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stat entry is out of date.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 stmtime 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.
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)).
SEE ALSO
git-config(1), git-add(1), git-ls-files(1)
GIT
Part of the git(1) suite
Git 1.8.3.1 11/02/2018 GIT-UPDATE-INDEX(1)