpful when working with a big project on a
98 filesystem that has very slow lstat(2) system call
99 (e.g. cifs).
100 +
101 Git will fail (gracefully) in case it needs to modify this file
102 in the index e.g. when merging in a commit;
103 thus, in case the assumed-untracked file is changed upstream,
104 you will need to handle the situation manually.
105
106 --really-refresh::
107 Like `--refresh`, but checks stat information unconditionally,
108 without regard to the "assume unchanged" setting.
109
110 --[no-]skip-worktree::
111 When one of these flags is specified, the object name recorded
112 for the paths are not updated. Instead, these options
113 set and unset the "skip-worktree" bit for the paths. See
114 section "Skip-worktree bit" below for more information.
115
116
117 --[no-]ignore-skip-worktree-entries::
118 Do not remove skip-worktree (AKA "index-only") entries even when
119 the `--remove` option was specified.
120
121 --[no-]fsmonitor-valid::
122 When one of these flags is specified, the object name recorded
123 for the paths are not updated. Instead, these options
124 set and unset the "fsmonitor valid" bit for the paths. See
125 section "File System Monitor" below for more information.
126
127 -g::
128 --again::
129 Runs 'git update-index' itself on the paths whose index
130 entries are different from those from the `HEAD` commit.
131
132 --unresolve::
133 Restores the 'unmerged' or 'needs updating' state of a
134 file during a merge if it was cleared by accident.
135
136 --info-only::
137 Do not create objects in the object database for all
138 <file> arguments that follow this flag; just insert
139 their object IDs into the index.
140
141 --force-remove::
142 Remove the file from the index even when the working directory
143 still has such a file. (Implies --remove.)
144
145 --replace::
146 By default, when a file `path` exists in the index,
147 'git update-index' refuses an attempt to add `path/file`.
148 Similarly if a file `path/file` exists, a file `path`
149 cannot be added. With --replace flag, existing entries
150 that conflict with the entry being added are
151 automatically removed with warning messages.
152
153 --stdin::
154 Instead of taking list of paths from the command line,
155 read list of paths from the standard input. Paths are
156 separated by LF (i.e. one path per line) by default.
157
158 --verbose::
159 Report what is being added and removed from index.
160
161 --index-version <n>::
162 Write the resulting index out in the named on-disk format version.
163 Supported versions are 2, 3 and 4. The current default version is 2
164 or 3, depending on whether extra features are used, such as
165 `git add -N`.
166 +
167 Version 4 performs a simple pathname compression that reduces index
168 size by 30%-50% on large repositories, which results in faster load
169 time. Version 4 is relatively young (first released in 1.8.0 in
170 October 2012). Other Git implementations such as JGit and libgit2
171 may not support it yet.
172
173 -z::
174 Only meaningful with `--stdin` or `--index-info`; paths are
175 separated with NUL character instead of LF.
176
177 --split-index::
178 --no-split-index::
179 Enable or disable split index mode. If split-index mode is
180 already enabled and `--split-index` is given again, all
181 changes in $GIT_DIR/index are pushed back to the shared index
182 file.
183 +
184 These options take effect whatever the value of the `core.splitIndex`
185 configuration variable (see linkgit:git-config[1]). But a warning is
186 emitted when the change goes against the configured value, as the
187 configured value will take effect next time the index is read and this
188 will remove the intended effect of the option.
189
190 --untracked-cache::
191 --no-untracked-cache::
192 Enable or disable untracked cache feature. Please use
193 `--test-untracked-cache` before enabling it.
194 +
195 These options take effect whatever the value of the `core.untrackedCache`
196 configuration variable (see linkgit:git-config[1]). But a warning is
197 emitted when the change goes against the configured value, as the
198 configured value will take effect next time the index is read and this
199 will remove the intended effect of the option.
200
201 --test-untracked-cache::
202 Only perform tests on the working directory to make sure
203 untracked cache can be used. You have to manually enable
204 untracked cache using `--untracked-cache` or
205 `--force-untracked-cache` or the `core.untrackedCache`
206 configuration variable afterwards if you really want to use
207 it. If a test fails the exit code is 1 and a message
208 explains what is not working as needed, otherwise the exit
209 code is 0 and OK is printed.
210
211 --force-untracked-cache::
212 Same as `--untracked-cache`. Provided for backwards
213 compatibility with older versions of Git where
214 `--untracked-cache` used to imply `--test-untracked-cache` but
215 this option would enable the extension unconditionally.
216
217 --fsmonitor::
218 --no-fsmonitor::
219 Enable or disable files system monitor feature. These options
220 take effect whatever the value of the `core.fsmonitor`
221 configuration variable (see linkgit:git-config[1]). But a warning
222 is emitted when the change goes against the configured value, as
223 the configured value will take effect next time the index is
224 read and this will remove the intended effect of the option.
225
226 \--::
227 Do not interpret any more arguments as options.
228
229 <file>::
230 Files to act on.
231 Note that files beginning with '.' are discarded. This includes
232 `./file` and `dir/./file`. If you don't want this, then use
233 cleaner names.
234 The same applies to directories ending '/' and paths with '//'
235
236 USING --REFRESH
237 ---------------
238 `--refresh` does not calculate a new sha1 file or bring the index
239 up to date for mode/content changes. But what it *does* do is to
240 "re-match" the stat information of a file with the index, so that you
241 can refresh the index for a file that hasn't been changed but where
242 the stat entry is out of date.
243
244 For example, you'd want to do this after doing a 'git read-tree', to link
245 up the stat index details with the proper files.
246
247 USING --CACHEINFO OR --INFO-ONLY
248 --------------------------------
249 `--cacheinfo` is used to register a file that is not in the
250 current working directory. This is useful for minimum-checkout
251 merging.
252
253 To pretend you have a file at path with mode and sha1, say:
254
255 ----------------
256 $ git update-index --add --cacheinfo <mode>,<sha1>,<path>
257 ----------------
258
259 `--info-only` is used to register files without placing them in the object
260 database. This is useful for status-only repositories.
261
262 Both `--cacheinfo` and `--info-only` behave similarly: the index is updated
263 but the object database isn't. `--cacheinfo` is useful when the object is
264 in the database but the file isn't available locally. `--info-only` is
265 useful when the file is available, but you do not wish to update the
266 object database.
267
268
269 USING --INDEX-INFO
270 ------------------
271
272 `--index-info` is a more powerful mechanism that lets you feed
273 multiple entry definitions from the standard input, and designed
274 specifically for scripts. It can take inputs of three formats:
275
276 . mode SP type SP sha1 TAB path
277 +
278 This format is to stuff `git ls-tree` output into the index.
279
280 . mode SP sha1 SP stage TAB path
281 +
282 This format is to put higher order stages into the
283 index file and matches 'git ls-files --stage' output.
284
285 . mode SP sha1 TAB path
286 +
287 This format is no longer produced by any Git command, but is
288 and will continue to be supported by `update-index --index-info`.
289
290 To place a higher stage entry to the index, the path should
291 first be removed by feeding a mode=0 entry for the path, and
292 then feeding necessary input lines in the third format.
293
294 For example, starting with this index:
295
296 ------------
297 $ git ls-files -s
298 100644 8a1218a1024a212bb3db30becd860315f9f3ac52 0 frotz
299 ------------
300
301 you can feed the following input to `--index-info`:
302
303 ------------
304 $ git update-index --index-info
305 0 0000000000000000000000000000000000000000 frotz
306 100644 8a1218a1024a212bb3db30becd860315f9f3ac52 1 frotz
307 100755 8a1218a1024a212bb3db30becd860315f9f3ac52 2 frotz
308 ------------
309
310 The first line of the input feeds 0 as the mode to remove the
311 path; the SHA-1 does not matter as long as it is well formatted.
312 Then the second and third line feeds stage 1 and stage 2 entries
313 for that path. After the above, we would end up with this:
314
315 ------------
316 $ git ls-files -s
317 100644 8a1218a1024a212bb3db30becd860315f9f3ac52 1 frotz
318 100755 8a1218a1024a212bb3db30becd860315f9f3ac52 2 frotz
319 ------------
320
321
322 USING ``ASSUME UNCHANGED'' BIT
323 ------------------------------
324
325 Many operations in Git depend on your filesystem to have an
326 efficient `lstat(2)` implementation, so that `st_mtime`
327 information for working tree files can be cheaply checked to see
328 if the file contents have changed from the version recorded in
329 the index file. Unfortunately, some filesystems have
330 inefficient `lstat(2)`. If your filesystem is one of them, you
331 can set "assume unchanged" bit to paths you have not changed to
332 cause Git not to do this check. Note that setting this bit on a
333 path does not mean Git will check the contents of the file to
334 see if it has changed -- it makes Git to omit any checking and
335 assume it has *not* changed. When you make changes to working
336 tree files, you have to explicitly tell Git about it by dropping
337 "assume unchanged" bit, either before or after you modify them.
338
339 In order to set "assume unchanged" bit, use `--assume-unchanged`
340 option. To unset, use `--no-assume-unchanged`. To see which files
341 have the "assume unchanged" bit set, use `git ls-files -v`
342 (see linkgit:git-ls-files[1]).
343
344 The command looks at `core.ignorestat` configuration variable. When
345 this is true, paths updated with `git update-index paths...` and
346 paths updated with other Git commands that update both index and
347 working tree (e.g. 'git apply --index', 'git checkout-index -u',
348 and 'git read-tree -u') are automatically marked as "assume
349 unchanged". Note that "assume unchanged" bit is *not* set if
350 `git update-index --refresh` finds the working tree file matches
351 the index (use `git update-index --really-refresh` if you want
352 to mark them as "assume unchanged").
353
354 Sometimes users confuse the assume-unchanged bit with the
355 skip-worktree bit. See the final paragraph in the "Skip-worktree bit"
356 section below for an explanation of the differences.
357
358
359 EXAMPLES
360 --------
361 To update and refresh only the files already checked out:
362
363 ----------------
364 $ git checkout-index -n -f -a && git update-index --ignore-missing --refresh
365 ----------------
366
367 On an inefficient filesystem with `core.ignorestat` set::
368 +
369 ------------
370 $ git update-index --really-refresh <1>
371 $ git update-index --no-assume-unchanged foo.c <2>
372 $ git diff --name-only <3>
373 $ edit foo.c
374 $ git diff --name-only <4>
375 M foo.c
376 $ git update-index foo.c <5>
377 $ git diff --name-only <6>
378 $ edit foo.c
379 $ git diff --name-only <7>
380 $ git update-index --no-assume-unchanged foo.c <8>
381 $ git diff --name-only <9>
382 M foo.c
383 ------------
384 +
385 <1> forces lstat(2) to set "assume unchanged" bits for paths that match index.
386 <2> mark the path to be edited.
387 <3> this does lstat(2) and finds index matches the path.
388 <4> this does lstat(2) and finds index does *not* match the path.
389 <5> registering the new version to index sets "assume unchanged" bit.
390 <6> and it is assumed unchanged.
391 <7> even after you edit it.
392 <8> you can tell about the change after the fact.
393 <9> now it checks with lstat(2) and finds it has been changed.
394
395
396 SKIP-WORKTREE BIT
397 -----------------
398
399 Skip-worktree bit can be defined in one (long) sentence: Tell git to
400 avoid writing the file to the working directory when reasonably
401 possible, and treat the file as unchanged when it is not
402 present in the working directory.
403
404 Note that not all git commands will pay attention to this bit, and
405 some only partially support it.
406
407 The update-index flags and the read-tree capabilities relating to the
408 skip-worktree bit predated the introduction of the
409 linkgit:git-sparse-checkout[1] command, which provides a much easier
410 way to configure and handle the skip-worktree bits. If you want to
411 reduce your working tree to only deal with a subset of the files in
412 the repository, we strongly encourage the use of
413 linkgit:git-sparse-checkout[1] in preference to the low-level
414 update-index and read-tree primitives.
415
416 The primary purpose of the skip-worktree bit is to enable sparse
417 checkouts, i.e. to have working directories with only a subset of
418 paths present. When the skip-worktree bit is set, Git commands (such
419 as `switch`, `pull`, `merge`) will avoid writing these files.
420 However, these commands will sometimes write these files anyway in
421 important cases such as conflicts during a merge or rebase. Git
422 commands will also avoid treating the lack of such files as an
423 intentional deletion; for example `git add -u` will not not stage a
424 deletion for these files and `git commit -a` will not make a commit
425 deleting them either.
426
427 Although this bit looks similar to assume-unchanged bit, its goal is
428 different. The assume-unchanged bit is for leaving the file in the
429 working tree but having Git omit checking it for changes and presuming
430 that the file has not been changed (though if it can determine without
431 stat'ing the file that it has changed, it is free to record the
432 changes). skip-worktree tells Git to ignore the absence of the file,
433 avoid updating it when possible with commands that normally update
434 much of the working directory (e.g. `checkout`, `switch`, `pull`,
435 etc.), and not have its absence be recorded in commits. Note that in
436 sparse checkouts (setup by `git sparse-checkout` or by configuring
437 core.sparseCheckout to true), if a file is marked as skip-worktree in
438 the index but is found in the working tree, Git will clear the
439 skip-worktree bit for that file.
440
441 SPLIT INDEX
442 -----------
443
444 This mode is designed for repositories with very large indexes, and
445 aims at reducing the time it takes to repeatedly write these indexes.
446
447 In this mode, the index is split into two files, $GIT_DIR/index and
448 $GIT_DIR/sharedindex.<SHA-1>. Changes are accumulated in
449 $GIT_DIR/index, the split index, while the shared index file contains
450 all index entries and stays unchanged.
451
452 All changes in the split index are pushed back to the shared index
453 file when the number of entries in the split index reaches a level
454 specified by the splitIndex.maxPercentChange config variable (see
455 linkgit:git-config[1]).
456
457 Each time a new shared index file is created, the old shared index
458 files are deleted if their modification time is older than what is
459 specified by the splitIndex.sharedIndexExpire config variable (see
460 linkgit:git-config[1]).
461
462 To avoid deleting a shared index file that is still used, its
463 modification time is updated to the current time every time a new split
464 index based on the shared index file is either created or read from.
465
466 UNTRACKED CACHE
467 ---------------
468
469 This cache is meant to speed up commands that involve determining
470 untracked files such as `git status`.
471
472 This feature works by recording the mtime of the working tree
473 directories and then omitting reading directories and stat calls
474 against files in those directories whose mtime hasn't changed. For
475 this to work the underlying operating system and file system must
476 change the `st_mtime` field of directories if files in the directory
477 are added, modified or deleted.
478
479 You can test whether the filesystem supports that with the
480 `--test-untracked-cache` option. The `--untracked-cache` option used
481 to implicitly perform that test in older versions of Git, but that's
482 no longer the case.
483
484 If you want to enable (or disable) this feature, it is easier to use
485 the `core.untrackedCache` configuration variable (see
486 linkgit:git-config[1]) than using the `--untracked-cache` option to
487 `git update-index` in each repository, especially if you want to do so
488 across all repositories you use, because you can set the configuration
489 variable to `true` (or `false`) in your `$HOME/.gitconfig` just once
490 and have it affect all repositories you touch.
491
492 When the `core.untrackedCache` configuration variable is changed, the
493 untracked cache is added to or removed from the index the next time a
494 command reads the index; while when `--[no-|force-]untracked-cache`
495 are used, the untracked cache is immediately added to or removed from
496 the index.
497
498 Before 2.17, the untracked cache had a bug where replacing a directory
499 with a symlink to another directory could cause it to incorrectly show
500 files tracked by git as untracked. See the "status: add a failing test
501 showing a core.untrackedCache bug" commit to git.git. A workaround for
502 that is (and this might work for other undiscovered bugs in the
503 future):
504
505 ----------------
506 $ git -c core.untrackedCache=false status
507 ----------------
508
509 This bug has also been shown to affect non-symlink cases of replacing
510 a directory with a file when it comes to the internal structures of
511 the untracked cache, but no case has been reported where this resulted in
512 wrong "git status" output.
513
514 There are also cases where existing indexes written by git versions
515 before 2.17 will reference directories that don't exist anymore,
516 potentially causing many "could not open directory" warnings to be
517 printed on "git status". These are new warnings for existing issues
518 that were previously silently discarded.
519
520 As with the bug described above the solution is to one-off do a "git
521 status" run with `core.untrackedCache=false` to flush out the leftover
522 bad data.
523
524 FILE SYSTEM MONITOR
525 -------------------
526
527 This feature is intended to speed up git operations for repos that have
528 large working directories.
529
530 It enables git to work together with a file system monitor (see
531 linkgit:git-fsmonitor{litdd}daemon[1]
532 and the
533 "fsmonitor-watchman" section of linkgit:githooks[5]) that can
534 inform it as to what files have been modified. This enables git to avoid
535 having to lstat() every file to find modified files.
536
537 When used in conjunction with the untracked cache, it can further improve
538 performance by avoiding the cost of scanning the entire working directory
539 looking for new files.
540
541 If you want to enable (or disable) this feature, it is easier to use
542 the `core.fsmonitor` configuration variable (see
543 linkgit:git-config[1]) than using the `--fsmonitor` option to `git
544 update-index` in each repository, especially if you want to do so
545 across all repositories you use, because you can set the configuration
546 variable in your `$HOME/.gitconfig` just once and have it affect all
547 repositories you touch.
548
549 When the `core.fsmonitor` configuration variable is changed, the
550 file system monitor is added to or removed from the index the next time
551 a command reads the index. When `--[no-]fsmonitor` are used, the file
552 system monitor is immediately added to or removed from the index.
553
554 CONFIGURATION
555 -------------
556
557 The command honors `core.filemode` configuration variable. If
558 your repository is on a filesystem whose executable bits are
559 unreliable, this should be set to 'false' (see linkgit:git-config[1]).
560 This causes the command to ignore differences in file modes recorded
561 in the index and the file mode on the filesystem if they differ only on
562 executable bit. On such an unfortunate filesystem, you may
563 need to use 'git update-index --chmod='.
564
565 Quite similarly, if `core.symlinks` configuration variable is set
566 to 'false' (see linkgit:git-config[1]), symbolic links are checked out
567 as plain files, and this command does not modify a recorded file mode
568 from symbolic link to regular file.
569
570 The command looks at `core.ignorestat` configuration variable. See
571 'Using "assume unchanged" bit' section above.
572
573 The command also looks at `core.trustctime` configuration variable.
574 It can be useful when the inode change time is regularly modified by
575 something outside Git (file system crawlers and backup systems use
576 ctime for marking files processed) (see linkgit:git-config[1]).
577
578 The untracked cache extension can be enabled by the
579 `core.untrackedCache` configuration variable (see
580 linkgit:git-config[1]).
581
582 NOTES
583 -----
584
585 Users often try to use the assume-unchanged and skip-worktree bits
586 to tell Git to ignore changes to files that are tracked. This does not
587 work as expected, since Git may still check working tree files against
588 the index when performing certain operations. In general, Git does not
589 provide a way to ignore changes to tracked files, so alternate solutions
590 are recommended.
591
592 For example, if the file you want to change is some sort of config file,
593 the repository can include a sample config file that can then be copied
594 into the ignored name and modified. The repository can even include a
595 script to treat the sample file as a template, modifying and copying it
596 automatically.
597
598 SEE ALSO
599 --------
600 linkgit:git-config[1],
601 linkgit:git-add[1],
602 linkgit:git-ls-files[1]
603
604 GIT
605 ---
606 Part of the linkgit:git[1] suite