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              [--[no-]assume-unchanged]
  18              [--[no-]skip-worktree]
  19              [--ignore-submodules]
  20              [--[no-]split-index]
  21              [--[no-|force-]untracked-cache]
  22              [--really-refresh] [--unresolve] [--again | -g]
  23              [--info-only] [--index-info]
  24              [-z] [--stdin] [--index-version <n>]
  25              [--verbose]
  26              [--] [<file>...]
  27
  28 DESCRIPTION
  29 -----------
  30 Modifies the index or directory cache. Each file mentioned is updated
  31 into the index and any 'unmerged' or 'needs updating' state is
  32 cleared.
  33
  34 See also linkgit:git-add[1] for a more user-friendly way to do some of
  35 the most common operations on the index.
  36
  37 The way 'git update-index' handles files it is told about can be modified
  38 using the various options:
  39
  40 OPTIONS
  41 -------
  42 --add::
  43         If a specified file isn't in the index already then it's
  44         added.
  45         Default behaviour is to ignore new files.
  46
  47 --remove::
  48         If a specified file is in the index but is missing then it's
  49         removed.
  50         Default behavior is to ignore removed file.
  51
  52 --refresh::
  53         Looks at the current index and checks to see if merges or
  54         updates are needed by checking stat() information.
  55
  56 -q::
  57         Quiet.  If --refresh finds that the index needs an update, the
  58         default behavior is to error out.  This option makes
  59         'git update-index' continue anyway.
  60
  61 --ignore-submodules::
  62         Do not try to update submodules.  This option is only respected
  63         when passed before --refresh.
  64
  65 --unmerged::
  66         If --refresh finds unmerged changes in the index, the default
  67         behavior is to error out.  This option makes 'git update-index'
  68         continue anyway.
  69
  70 --ignore-missing::
  71         Ignores missing files during a --refresh
  72
  73 --cacheinfo <mode>,<object>,<path>::
  74 --cacheinfo <mode> <object> <path>::
  75         Directly insert the specified info into the index.  For
  76         backward compatibility, you can also give these three
  77         arguments as three separate parameters, but new users are
  78         encouraged to use a single-parameter form.
  79
  80 --index-info::
  81         Read index information from stdin.
  82
  83 --chmod=(+|-)x::
  84         Set the execute permissions on the updated files.
  85
  86 --[no-]assume-unchanged::
  87         When this flag is specified, the object names recorded
  88         for the paths are not updated.  Instead, this option
  89         sets/unsets the "assume unchanged" bit for the
  90         paths.  When the "assume unchanged" bit is on, the user
  91         promises not to change the file and allows Git to assume
  92         that the working tree file matches what is recorded in
  93         the index.  If you want to change the working tree file,
  94         you need to unset the bit to tell Git.  This is
  95         sometimes helpful when working with a big project on a
  96         filesystem that has very slow lstat(2) system call
  97         (e.g. cifs).
  98 +
  99 Git will fail (gracefully) in case it needs to modify this file
 100 in the index e.g. when merging in a commit;
 101 thus, in case the assumed-untracked file is changed upstream,
 102 you will need to handle the situation manually.
 103
 104 --really-refresh::
 105         Like '--refresh', but checks stat information unconditionally,
 106         without regard to the "assume unchanged" setting.
 107
 108 --[no-]skip-worktree::
 109         When one of these flags is specified, the object name recorded
 110         for the paths are not updated. Instead, these options
 111         set and unset the "skip-worktree" bit for the paths. See
 112         section "Skip-worktree bit" below for more information.
 113
 114 -g::
 115 --again::
 116         Runs 'git update-index' itself on the paths whose index
 117         entries are different from those from the `HEAD` commit.
 118
 119 --unresolve::
 120         Restores the 'unmerged' or 'needs updating' state of a
 121         file during a merge if it was cleared by accident.
 122
 123 --info-only::
 124         Do not create objects in the object database for all
 125         <file> arguments that follow this flag; just insert
 126         their object IDs into the index.
 127
 128 --force-remove::
 129         Remove the file from the index even when the working directory
 130         still has such a file. (Implies --remove.)
 131
 132 --replace::
 133         By default, when a file `path` exists in the index,
 134         'git update-index' refuses an attempt to add `path/file`.
 135         Similarly if a file `path/file` exists, a file `path`
 136         cannot be added.  With --replace flag, existing entries
 137         that conflict with the entry being added are
 138         automatically removed with warning messages.
 139
 140 --stdin::
 141         Instead of taking list of paths from the command line,
 142         read list of paths from the standard input.  Paths are
 143         separated by LF (i.e. one path per line) by default.
 144
 145 --verbose::
 146         Report what is being added and removed from index.
 147
 148 --index-version <n>::
 149         Write the resulting index out in the named on-disk format version.
 150         Supported versions are 2, 3 and 4. The current default version is 2
 151         or 3, depending on whether extra features are used, such as
 152         `git add -N`.
 153 +
 154 Version 4 performs a simple pathname compression that reduces index
 155 size by 30%-50% on large repositories, which results in faster load
 156 time. Version 4 is relatively young (first released in in 1.8.0 in
 157 October 2012). Other Git implementations such as JGit and libgit2
 158 may not support it yet.
 159
 160 -z::
 161         Only meaningful with `--stdin` or `--index-info`; paths are
 162         separated with NUL character instead of LF.
 163
 164 --split-index::
 165 --no-split-index::
 166         Enable or disable split index mode. If enabled, the index is
 167         split into two files, $GIT_DIR/index and $GIT_DIR/sharedindex.<SHA-1>.
 168         Changes are accumulated in $GIT_DIR/index while the shared
 169         index file contains all index entries stays unchanged. If
 170         split-index mode is already enabled and `--split-index` is
 171         given again, all changes in $GIT_DIR/index are pushed back to
 172         the shared index file. This mode is designed for very large
 173         indexes that take a significant amount of time to read or write.
 174
 175 --untracked-cache::
 176 --no-untracked-cache::
 177         Enable or disable untracked cache extension. This could speed
 178         up for commands that involve determining untracked files such
 179         as `git status`. The underlying operating system and file
 180         system must change `st_mtime` field of a directory if files
 181         are added or deleted in that directory.
 182
 183 --force-untracked-cache::
 184         For safety, `--untracked-cache` performs tests on the working
 185         directory to make sure untracked cache can be used. These
 186         tests can take a few seconds. `--force-untracked-cache` can be
 187         used to skip the tests.
 188
 189 \--::
 190         Do not interpret any more arguments as options.
 191
 192 <file>::
 193         Files to act on.
 194         Note that files beginning with '.' are discarded. This includes
 195         `./file` and `dir/./file`. If you don't want this, then use
 196         cleaner names.
 197         The same applies to directories ending '/' and paths with '//'
 198
 199 Using --refresh
 200 ---------------
 201 '--refresh' does not calculate a new sha1 file or bring the index
 202 up-to-date for mode/content changes. But what it *does* do is to
 203 "re-match" the stat information of a file with the index, so that you
 204 can refresh the index for a file that hasn't been changed but where
 205 the stat entry is out of date.
 206
 207 For example, you'd want to do this after doing a 'git read-tree', to link
 208 up the stat index details with the proper files.
 209
 210 Using --cacheinfo or --info-only
 211 --------------------------------
 212 '--cacheinfo' is used to register a file that is not in the
 213 current working directory.  This is useful for minimum-checkout
 214 merging.
 215
 216 To pretend you have a file with mode and sha1 at path, say:
 217
 218 ----------------
 219 $ git update-index --cacheinfo <mode>,<sha1>,<path>
 220 ----------------
 221
 222 '--info-only' is used to register files without placing them in the object
 223 database.  This is useful for status-only repositories.
 224
 225 Both '--cacheinfo' and '--info-only' behave similarly: the index is updated
 226 but the object database isn't.  '--cacheinfo' is useful when the object is
 227 in the database but the file isn't available locally.  '--info-only' is
 228 useful when the file is available, but you do not wish to update the
 229 object database.
 230
 231
 232 Using --index-info
 233 ------------------
 234
 235 `--index-info` is a more powerful mechanism that lets you feed
 236 multiple entry definitions from the standard input, and designed
 237 specifically for scripts.  It can take inputs of three formats:
 238
 239     . mode         SP sha1          TAB path
 240 +
 241 The first format is what "git-apply --index-info"
 242 reports, and used to reconstruct a partial tree
 243 that is used for phony merge base tree when falling
 244 back on 3-way merge.
 245
 246     . mode SP type SP sha1          TAB path
 247 +
 248 The second format is to stuff 'git ls-tree' output
 249 into the index file.
 250
 251     . mode         SP sha1 SP stage TAB path
 252 +
 253 This format is to put higher order stages into the
 254 index file and matches 'git ls-files --stage' output.
 255
 256 To place a higher stage entry to the index, the path should
 257 first be removed by feeding a mode=0 entry for the path, and
 258 then feeding necessary input lines in the third format.
 259
 260 For example, starting with this index:
 261
 262 ------------
 263 $ git ls-files -s
 264 100644 8a1218a1024a212bb3db30becd860315f9f3ac52 0       frotz
 265 ------------
 266
 267 you can feed the following input to `--index-info`:
 268
 269 ------------
 270 $ git update-index --index-info
 271 0 0000000000000000000000000000000000000000      frotz
 272 100644 8a1218a1024a212bb3db30becd860315f9f3ac52 1       frotz
 273 100755 8a1218a1024a212bb3db30becd860315f9f3ac52 2       frotz
 274 ------------
 275
 276 The first line of the input feeds 0 as the mode to remove the
 277 path; the SHA-1 does not matter as long as it is well formatted.
 278 Then the second and third line feeds stage 1 and stage 2 entries
 279 for that path.  After the above, we would end up with this:
 280
 281 ------------
 282 $ git ls-files -s
 283 100644 8a1218a1024a212bb3db30becd860315f9f3ac52 1       frotz
 284 100755 8a1218a1024a212bb3db30becd860315f9f3ac52 2       frotz
 285 ------------
 286
 287
 288 Using ``assume unchanged'' bit
 289 ------------------------------
 290
 291 Many operations in Git depend on your filesystem to have an
 292 efficient `lstat(2)` implementation, so that `st_mtime`
 293 information for working tree files can be cheaply checked to see
 294 if the file contents have changed from the version recorded in
 295 the index file.  Unfortunately, some filesystems have
 296 inefficient `lstat(2)`.  If your filesystem is one of them, you
 297 can set "assume unchanged" bit to paths you have not changed to
 298 cause Git not to do this check.  Note that setting this bit on a
 299 path does not mean Git will check the contents of the file to
 300 see if it has changed -- it makes Git to omit any checking and
 301 assume it has *not* changed.  When you make changes to working
 302 tree files, you have to explicitly tell Git about it by dropping
 303 "assume unchanged" bit, either before or after you modify them.
 304
 305 In order to set "assume unchanged" bit, use `--assume-unchanged`
 306 option.  To unset, use `--no-assume-unchanged`. To see which files
 307 have the "assume unchanged" bit set, use `git ls-files -v`
 308 (see linkgit:git-ls-files[1]).
 309
 310 The command looks at `core.ignorestat` configuration variable.  When
 311 this is true, paths updated with `git update-index paths...` and
 312 paths updated with other Git commands that update both index and
 313 working tree (e.g. 'git apply --index', 'git checkout-index -u',
 314 and 'git read-tree -u') are automatically marked as "assume
 315 unchanged".  Note that "assume unchanged" bit is *not* set if
 316 `git update-index --refresh` finds the working tree file matches
 317 the index (use `git update-index --really-refresh` if you want
 318 to mark them as "assume unchanged").
 319
 320
 321 Examples
 322 --------
 323 To update and refresh only the files already checked out:
 324
 325 ----------------
 326 $ git checkout-index -n -f -a && git update-index --ignore-missing --refresh
 327 ----------------
 328
 329 On an inefficient filesystem with `core.ignorestat` set::
 330 +
 331 ------------
 332 $ git update-index --really-refresh              <1>
 333 $ git update-index --no-assume-unchanged foo.c   <2>
 334 $ git diff --name-only                           <3>
 335 $ edit foo.c
 336 $ git diff --name-only                           <4>
 337 M foo.c
 338 $ git update-index foo.c                         <5>
 339 $ git diff --name-only                           <6>
 340 $ edit foo.c
 341 $ git diff --name-only                           <7>
 342 $ git update-index --no-assume-unchanged foo.c   <8>
 343 $ git diff --name-only                           <9>
 344 M foo.c
 345 ------------
 346 +
 347 <1> forces lstat(2) to set "assume unchanged" bits for paths that match index.
 348 <2> mark the path to be edited.
 349 <3> this does lstat(2) and finds index matches the path.
 350 <4> this does lstat(2) and finds index does *not* match the path.
 351 <5> registering the new version to index sets "assume unchanged" bit.
 352 <6> and it is assumed unchanged.
 353 <7> even after you edit it.
 354 <8> you can tell about the change after the fact.
 355 <9> now it checks with lstat(2) and finds it has been changed.
 356
 357
 358 Skip-worktree bit
 359 -----------------
 360
 361 Skip-worktree bit can be defined in one (long) sentence: When reading
 362 an entry, if it is marked as skip-worktree, then Git pretends its
 363 working directory version is up to date and read the index version
 364 instead.
 365
 366 To elaborate, "reading" means checking for file existence, reading
 367 file attributes or file content. The working directory version may be
 368 present or absent. If present, its content may match against the index
 369 version or not. Writing is not affected by this bit, content safety
 370 is still first priority. Note that Git _can_ update working directory
 371 file, that is marked skip-worktree, if it is safe to do so (i.e.
 372 working directory version matches index version)
 373
 374 Although this bit looks similar to assume-unchanged bit, its goal is
 375 different from assume-unchanged bit's. Skip-worktree also takes
 376 precedence over assume-unchanged bit when both are set.
 377
 378
 379 Configuration
 380 -------------
 381
 382 The command honors `core.filemode` configuration variable.  If
 383 your repository is on a filesystem whose executable bits are
 384 unreliable, this should be set to 'false' (see linkgit:git-config[1]).
 385 This causes the command to ignore differences in file modes recorded
 386 in the index and the file mode on the filesystem if they differ only on
 387 executable bit.   On such an unfortunate filesystem, you may
 388 need to use 'git update-index --chmod='.
 389
 390 Quite similarly, if `core.symlinks` configuration variable is set
 391 to 'false' (see linkgit:git-config[1]), symbolic links are checked out
 392 as plain files, and this command does not modify a recorded file mode
 393 from symbolic link to regular file.
 394
 395 The command looks at `core.ignorestat` configuration variable.  See
 396 'Using "assume unchanged" bit' section above.
 397
 398 The command also looks at `core.trustctime` configuration variable.
 399 It can be useful when the inode change time is regularly modified by
 400 something outside Git (file system crawlers and backup systems use
 401 ctime for marking files processed) (see linkgit:git-config[1]).
 402
 403
 404 SEE ALSO
 405 --------
 406 linkgit:git-config[1],
 407 linkgit:git-add[1],
 408 linkgit:git-ls-files[1]
 409
 410 GIT
 411 ---
 412 Part of the linkgit:git[1] suite