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