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