Merge branch 'maint-1.7.3' into maint
[git/git.git] / Documentation / git-update-index.txt
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 [--assume-unchanged | --no-assume-unchanged]
18 [--skip-worktree | --no-skip-worktree]
19 [--ignore-submodules]
20 [--really-refresh] [--unresolve] [--again | -g]
21 [--info-only] [--index-info]
22 [-z] [--stdin]
23 [--verbose]
24 [--] [<file>...]
25
26 DESCRIPTION
27 -----------
28 Modifies the index or directory cache. Each file mentioned is updated
29 into the index and any 'unmerged' or 'needs updating' state is
30 cleared.
31
32 See also linkgit:git-add[1] for a more user-friendly way to do some of
33 the most common operations on the index.
34
35 The way 'git update-index' handles files it is told about can be modified
36 using the various options:
37
38 OPTIONS
39 -------
40 --add::
41 If a specified file isn't in the index already then it's
42 added.
43 Default behaviour is to ignore new files.
44
45 --remove::
46 If a specified file is in the index but is missing then it's
47 removed.
48 Default behavior is to ignore removed file.
49
50 --refresh::
51 Looks at the current index and checks to see if merges or
52 updates are needed by checking stat() information.
53
54 -q::
55 Quiet. If --refresh finds that the index needs an update, the
56 default behavior is to error out. This option makes
57 'git update-index' continue anyway.
58
59 --ignore-submodules::
60 Do not try to update submodules. This option is only respected
61 when passed before --refresh.
62
63 --unmerged::
64 If --refresh finds unmerged changes in the index, the default
65 behavior is to error out. This option makes 'git update-index'
66 continue anyway.
67
68 --ignore-missing::
69 Ignores missing files during a --refresh
70
71 --cacheinfo <mode> <object> <path>::
72 Directly insert the specified info into the index.
73
74 --index-info::
75 Read index information from stdin.
76
77 --chmod=(+|-)x::
78 Set the execute permissions on the updated files.
79
80 --assume-unchanged::
81 --no-assume-unchanged::
82 When these flags are specified, the object names recorded
83 for the paths are not updated. Instead, these options
84 set and unset the "assume unchanged" bit for the
85 paths. When the "assume unchanged" bit is on, git stops
86 checking the working tree files for possible
87 modifications, so you need to manually unset the bit to
88 tell git when you change the working tree file. This is
89 sometimes helpful when working with a big project on a
90 filesystem that has very slow lstat(2) system call
91 (e.g. cifs).
92 +
93 This option can be also used as a coarse file-level mechanism
94 to ignore uncommitted changes in tracked files (akin to what
95 `.gitignore` does for untracked files).
96 Git will fail (gracefully) in case it needs to modify this file
97 in the index e.g. when merging in a commit;
98 thus, in case the assumed-untracked file is changed upstream,
99 you will need to handle the situation manually.
100
101 --really-refresh::
102 Like '--refresh', but checks stat information unconditionally,
103 without regard to the "assume unchanged" setting.
104
105 --skip-worktree::
106 --no-skip-worktree::
107 When one of these flags is specified, the object name recorded
108 for the paths are not updated. Instead, these options
109 set and unset the "skip-worktree" bit for the paths. See
110 section "Skip-worktree bit" below for more information.
111
112 -g::
113 --again::
114 Runs 'git update-index' itself on the paths whose index
115 entries are different from those from the `HEAD` commit.
116
117 --unresolve::
118 Restores the 'unmerged' or 'needs updating' state of a
119 file during a merge if it was cleared by accident.
120
121 --info-only::
122 Do not create objects in the object database for all
123 <file> arguments that follow this flag; just insert
124 their object IDs into the index.
125
126 --force-remove::
127 Remove the file from the index even when the working directory
128 still has such a file. (Implies --remove.)
129
130 --replace::
131 By default, when a file `path` exists in the index,
132 'git update-index' refuses an attempt to add `path/file`.
133 Similarly if a file `path/file` exists, a file `path`
134 cannot be added. With --replace flag, existing entries
135 that conflict with the entry being added are
136 automatically removed with warning messages.
137
138 --stdin::
139 Instead of taking list of paths from the command line,
140 read list of paths from the standard input. Paths are
141 separated by LF (i.e. one path per line) by default.
142
143 --verbose::
144 Report what is being added and removed from index.
145
146 -z::
147 Only meaningful with `--stdin` or `--index-info`; paths are
148 separated with NUL character instead of LF.
149
150 \--::
151 Do not interpret any more arguments as options.
152
153 <file>::
154 Files to act on.
155 Note that files beginning with '.' are discarded. This includes
156 `./file` and `dir/./file`. If you don't want this, then use
157 cleaner names.
158 The same applies to directories ending '/' and paths with '//'
159
160 Using --refresh
161 ---------------
162 '--refresh' does not calculate a new sha1 file or bring the index
163 up-to-date for mode/content changes. But what it *does* do is to
164 "re-match" the stat information of a file with the index, so that you
165 can refresh the index for a file that hasn't been changed but where
166 the stat entry is out of date.
167
168 For example, you'd want to do this after doing a 'git read-tree', to link
169 up the stat index details with the proper files.
170
171 Using --cacheinfo or --info-only
172 --------------------------------
173 '--cacheinfo' is used to register a file that is not in the
174 current working directory. This is useful for minimum-checkout
175 merging.
176
177 To pretend you have a file with mode and sha1 at path, say:
178
179 ----------------
180 $ git update-index --cacheinfo mode sha1 path
181 ----------------
182
183 '--info-only' is used to register files without placing them in the object
184 database. This is useful for status-only repositories.
185
186 Both '--cacheinfo' and '--info-only' behave similarly: the index is updated
187 but the object database isn't. '--cacheinfo' is useful when the object is
188 in the database but the file isn't available locally. '--info-only' is
189 useful when the file is available, but you do not wish to update the
190 object database.
191
192
193 Using --index-info
194 ------------------
195
196 `--index-info` is a more powerful mechanism that lets you feed
197 multiple entry definitions from the standard input, and designed
198 specifically for scripts. It can take inputs of three formats:
199
200 . mode SP sha1 TAB path
201 +
202 The first format is what "git-apply --index-info"
203 reports, and used to reconstruct a partial tree
204 that is used for phony merge base tree when falling
205 back on 3-way merge.
206
207 . mode SP type SP sha1 TAB path
208 +
209 The second format is to stuff 'git ls-tree' output
210 into the index file.
211
212 . mode SP sha1 SP stage TAB path
213 +
214 This format is to put higher order stages into the
215 index file and matches 'git ls-files --stage' output.
216
217 To place a higher stage entry to the index, the path should
218 first be removed by feeding a mode=0 entry for the path, and
219 then feeding necessary input lines in the third format.
220
221 For example, starting with this index:
222
223 ------------
224 $ git ls-files -s
225 100644 8a1218a1024a212bb3db30becd860315f9f3ac52 0 frotz
226 ------------
227
228 you can feed the following input to `--index-info`:
229
230 ------------
231 $ git update-index --index-info
232 0 0000000000000000000000000000000000000000 frotz
233 100644 8a1218a1024a212bb3db30becd860315f9f3ac52 1 frotz
234 100755 8a1218a1024a212bb3db30becd860315f9f3ac52 2 frotz
235 ------------
236
237 The first line of the input feeds 0 as the mode to remove the
238 path; the SHA1 does not matter as long as it is well formatted.
239 Then the second and third line feeds stage 1 and stage 2 entries
240 for that path. After the above, we would end up with this:
241
242 ------------
243 $ git ls-files -s
244 100644 8a1218a1024a212bb3db30becd860315f9f3ac52 1 frotz
245 100755 8a1218a1024a212bb3db30becd860315f9f3ac52 2 frotz
246 ------------
247
248
249 Using ``assume unchanged'' bit
250 ------------------------------
251
252 Many operations in git depend on your filesystem to have an
253 efficient `lstat(2)` implementation, so that `st_mtime`
254 information for working tree files can be cheaply checked to see
255 if the file contents have changed from the version recorded in
256 the index file. Unfortunately, some filesystems have
257 inefficient `lstat(2)`. If your filesystem is one of them, you
258 can set "assume unchanged" bit to paths you have not changed to
259 cause git not to do this check. Note that setting this bit on a
260 path does not mean git will check the contents of the file to
261 see if it has changed -- it makes git to omit any checking and
262 assume it has *not* changed. When you make changes to working
263 tree files, you have to explicitly tell git about it by dropping
264 "assume unchanged" bit, either before or after you modify them.
265
266 In order to set "assume unchanged" bit, use `--assume-unchanged`
267 option. To unset, use `--no-assume-unchanged`.
268
269 The command looks at `core.ignorestat` configuration variable. When
270 this is true, paths updated with `git update-index paths...` and
271 paths updated with other git commands that update both index and
272 working tree (e.g. 'git apply --index', 'git checkout-index -u',
273 and 'git read-tree -u') are automatically marked as "assume
274 unchanged". Note that "assume unchanged" bit is *not* set if
275 `git update-index --refresh` finds the working tree file matches
276 the index (use `git update-index --really-refresh` if you want
277 to mark them as "assume unchanged").
278
279
280 Examples
281 --------
282 To update and refresh only the files already checked out:
283
284 ----------------
285 $ git checkout-index -n -f -a && git update-index --ignore-missing --refresh
286 ----------------
287
288 On an inefficient filesystem with `core.ignorestat` set::
289 +
290 ------------
291 $ git update-index --really-refresh <1>
292 $ git update-index --no-assume-unchanged foo.c <2>
293 $ git diff --name-only <3>
294 $ edit foo.c
295 $ git diff --name-only <4>
296 M foo.c
297 $ git update-index foo.c <5>
298 $ git diff --name-only <6>
299 $ edit foo.c
300 $ git diff --name-only <7>
301 $ git update-index --no-assume-unchanged foo.c <8>
302 $ git diff --name-only <9>
303 M foo.c
304 ------------
305 +
306 <1> forces lstat(2) to set "assume unchanged" bits for paths that match index.
307 <2> mark the path to be edited.
308 <3> this does lstat(2) and finds index matches the path.
309 <4> this does lstat(2) and finds index does *not* match the path.
310 <5> registering the new version to index sets "assume unchanged" bit.
311 <6> and it is assumed unchanged.
312 <7> even after you edit it.
313 <8> you can tell about the change after the fact.
314 <9> now it checks with lstat(2) and finds it has been changed.
315
316
317 Skip-worktree bit
318 -----------------
319
320 Skip-worktree bit can be defined in one (long) sentence: When reading
321 an entry, if it is marked as skip-worktree, then Git pretends its
322 working directory version is up to date and read the index version
323 instead.
324
325 To elaborate, "reading" means checking for file existence, reading
326 file attributes or file content. The working directory version may be
327 present or absent. If present, its content may match against the index
328 version or not. Writing is not affected by this bit, content safety
329 is still first priority. Note that Git _can_ update working directory
330 file, that is marked skip-worktree, if it is safe to do so (i.e.
331 working directory version matches index version)
332
333 Although this bit looks similar to assume-unchanged bit, its goal is
334 different from assume-unchanged bit's. Skip-worktree also takes
335 precedence over assume-unchanged bit when both are set.
336
337
338 Configuration
339 -------------
340
341 The command honors `core.filemode` configuration variable. If
342 your repository is on a filesystem whose executable bits are
343 unreliable, this should be set to 'false' (see linkgit:git-config[1]).
344 This causes the command to ignore differences in file modes recorded
345 in the index and the file mode on the filesystem if they differ only on
346 executable bit. On such an unfortunate filesystem, you may
347 need to use 'git update-index --chmod='.
348
349 Quite similarly, if `core.symlinks` configuration variable is set
350 to 'false' (see linkgit:git-config[1]), symbolic links are checked out
351 as plain files, and this command does not modify a recorded file mode
352 from symbolic link to regular file.
353
354 The command looks at `core.ignorestat` configuration variable. See
355 'Using "assume unchanged" bit' section above.
356
357 The command also looks at `core.trustctime` configuration variable.
358 It can be useful when the inode change time is regularly modified by
359 something outside Git (file system crawlers and backup systems use
360 ctime for marking files processed) (see linkgit:git-config[1]).
361
362
363 SEE ALSO
364 --------
365 linkgit:git-config[1],
366 linkgit:git-add[1]
367
368 GIT
369 ---
370 Part of the linkgit:git[1] suite