GIT-UPDATE-INDEX(1)		  Git Manual		   GIT-UPDATE-INDEX(1)



NAME
       git-update-index - Register file contents in the working tree to the
       index

SYNOPSIS
       git update-index
		    [--add] [--remove | --force-remove] [--replace]
		    [--refresh] [-q] [--unmerged] [--ignore-missing]
		    [(--cacheinfo <mode>,<object>,<file>)...]
		    [--chmod=(+|-)x]
		    [--[no-]assume-unchanged]
		    [--[no-]skip-worktree]
		    [--[no-]ignore-skip-worktree-entries]
		    [--[no-]fsmonitor-valid]
		    [--ignore-submodules]
		    [--[no-]split-index]
		    [--[no-|test-|force-]untracked-cache]
		    [--[no-]fsmonitor]
		    [--really-refresh] [--unresolve] [--again | -g]
		    [--info-only] [--index-info]
		    [-z] [--stdin] [--index-version <n>]
		    [--verbose]
		    [--] [<file>...]


DESCRIPTION
       Modifies the index. Each file mentioned is updated into the index and
       any unmerged or needs updating state is cleared.

       See also git-add(1) for a more user-friendly way to do some of the most
       common operations on the index.

       The way git update-index handles files it is told about can be modified
       using the various options:

OPTIONS
       --add
	   If a specified file isn't in the index already then it's added.
	   Default behaviour is to ignore new files.

       --remove
	   If a specified file is in the index but is missing then it's
	   removed. Default behavior is to ignore removed file.

       --refresh
	   Looks at the current index and checks to see if merges or updates
	   are needed by checking stat() information.

       -q
	   Quiet. If --refresh finds that the index needs an update, the
	   default behavior is to error out. This option makes git
	   update-index continue anyway.

       --ignore-submodules
	   Do not try to update submodules. This option is only respected when
	   passed before --refresh.

       --unmerged
	   If --refresh finds unmerged changes in the index, the default
	   behavior is to error out. This option makes git update-index
	   continue anyway.

       --ignore-missing
	   Ignores missing files during a --refresh

       --cacheinfo <mode>,<object>,<path>, --cacheinfo <mode> <object> <path>
	   Directly insert the specified info into the index. For backward
	   compatibility, you can also give these three arguments as three
	   separate parameters, but new users are encouraged to use a
	   single-parameter form.

       --index-info
	   Read index information from stdin.

       --chmod=(+|-)x
	   Set the execute permissions on the updated files.

       --[no-]assume-unchanged
	   When this flag is specified, the object names recorded for the
	   paths are not updated. Instead, this option sets/unsets the "assume
	   unchanged" bit for the paths. When the "assume unchanged" bit is
	   on, the user promises not to change the file and allows Git to
	   assume that the working tree file matches what is recorded in the
	   index. If you want to change the working tree file, you need to
	   unset the bit to tell Git. This is sometimes helpful when working
	   with a big project on a filesystem that has very slow lstat(2)
	   system call (e.g. cifs).

	   Git will fail (gracefully) in case it needs to modify this file in
	   the index e.g. when merging in a commit; thus, in case the
	   assumed-untracked file is changed upstream, you will need to handle
	   the situation manually.

       --really-refresh
	   Like --refresh, but checks stat information unconditionally,
	   without regard to the "assume unchanged" setting.

       --[no-]skip-worktree
	   When one of these flags is specified, the object name recorded for
	   the paths are not updated. Instead, these options set and unset the
	   "skip-worktree" bit for the paths. See section "Skip-worktree bit"
	   below for more information.

       --[no-]ignore-skip-worktree-entries
	   Do not remove skip-worktree (AKA "index-only") entries even when
	   the --remove option was specified.

       --[no-]fsmonitor-valid
	   When one of these flags is specified, the object name recorded for
	   the paths are not updated. Instead, these options set and unset the
	   "fsmonitor valid" bit for the paths. See section "File System
	   Monitor" below for more information.

       -g, --again
	   Runs git update-index itself on the paths whose index entries are
	   different from those from the HEAD commit.

       --unresolve
	   Restores the unmerged or needs updating state of a file during a
	   merge if it was cleared by accident.

       --info-only
	   Do not create objects in the object database for all <file>
	   arguments that follow this flag; just insert their object IDs into
	   the index.

       --force-remove
	   Remove the file from the index even when the working directory
	   still has such a file. (Implies --remove.)

       --replace
	   By default, when a file path exists in the index, git update-index
	   refuses an attempt to add path/file. Similarly if a file path/file
	   exists, a file path cannot be added. With --replace flag, existing
	   entries that conflict with the entry being added are automatically
	   removed with warning messages.

       --stdin
	   Instead of taking list of paths from the command line, read list of
	   paths from the standard input. Paths are separated by LF (i.e. one
	   path per line) by default.

       --verbose
	   Report what is being added and removed from index.

       --index-version <n>
	   Write the resulting index out in the named on-disk format version.
	   Supported versions are 2, 3 and 4. The current default version is 2
	   or 3, depending on whether extra features are used, such as git add
	   -N.

	   Version 4 performs a simple pathname compression that reduces index
	   size by 30%-50% on large repositories, which results in faster load
	   time. Version 4 is relatively young (first released in 1.8.0 in
	   October 2012). Other Git implementations such as JGit and libgit2
	   may not support it yet.

       -z
	   Only meaningful with --stdin or --index-info; paths are separated
	   with NUL character instead of LF.

       --split-index, --no-split-index
	   Enable or disable split index mode. If split-index mode is already
	   enabled and --split-index is given again, all changes in
	   $GIT_DIR/index are pushed back to the shared index file.

	   These options take effect whatever the value of the core.splitIndex
	   configuration variable (see git-config(1)). But a warning is
	   emitted when the change goes against the configured value, as the
	   configured value will take effect next time the index is read and
	   this will remove the intended effect of the option.

       --untracked-cache, --no-untracked-cache
	   Enable or disable untracked cache feature. Please use
	   --test-untracked-cache before enabling it.

	   These options take effect whatever the value of the
	   core.untrackedCache configuration variable (see git-config(1)). But
	   a warning is emitted when the change goes against the configured
	   value, as the configured value will take effect next time the index
	   is read and this will remove the intended effect of the option.

       --test-untracked-cache
	   Only perform tests on the working directory to make sure untracked
	   cache can be used. You have to manually enable untracked cache
	   using --untracked-cache or --force-untracked-cache or the
	   core.untrackedCache configuration variable afterwards if you really
	   want to use it. If a test fails the exit code is 1 and a message
	   explains what is not working as needed, otherwise the exit code is
	   0 and OK is printed.

       --force-untracked-cache
	   Same as --untracked-cache. Provided for backwards compatibility
	   with older versions of Git where --untracked-cache used to imply
	   --test-untracked-cache but this option would enable the extension
	   unconditionally.

       --fsmonitor, --no-fsmonitor
	   Enable or disable files system monitor feature. These options take
	   effect whatever the value of the core.fsmonitor configuration
	   variable (see git-config(1)). But a warning is emitted when the
	   change goes against the configured value, as the configured value
	   will take effect next time the index is read and this will remove
	   the intended effect of the option.

       --
	   Do not interpret any more arguments as options.

       <file>
	   Files to act on. Note that files beginning with .  are discarded.
	   This includes ./file and dir/./file. If you don't want this, then
	   use cleaner names. The same applies to directories ending / and
	   paths with //

USING --REFRESH
       --refresh does not calculate a new sha1 file or bring the index up to
       date for mode/content changes. But what it does do is to "re-match" the
       stat information of a file with the index, so that you can refresh the
       index for a file that hasn't been changed but where the stat entry is
       out of date.

       For example, you'd want to do this after doing a git read-tree, to link
       up the stat index details with the proper files.

USING --CACHEINFO OR --INFO-ONLY
       --cacheinfo is used to register a file that is not in the current
       working directory. This is useful for minimum-checkout merging.

       To pretend you have a file at path with mode and sha1, say:

	   $ git update-index --add --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.

       Both --cacheinfo and --info-only behave similarly: the index is updated
       but the object database isn't. --cacheinfo is useful when the object is
       in the database but the file isn't available locally. --info-only is
       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:

	1. mode SP type SP sha1 TAB path

	   This format is to stuff git ls-tree output into the index.

	2. 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.

	3. mode SP sha1 TAB path

	   This format is no longer produced by any Git command, but is and
	   will continue to be supported by update-index --index-info.

       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
       SHA-1 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. To see which files have the
       "assume unchanged" bit set, use git ls-files -v (see git-ls-files(1)).

       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").

       Sometimes users confuse the assume-unchanged bit with the skip-worktree
       bit. See the final paragraph in the "Skip-worktree bit" section below
       for an explanation of the differences.

EXAMPLES
       To update and refresh only the files already checked out:

	   $ 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.

SKIP-WORKTREE BIT
       Skip-worktree bit can be defined in one (long) sentence: Tell git to
       avoid writing the file to the working directory when reasonably
       possible, and treat the file as unchanged when it is not present in the
       working directory.

       Note that not all git commands will pay attention to this bit, and some
       only partially support it.

       The update-index flags and the read-tree capabilities relating to the
       skip-worktree bit predated the introduction of the git-sparse-
       checkout(1) command, which provides a much easier way to configure and
       handle the skip-worktree bits. If you want to reduce your working tree
       to only deal with a subset of the files in the repository, we strongly
       encourage the use of git-sparse-checkout(1) in preference to the
       low-level update-index and read-tree primitives.

       The primary purpose of the skip-worktree bit is to enable sparse
       checkouts, i.e. to have working directories with only a subset of paths
       present. When the skip-worktree bit is set, Git commands (such as
       switch, pull, merge) will avoid writing these files. However, these
       commands will sometimes write these files anyway in important cases
       such as conflicts during a merge or rebase. Git commands will also
       avoid treating the lack of such files as an intentional deletion; for
       example git add -u will not stage a deletion for these files and git
       commit -a will not make a commit deleting them either.

       Although this bit looks similar to assume-unchanged bit, its goal is
       different. The assume-unchanged bit is for leaving the file in the
       working tree but having Git omit checking it for changes and presuming
       that the file has not been changed (though if it can determine without
       stat'ing the file that it has changed, it is free to record the
       changes). skip-worktree tells Git to ignore the absence of the file,
       avoid updating it when possible with commands that normally update much
       of the working directory (e.g. checkout, switch, pull, etc.), and not
       have its absence be recorded in commits. Note that in sparse checkouts
       (setup by git sparse-checkout or by configuring core.sparseCheckout to
       true), if a file is marked as skip-worktree in the index but is found
       in the working tree, Git will clear the skip-worktree bit for that
       file.

SPLIT INDEX
       This mode is designed for repositories with very large indexes, and
       aims at reducing the time it takes to repeatedly write these indexes.

       In this mode, the index is split into two files, $GIT_DIR/index and
       $GIT_DIR/sharedindex.<SHA-1>. Changes are accumulated in
       $GIT_DIR/index, the split index, while the shared index file contains
       all index entries and stays unchanged.

       All changes in the split index are pushed back to the shared index file
       when the number of entries in the split index reaches a level specified
       by the splitIndex.maxPercentChange config variable (see git-config(1)).

       Each time a new shared index file is created, the old shared index
       files are deleted if their modification time is older than what is
       specified by the splitIndex.sharedIndexExpire config variable (see git-
       config(1)).

       To avoid deleting a shared index file that is still used, its
       modification time is updated to the current time every time a new split
       index based on the shared index file is either created or read from.

UNTRACKED CACHE
       This cache is meant to speed up commands that involve determining
       untracked files such as git status.

       This feature works by recording the mtime of the working tree
       directories and then omitting reading directories and stat calls
       against files in those directories whose mtime hasn't changed. For this
       to work the underlying operating system and file system must change the
       st_mtime field of directories if files in the directory are added,
       modified or deleted.

       You can test whether the filesystem supports that with the
       --test-untracked-cache option. The --untracked-cache option used to
       implicitly perform that test in older versions of Git, but that's no
       longer the case.

       If you want to enable (or disable) this feature, it is easier to use
       the core.untrackedCache configuration variable (see git-config(1)) than
       using the --untracked-cache option to git update-index in each
       repository, especially if you want to do so across all repositories you
       use, because you can set the configuration variable to true (or false)
       in your $HOME/.gitconfig just once and have it affect all repositories
       you touch.

       When the core.untrackedCache configuration variable is changed, the
       untracked cache is added to or removed from the index the next time a
       command reads the index; while when --[no-|force-]untracked-cache are
       used, the untracked cache is immediately added to or removed from the
       index.

       Before 2.17, the untracked cache had a bug where replacing a directory
       with a symlink to another directory could cause it to incorrectly show
       files tracked by git as untracked. See the "status: add a failing test
       showing a core.untrackedCache bug" commit to git.git. A workaround for
       that is (and this might work for other undiscovered bugs in the
       future):

	   $ git -c core.untrackedCache=false status


       This bug has also been shown to affect non-symlink cases of replacing a
       directory with a file when it comes to the internal structures of the
       untracked cache, but no case has been reported where this resulted in
       wrong "git status" output.

       There are also cases where existing indexes written by git versions
       before 2.17 will reference directories that don't exist anymore,
       potentially causing many "could not open directory" warnings to be
       printed on "git status". These are new warnings for existing issues
       that were previously silently discarded.

       As with the bug described above the solution is to one-off do a "git
       status" run with core.untrackedCache=false to flush out the leftover
       bad data.

FILE SYSTEM MONITOR
       This feature is intended to speed up git operations for repos that have
       large working directories.

       It enables git to work together with a file system monitor (see git-
       fsmonitor--daemon(1) and the "fsmonitor-watchman" section of
       githooks(5)) that can inform it as to what files have been modified.
       This enables git to avoid having to lstat() every file to find modified
       files.

       When used in conjunction with the untracked cache, it can further
       improve performance by avoiding the cost of scanning the entire working
       directory looking for new files.

       If you want to enable (or disable) this feature, it is easier to use
       the core.fsmonitor configuration variable (see git-config(1)) than
       using the --fsmonitor option to git update-index in each repository,
       especially if you want to do so across all repositories you use,
       because you can set the configuration variable in your $HOME/.gitconfig
       just once and have it affect all repositories you touch.

       When the core.fsmonitor configuration variable is changed, the file
       system monitor is added to or removed from the index the next time a
       command reads the index. When --[no-]fsmonitor are used, the file
       system monitor is immediately added to or removed from the index.

CONFIGURATION
       The command honors core.filemode configuration variable. If your
       repository is on a filesystem whose executable bits are unreliable,
       this should be set to false (see git-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=.

       Quite similarly, if core.symlinks configuration variable is set to
       false (see git-config(1)), symbolic links are checked out as plain
       files, and this command does not modify a recorded file mode from
       symbolic link to regular file.

       The command looks at core.ignorestat configuration variable. See Using
       "assume unchanged" bit section above.

       The command also looks at core.trustctime configuration variable. It
       can be useful when the inode change time is regularly modified by
       something outside Git (file system crawlers and backup systems use
       ctime for marking files processed) (see git-config(1)).

       The untracked cache extension can be enabled by the core.untrackedCache
       configuration variable (see git-config(1)).

NOTES
       Users often try to use the assume-unchanged and skip-worktree bits to
       tell Git to ignore changes to files that are tracked. This does not
       work as expected, since Git may still check working tree files against
       the index when performing certain operations. In general, Git does not
       provide a way to ignore changes to tracked files, so alternate
       solutions are recommended.

       For example, if the file you want to change is some sort of config
       file, the repository can include a sample config file that can then be
       copied into the ignored name and modified. The repository can even
       include a script to treat the sample file as a template, modifying and
       copying it automatically.

SEE ALSO
       git-config(1), git-add(1), git-ls-files(1)

GIT
       Part of the git(1) suite



Git 2.38.4			  05/16/2024		   GIT-UPDATE-INDEX(1)