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 these flags are specified, the object names recorded
  86         for the paths are not updated.  Instead, these options
  87         set and unset the "assume unchanged" bit for the
  88         paths.  When the "assume unchanged" bit is on, Git stops
  89         checking the working tree files for possible
  90         modifications, so you need to manually unset the bit to
  91         tell Git when you change the working tree file. This is
  92         sometimes helpful when working with a big project on a
  93         filesystem that has very slow lstat(2) system call
  94         (e.g. cifs).
  95 +
  96 This option can be also used as a coarse file-level mechanism
  97 to ignore uncommitted changes in tracked files (akin to what
  98 `.gitignore` does for untracked files).
  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 \--::
 165         Do not interpret any more arguments as options.
 166
 167 <file>::
 168         Files to act on.
 169         Note that files beginning with '.' are discarded. This includes
 170         `./file` and `dir/./file`. If you don't want this, then use
 171         cleaner names.
 172         The same applies to directories ending '/' and paths with '//'
 173
 174 Using --refresh
 175 ---------------
 176 '--refresh' does not calculate a new sha1 file or bring the index
 177 up-to-date for mode/content changes. But what it *does* do is to
 178 "re-match" the stat information of a file with the index, so that you
 179 can refresh the index for a file that hasn't been changed but where
 180 the stat entry is out of date.
 181
 182 For example, you'd want to do this after doing a 'git read-tree', to link
 183 up the stat index details with the proper files.
 184
 185 Using --cacheinfo or --info-only
 186 --------------------------------
 187 '--cacheinfo' is used to register a file that is not in the
 188 current working directory.  This is useful for minimum-checkout
 189 merging.
 190
 191 To pretend you have a file with mode and sha1 at path, say:
 192
 193 ----------------
 194 $ git update-index --cacheinfo mode sha1 path
 195 ----------------
 196
 197 '--info-only' is used to register files without placing them in the object
 198 database.  This is useful for status-only repositories.
 199
 200 Both '--cacheinfo' and '--info-only' behave similarly: the index is updated
 201 but the object database isn't.  '--cacheinfo' is useful when the object is
 202 in the database but the file isn't available locally.  '--info-only' is
 203 useful when the file is available, but you do not wish to update the
 204 object database.
 205
 206
 207 Using --index-info
 208 ------------------
 209
 210 `--index-info` is a more powerful mechanism that lets you feed
 211 multiple entry definitions from the standard input, and designed
 212 specifically for scripts.  It can take inputs of three formats:
 213
 214     . mode         SP sha1          TAB path
 215 +
 216 The first format is what "git-apply --index-info"
 217 reports, and used to reconstruct a partial tree
 218 that is used for phony merge base tree when falling
 219 back on 3-way merge.
 220
 221     . mode SP type SP sha1          TAB path
 222 +
 223 The second format is to stuff 'git ls-tree' output
 224 into the index file.
 225
 226     . mode         SP sha1 SP stage TAB path
 227 +
 228 This format is to put higher order stages into the
 229 index file and matches 'git ls-files --stage' output.
 230
 231 To place a higher stage entry to the index, the path should
 232 first be removed by feeding a mode=0 entry for the path, and
 233 then feeding necessary input lines in the third format.
 234
 235 For example, starting with this index:
 236
 237 ------------
 238 $ git ls-files -s
 239 100644 8a1218a1024a212bb3db30becd860315f9f3ac52 0       frotz
 240 ------------
 241
 242 you can feed the following input to `--index-info`:
 243
 244 ------------
 245 $ git update-index --index-info
 246 0 0000000000000000000000000000000000000000      frotz
 247 100644 8a1218a1024a212bb3db30becd860315f9f3ac52 1       frotz
 248 100755 8a1218a1024a212bb3db30becd860315f9f3ac52 2       frotz
 249 ------------
 250
 251 The first line of the input feeds 0 as the mode to remove the
 252 path; the SHA-1 does not matter as long as it is well formatted.
 253 Then the second and third line feeds stage 1 and stage 2 entries
 254 for that path.  After the above, we would end up with this:
 255
 256 ------------
 257 $ git ls-files -s
 258 100644 8a1218a1024a212bb3db30becd860315f9f3ac52 1       frotz
 259 100755 8a1218a1024a212bb3db30becd860315f9f3ac52 2       frotz
 260 ------------
 261
 262
 263 Using ``assume unchanged'' bit
 264 ------------------------------
 265
 266 Many operations in Git depend on your filesystem to have an
 267 efficient `lstat(2)` implementation, so that `st_mtime`
 268 information for working tree files can be cheaply checked to see
 269 if the file contents have changed from the version recorded in
 270 the index file.  Unfortunately, some filesystems have
 271 inefficient `lstat(2)`.  If your filesystem is one of them, you
 272 can set "assume unchanged" bit to paths you have not changed to
 273 cause Git not to do this check.  Note that setting this bit on a
 274 path does not mean Git will check the contents of the file to
 275 see if it has changed -- it makes Git to omit any checking and
 276 assume it has *not* changed.  When you make changes to working
 277 tree files, you have to explicitly tell Git about it by dropping
 278 "assume unchanged" bit, either before or after you modify them.
 279
 280 In order to set "assume unchanged" bit, use `--assume-unchanged`
 281 option.  To unset, use `--no-assume-unchanged`. To see which files
 282 have the "assume unchanged" bit set, use `git ls-files -v`
 283 (see linkgit:git-ls-files[1]).
 284
 285 The command looks at `core.ignorestat` configuration variable.  When
 286 this is true, paths updated with `git update-index paths...` and
 287 paths updated with other Git commands that update both index and
 288 working tree (e.g. 'git apply --index', 'git checkout-index -u',
 289 and 'git read-tree -u') are automatically marked as "assume
 290 unchanged".  Note that "assume unchanged" bit is *not* set if
 291 `git update-index --refresh` finds the working tree file matches
 292 the index (use `git update-index --really-refresh` if you want
 293 to mark them as "assume unchanged").
 294
 295
 296 Examples
 297 --------
 298 To update and refresh only the files already checked out:
 299
 300 ----------------
 301 $ git checkout-index -n -f -a && git update-index --ignore-missing --refresh
 302 ----------------
 303
 304 On an inefficient filesystem with `core.ignorestat` set::
 305 +
 306 ------------
 307 $ git update-index --really-refresh              <1>
 308 $ git update-index --no-assume-unchanged foo.c   <2>
 309 $ git diff --name-only                           <3>
 310 $ edit foo.c
 311 $ git diff --name-only                           <4>
 312 M foo.c
 313 $ git update-index foo.c                         <5>
 314 $ git diff --name-only                           <6>
 315 $ edit foo.c
 316 $ git diff --name-only                           <7>
 317 $ git update-index --no-assume-unchanged foo.c   <8>
 318 $ git diff --name-only                           <9>
 319 M foo.c
 320 ------------
 321 +
 322 <1> forces lstat(2) to set "assume unchanged" bits for paths that match index.
 323 <2> mark the path to be edited.
 324 <3> this does lstat(2) and finds index matches the path.
 325 <4> this does lstat(2) and finds index does *not* match the path.
 326 <5> registering the new version to index sets "assume unchanged" bit.
 327 <6> and it is assumed unchanged.
 328 <7> even after you edit it.
 329 <8> you can tell about the change after the fact.
 330 <9> now it checks with lstat(2) and finds it has been changed.
 331
 332
 333 Skip-worktree bit
 334 -----------------
 335
 336 Skip-worktree bit can be defined in one (long) sentence: When reading
 337 an entry, if it is marked as skip-worktree, then Git pretends its
 338 working directory version is up to date and read the index version
 339 instead.
 340
 341 To elaborate, "reading" means checking for file existence, reading
 342 file attributes or file content. The working directory version may be
 343 present or absent. If present, its content may match against the index
 344 version or not. Writing is not affected by this bit, content safety
 345 is still first priority. Note that Git _can_ update working directory
 346 file, that is marked skip-worktree, if it is safe to do so (i.e.
 347 working directory version matches index version)
 348
 349 Although this bit looks similar to assume-unchanged bit, its goal is
 350 different from assume-unchanged bit's. Skip-worktree also takes
 351 precedence over assume-unchanged bit when both are set.
 352
 353
 354 Configuration
 355 -------------
 356
 357 The command honors `core.filemode` configuration variable.  If
 358 your repository is on a filesystem whose executable bits are
 359 unreliable, this should be set to 'false' (see linkgit:git-config[1]).
 360 This causes the command to ignore differences in file modes recorded
 361 in the index and the file mode on the filesystem if they differ only on
 362 executable bit.   On such an unfortunate filesystem, you may
 363 need to use 'git update-index --chmod='.
 364
 365 Quite similarly, if `core.symlinks` configuration variable is set
 366 to 'false' (see linkgit:git-config[1]), symbolic links are checked out
 367 as plain files, and this command does not modify a recorded file mode
 368 from symbolic link to regular file.
 369
 370 The command looks at `core.ignorestat` configuration variable.  See
 371 'Using "assume unchanged" bit' section above.
 372
 373 The command also looks at `core.trustctime` configuration variable.
 374 It can be useful when the inode change time is regularly modified by
 375 something outside Git (file system crawlers and backup systems use
 376 ctime for marking files processed) (see linkgit:git-config[1]).
 377
 378
 379 SEE ALSO
 380 --------
 381 linkgit:git-config[1],
 382 linkgit:git-add[1],
 383 linkgit:git-ls-files[1]
 384
 385 GIT
 386 ---
 387 Part of the linkgit:git[1] suite