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]
[--ignore-submodules]
[--[no-]split-index]
[--[no-|test-|force-]untracked-cache]
[--really-refresh] [--unresolve] [--again | -g]
[--info-only] [--index-info]
[-z] [--stdin] [--index-version <n>]
[--verbose]
[--] [<file>...]
DESCRIPTION
Modifies the index or directory cache. 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.
-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 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 enabled, the index is split
into two files, $GIT_DIR/index and $GIT_DIR/sharedindex.<SHA-1>.
Changes are accumulated in $GIT_DIR/index while the shared index
file contains all index entries stays unchanged. 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.
This mode is designed for very large indexes that take a
significant amount of time to read or write.
--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.
--
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 with mode and sha1 at path, say:
$ 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.
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 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.
2. mode SP type SP sha1 TAB path
The second format is to stuff git ls-tree output into the index
file.
3. 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
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").
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: When reading an entry, if it is marked as skip-worktree, then Git pretends its working directory version is up to date and read the index version instead. To elaborate, "reading" means checking for file existence, reading file attributes or file content. The working directory version may be present or absent. If present, its content may match against the index version or not. Writing is not affected by this bit, content safety is still first priority. Note that Git can update working directory file, that is marked skip-worktree, if it is safe to do so (i.e. working directory version matches index version) Although this bit looks similar to assume-unchanged bit, its goal is different from assume-unchanged bit's. Skip-worktree also takes precedence over assume-unchanged bit when both are set.
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.
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)).
SEE ALSO
git-config(1), git-add(1), git-ls-files(1)
GIT
Part of the git(1) suite
Opportunity
Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.
Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.
Free Software
Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.
Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.
Free Books
The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.
Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.
Education
Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.
Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.
