SYNOPSIS
--------
+[verse]
'git-update-index'
[--add] [--remove | --force-remove] [--replace]
[--refresh [-q] [--unmerged] [--ignore-missing]]
[--cacheinfo <mode> <object> <file>]\*
[--chmod=(+|-)x]
+ [--assume-unchanged | --no-assume-unchanged]
+ [--really-refresh]
[--info-only] [--index-info]
[-z] [--stdin]
[--verbose]
--chmod=(+|-)x::
Set the execute permissions on the updated files.
+--assume-unchanged, --no-assume-unchanged::
+ When these flags are specified, the object name recorded
+ for the paths are not updated. Instead, these options
+ sets and unsets the "assume unchanged" bit for the
+ paths. When the "assume unchanged" bit is on, git stops
+ checking the working tree files for possible
+ modifications, so you need to manually unset the bit to
+ tell git when you change the working tree file. This is
+ sometimes helpful when working with a big project on a
+ filesystem that has very slow lstat(2) system call
+ (e.g. cifs).
+
--info-only::
Do not create objects in the object database for all
<file> arguments that follow this flag; just insert
To pretend you have a file with mode and sha1 at path, say:
- $ git-update-index --cacheinfo mode sha1 path
+----------------
+$ git-update-index --cacheinfo mode sha1 path
+----------------
'--info-only' is used to register files without placing them in the object
database. This is useful for status-only repositories.
useful when the file is available, but you do not wish to update the
object database.
+
+Using --index-info
+------------------
+
+`--index-info` is a more powerful mechanism that lets you feed
+multiple entry definitions from the standard input, and designed
+specifically for scripts. It can take inputs of three formats:
+
+ . mode SP sha1 TAB path
++
+The first format is what "git-apply --index-info"
+reports, and used to reconstruct a partial tree
+that is used for phony merge base tree when falling
+back on 3-way merge.
+
+ . mode SP type SP sha1 TAB path
++
+The second format is to stuff git-ls-tree output
+into the index file.
+
+ . mode SP sha1 SP stage TAB path
++
+This format is to put higher order stages into the
+index file and matches git-ls-files --stage output.
+
+To place a higher stage entry to the index, the path should
+first be removed by feeding a mode=0 entry for the path, and
+then feeding necessary input lines in the third format.
+
+For example, starting with this index:
+
+------------
+$ git ls-files -s
+100644 8a1218a1024a212bb3db30becd860315f9f3ac52 0 frotz
+------------
+
+you can feed the following input to `--index-info`:
+
+------------
+$ git update-index --index-info
+0 0000000000000000000000000000000000000000 frotz
+100644 8a1218a1024a212bb3db30becd860315f9f3ac52 1 frotz
+100755 8a1218a1024a212bb3db30becd860315f9f3ac52 2 frotz
+------------
+
+The first line of the input feeds 0 as the mode to remove the
+path; the SHA1 does not matter as long as it is well formatted.
+Then the second and third line feeds stage 1 and stage 2 entries
+for that path. After the above, we would end up with this:
+
+------------
+$ git ls-files -s
+100644 8a1218a1024a212bb3db30becd860315f9f3ac52 1 frotz
+100755 8a1218a1024a212bb3db30becd860315f9f3ac52 2 frotz
+------------
+
+
+Using "assume unchanged" bit
+----------------------------
+
+Many operations in git depend on your filesystem to have an
+efficient `lstat(2)` implementation, so that `st_mtime`
+information for working tree files can be cheaply checked to see
+if the file contents have changed from the version recorded in
+the index file. Unfortunately, some filesystems have
+inefficient `lstat(2)`. If your filesystem is one of them, you
+can set "assume unchanged" bit to paths you have not changed to
+cause git not to do this check. Note that setting this bit on a
+path does not mean git will check the contents of the file to
+see if it has changed -- it makes git to omit any checking and
+assume it has *not* changed. When you make changes to working
+tree files, you have to explicitly tell git about it by dropping
+"assume unchanged" bit, either before or after you modify them.
+
+In order to set "assume unchanged" bit, use `--assume-unchanged`
+option. To unset, use `--no-assume-unchanged`.
+
+The command looks at `core.ignorestat` configuration variable. When
+this is true, paths updated with `git-update-index paths...` and
+paths updated with other git commands that update both index and
+working tree (e.g. `git-apply --index`, `git-checkout-index -u`,
+and `git-read-tree -u`) are automatically marked as "assume
+unchanged". Note that "assume unchanged" bit is *not* set if
+`git-update-index --refresh` finds the working tree file matches
+the index (use `git-update-index --really-refresh` if you want
+to mark them as "assume unchanged").
+
+
Examples
--------
To update and refresh only the files already checked out:
- git-checkout-index -n -f -a && git-update-index --ignore-missing --refresh
+----------------
+$ git-checkout-index -n -f -a && git-update-index --ignore-missing --refresh
+----------------
+
+On an inefficient filesystem with `core.ignorestat` set:
+
+------------
+$ git update-index --really-refresh <1>
+$ git update-index --no-assume-unchanged foo.c <2>
+$ git diff --name-only <3>
+$ edit foo.c
+$ git diff --name-only <4>
+M foo.c
+$ git update-index foo.c <5>
+$ git diff --name-only <6>
+$ edit foo.c
+$ git diff --name-only <7>
+$ git update-index --no-assume-unchanged foo.c <8>
+$ git diff --name-only <9>
+M foo.c
+
+<1> forces lstat(2) to set "assume unchanged" bits for paths
+ that match index.
+<2> mark the path to be edited.
+<3> this does lstat(2) and finds index matches the path.
+<4> this does lstat(2) and finds index does not match the path.
+<5> registering the new version to index sets "assume unchanged" bit.
+<6> and it is assumed unchanged.
+<7> even after you edit it.
+<8> you can tell about the change after the fact.
+<9> now it checks with lstat(2) and finds it has been changed.
+------------
Configuration
The command honors `core.filemode` configuration variable. If
your repository is on an filesystem whose executable bits are
-unreliable, this should be set to 'false'. This causes the
-command to ignore differences in file modes recorded in the
-index and the file mode on the filesystem if they differ only on
+unreliable, this should be set to 'false' (see gitlink:git-repo-config[1]).
+This causes the command to ignore differences in file modes recorded
+in the index and the file mode on the filesystem if they differ only on
executable bit. On such an unfortunate filesystem, you may
need to use `git-update-index --chmod=`.
+The command looks at `core.ignorestat` configuration variable. See
+'Using "assume unchanged" bit' section above.
+
+
+See Also
+--------
+gitlink:git-repo-config[1]
+
+
Author
------
Written by Linus Torvalds <torvalds@osdl.org>