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 You should remember that an explicit 'git add' operation will
  97 still cause the file to be refreshed from the working tree.
  98 Git will fail (gracefully) in case it needs to modify this file
  99 in the index e.g. when merging in a commit;
 100 thus, in case the assumed-untracked file is changed upstream,
 101 you will need to handle the situation manually.
 102
 103 --really-refresh::
 104         Like '--refresh', but checks stat information unconditionally,
 105         without regard to the "assume unchanged" setting.
 106
 107 --skip-worktree::
 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 -z::
 149         Only meaningful with `--stdin`; paths are separated with
 150         NUL character instead of LF.
 151
 152 \--::
 153         Do not interpret any more arguments as options.
 154
 155 <file>::
 156         Files to act on.
 157         Note that files beginning with '.' are discarded. This includes
 158         `./file` and `dir/./file`. If you don't want this, then use
 159         cleaner names.
 160         The same applies to directories ending '/' and paths with '//'
 161
 162 Using --refresh
 163 ---------------
 164 '--refresh' does not calculate a new sha1 file or bring the index
 165 up-to-date for mode/content changes. But what it *does* do is to
 166 "re-match" the stat information of a file with the index, so that you
 167 can refresh the index for a file that hasn't been changed but where
 168 the stat entry is out of date.
 169
 170 For example, you'd want to do this after doing a 'git read-tree', to link
 171 up the stat index details with the proper files.
 172
 173 Using --cacheinfo or --info-only
 174 --------------------------------
 175 '--cacheinfo' is used to register a file that is not in the
 176 current working directory.  This is useful for minimum-checkout
 177 merging.
 178
 179 To pretend you have a file with mode and sha1 at path, say:
 180
 181 ----------------
 182 $ git update-index --cacheinfo mode sha1 path
 183 ----------------
 184
 185 '--info-only' is used to register files without placing them in the object
 186 database.  This is useful for status-only repositories.
 187
 188 Both '--cacheinfo' and '--info-only' behave similarly: the index is updated
 189 but the object database isn't.  '--cacheinfo' is useful when the object is
 190 in the database but the file isn't available locally.  '--info-only' is
 191 useful when the file is available, but you do not wish to update the
 192 object database.
 193
 194
 195 Using --index-info
 196 ------------------
 197
 198 `--index-info` is a more powerful mechanism that lets you feed
 199 multiple entry definitions from the standard input, and designed
 200 specifically for scripts.  It can take inputs of three formats:
 201
 202     . mode         SP sha1          TAB path
 203 +
 204 The first format is what "git-apply --index-info"
 205 reports, and used to reconstruct a partial tree
 206 that is used for phony merge base tree when falling
 207 back on 3-way merge.
 208
 209     . mode SP type SP sha1          TAB path
 210 +
 211 The second format is to stuff 'git ls-tree' output
 212 into the index file.
 213
 214     . mode         SP sha1 SP stage TAB path
 215 +
 216 This format is to put higher order stages into the
 217 index file and matches 'git ls-files --stage' output.
 218
 219 To place a higher stage entry to the index, the path should
 220 first be removed by feeding a mode=0 entry for the path, and
 221 then feeding necessary input lines in the third format.
 222
 223 For example, starting with this index:
 224
 225 ------------
 226 $ git ls-files -s
 227 100644 8a1218a1024a212bb3db30becd860315f9f3ac52 0       frotz
 228 ------------
 229
 230 you can feed the following input to `--index-info`:
 231
 232 ------------
 233 $ git update-index --index-info
 234 0 0000000000000000000000000000000000000000      frotz
 235 100644 8a1218a1024a212bb3db30becd860315f9f3ac52 1       frotz
 236 100755 8a1218a1024a212bb3db30becd860315f9f3ac52 2       frotz
 237 ------------
 238
 239 The first line of the input feeds 0 as the mode to remove the
 240 path; the SHA1 does not matter as long as it is well formatted.
 241 Then the second and third line feeds stage 1 and stage 2 entries
 242 for that path.  After the above, we would end up with this:
 243
 244 ------------
 245 $ git ls-files -s
 246 100644 8a1218a1024a212bb3db30becd860315f9f3ac52 1       frotz
 247 100755 8a1218a1024a212bb3db30becd860315f9f3ac52 2       frotz
 248 ------------
 249
 250
 251 Using ``assume unchanged'' bit
 252 ------------------------------
 253
 254 Many operations in git depend on your filesystem to have an
 255 efficient `lstat(2)` implementation, so that `st_mtime`
 256 information for working tree files can be cheaply checked to see
 257 if the file contents have changed from the version recorded in
 258 the index file.  Unfortunately, some filesystems have
 259 inefficient `lstat(2)`.  If your filesystem is one of them, you
 260 can set "assume unchanged" bit to paths you have not changed to
 261 cause git not to do this check.  Note that setting this bit on a
 262 path does not mean git will check the contents of the file to
 263 see if it has changed -- it makes git to omit any checking and
 264 assume it has *not* changed.  When you make changes to working
 265 tree files, you have to explicitly tell git about it by dropping
 266 "assume unchanged" bit, either before or after you modify them.
 267
 268 In order to set "assume unchanged" bit, use `--assume-unchanged`
 269 option.  To unset, use `--no-assume-unchanged`.
 270
 271 The command looks at `core.ignorestat` configuration variable.  When
 272 this is true, paths updated with `git update-index paths...` and
 273 paths updated with other git commands that update both index and
 274 working tree (e.g. 'git apply --index', 'git checkout-index -u',
 275 and 'git read-tree -u') are automatically marked as "assume
 276 unchanged".  Note that "assume unchanged" bit is *not* set if
 277 `git update-index --refresh` finds the working tree file matches
 278 the index (use `git update-index --really-refresh` if you want
 279 to mark them as "assume unchanged").
 280
 281
 282 Examples
 283 --------
 284 To update and refresh only the files already checked out:
 285
 286 ----------------
 287 $ git checkout-index -n -f -a && git update-index --ignore-missing --refresh
 288 ----------------
 289
 290 On an inefficient filesystem with `core.ignorestat` set::
 291 +
 292 ------------
 293 $ git update-index --really-refresh              <1>
 294 $ git update-index --no-assume-unchanged foo.c   <2>
 295 $ git diff --name-only                           <3>
 296 $ edit foo.c
 297 $ git diff --name-only                           <4>
 298 M foo.c
 299 $ git update-index foo.c                         <5>
 300 $ git diff --name-only                           <6>
 301 $ edit foo.c
 302 $ git diff --name-only                           <7>
 303 $ git update-index --no-assume-unchanged foo.c   <8>
 304 $ git diff --name-only                           <9>
 305 M foo.c
 306 ------------
 307 +
 308 <1> forces lstat(2) to set "assume unchanged" bits for paths that match index.
 309 <2> mark the path to be edited.
 310 <3> this does lstat(2) and finds index matches the path.
 311 <4> this does lstat(2) and finds index does *not* match the path.
 312 <5> registering the new version to index sets "assume unchanged" bit.
 313 <6> and it is assumed unchanged.
 314 <7> even after you edit it.
 315 <8> you can tell about the change after the fact.
 316 <9> now it checks with lstat(2) and finds it has been changed.
 317
 318
 319 Skip-worktree bit
 320 -----------------
 321
 322 Skip-worktree bit can be defined in one (long) sentence: When reading
 323 an entry, if it is marked as skip-worktree, then Git pretends its
 324 working directory version is up to date and read the index version
 325 instead.
 326
 327 To elaborate, "reading" means checking for file existence, reading
 328 file attributes or file content. The working directory version may be
 329 present or absent. If present, its content may match against the index
 330 version or not. Writing is not affected by this bit, content safety
 331 is still first priority. Note that Git _can_ update working directory
 332 file, that is marked skip-worktree, if it is safe to do so (i.e.
 333 working directory version matches index version)
 334
 335 Although this bit looks similar to assume-unchanged bit, its goal is
 336 different from assume-unchanged bit's. Skip-worktree also takes
 337 precedence over assume-unchanged bit when both are set.
 338
 339
 340 Configuration
 341 -------------
 342
 343 The command honors `core.filemode` configuration variable.  If
 344 your repository is on a filesystem whose executable bits are
 345 unreliable, this should be set to 'false' (see linkgit:git-config[1]).
 346 This causes the command to ignore differences in file modes recorded
 347 in the index and the file mode on the filesystem if they differ only on
 348 executable bit.   On such an unfortunate filesystem, you may
 349 need to use 'git update-index --chmod='.
 350
 351 Quite similarly, if `core.symlinks` configuration variable is set
 352 to 'false' (see linkgit:git-config[1]), symbolic links are checked out
 353 as plain files, and this command does not modify a recorded file mode
 354 from symbolic link to regular file.
 355
 356 The command looks at `core.ignorestat` configuration variable.  See
 357 'Using "assume unchanged" bit' section above.
 358
 359 The command also looks at `core.trustctime` configuration variable.
 360 It can be useful when the inode change time is regularly modified by
 361 something outside Git (file system crawlers and backup systems use
 362 ctime for marking files processed) (see linkgit:git-config[1]).
 363
 364
 365 SEE ALSO
 366 --------
 367 linkgit:git-config[1],
 368 linkgit:git-add[1]
 369
 370
 371 Author
 372 ------
 373 Written by Linus Torvalds <torvalds@osdl.org>
 374
 375 Documentation
 376 --------------
 377 Documentation by David Greaves, Junio C Hamano and the git-list <git@vger.kernel.org>.
 378
 379 GIT
 380 ---
 381 Part of the linkgit:git[1] suite