The order of the flags used to matter, but not anymore.
-Just doing "git-checkout-index" does nothing. You probably meant
-"git-checkout-index -a". And if you want to force it, you want
-"git-checkout-index -f -a".
+Just doing `git-checkout-index` does nothing. You probably meant
+`git-checkout-index -a`. And if you want to force it, you want
+`git-checkout-index -f -a`.
Intuitiveness is not the goal here. Repeatability is. The reason for
-the "no arguments means no work" thing is that from scripts you are
-supposed to be able to do things like:
+the "no arguments means no work" behavior is that from scripts you are
+supposed to be able to do:
- find . -name '*.h' -print0 | xargs -0 git-checkout-index -f --
+----------------
+$ find . -name '*.h' -print0 | xargs -0 git-checkout-index -f --
+----------------
which will force all existing `*.h` files to be replaced with their
cached copies. If an empty command line implied "all", then this would
force-refresh everything in the index, which was not the point.
-To update and refresh only the files already checked out:
+The `--` is just a good idea when you know the rest will be filenames;
+it will prevent problems with a filename of, for example, `-a`.
+Using `--` is probably a good policy in scripts.
- git-checkout-index -n -f -a && git-update-index --ignore-missing --refresh
-Oh, and the "--" is just a good idea when you know the rest will be
-filenames. Just so that you wouldn't have a filename of "-a" causing
-problems (not possible in the above example, but get used to it in
-scripting!).
-
-The prefix ability basically makes it trivial to use
-git-checkout-index as an "export as tree" function. Just read the
-desired tree into the index, and do a
-
- git-checkout-index --prefix=git-export-dir/ -a
-
-and git-checkout-index will "export" the index into the specified
+EXAMPLES
+--------
+To update and refresh only the files already checked out::
++
+----------------
+$ git-checkout-index -n -f -a && git-update-index --ignore-missing --refresh
+----------------
+
+Using `git-checkout-index` to "export an entire tree"::
+ The prefix ability basically makes it trivial to use
+ `git-checkout-index` as an "export as tree" function.
+ Just read the desired tree into the index, and do:
++
+----------------
+$ git-checkout-index --prefix=git-export-dir/ -a
+----------------
++
+`git-checkout-index` will "export" the index into the specified
directory.
++
+The final "/" is important. The exported name is literally just
+prefixed with the specified string. Contrast this with the
+following example.
-NOTE The final "/" is important. The exported name is literally just
-prefixed with the specified string, so you can also do something like
+Export files with a prefix::
++
+----------------
+$ git-checkout-index --prefix=.merged- Makefile
+----------------
++
+This will check out the currently cached copy of `Makefile`
+into the file `.merged-Makefile`.
- git-checkout-index --prefix=.merged- Makefile
-
-to check out the currently cached copy of `Makefile` into the file
-`.merged-Makefile`
Author
------
Written by Linus Torvalds <torvalds@osdl.org>
+
Documentation
--------------
-Documentation by David Greaves, Junio C Hamano and the git-list <git@vger.kernel.org>.
+Documentation by David Greaves,
+Junio C Hamano and the git-list <git@vger.kernel.org>.
+
GIT
---
-----------
Reads the tree information given by <tree-ish> into the index,
but does not actually *update* any of the files it "caches". (see:
-git-checkout-index)
+gitlink:git-checkout-index[1])
Optionally, it can merge a tree into the index, perform a
-fast-forward (i.e. 2-way) merge, or a 3-way merge, with the -m
-flag. When used with -m, the -u flag causes it to also update
+fast-forward (i.e. 2-way) merge, or a 3-way merge, with the `-m`
+flag. When used with `-m`, the `-u` flag causes it to also update
the files in the work tree with the result of the merge.
-Trivial merges are done by "git-read-tree" itself. Only conflicting paths
-will be in unmerged state when "git-read-tree" returns.
+Trivial merges are done by `git-read-tree` itself. Only conflicting paths
+will be in unmerged state when `git-read-tree` returns.
OPTIONS
-------
Merging
-------
-If '-m' is specified, "git-read-tree" can perform 3 kinds of
+If `-m` is specified, `git-read-tree` can perform 3 kinds of
merge, a single tree merge if only 1 tree is given, a
fast-forward merge with 2 trees, or a 3-way merge if 3 trees are
provided.
Single Tree Merge
~~~~~~~~~~~~~~~~~
If only 1 tree is specified, git-read-tree operates as if the user did not
-specify '-m', except that if the original index has an entry for a
+specify `-m`, except that if the original index has an entry for a
given pathname, and the contents of the path matches with the tree
being read, the stat info from the index is used. (In other words, the
index's stat()s take precedence over the merged tree's).
-That means that if you do a "git-read-tree -m <newtree>" followed by a
-"git-checkout-index -f -u -a", the "git-checkout-index" only checks out
+That means that if you do a `git-read-tree -m <newtree>` followed by a
+`git-checkout-index -f -u -a`, the `git-checkout-index` only checks out
the stuff that really changed.
-This is used to avoid unnecessary false hits when "git-diff-files" is
-run after git-read-tree.
+This is used to avoid unnecessary false hits when `git-diff-files` is
+run after `git-read-tree`.
Two Tree Merge
~~~~~~~~~~~~~~
-Typically, this is invoked as "git-read-tree -m $H $M", where $H
+Typically, this is invoked as `git-read-tree -m $H $M`, where $H
is the head commit of the current repository, and $M is the head
of a foreign tree, which is simply ahead of $H (i.e. we are in a
fast forward situation).
2. The user wants to fast-forward to $M.
-In this case, the "git-read-tree -m $H $M" command makes sure
+In this case, the `git-read-tree -m $H $M` command makes sure
that no local change is lost as the result of this "merge".
Here are the "carry forward" rules:
When this form of git-read-tree returns successfully, you can
see what "local changes" you made are carried forward by running
-"git-diff-index --cached $M". Note that this does not
-necessarily match "git-diff-index --cached $H" would have
+`git-diff-index --cached $M`. Note that this does not
+necessarily match `git-diff-index --cached $H` would have
produced before such a two tree merge. This is because of cases
18 and 19 --- if you already had the changes in $M (e.g. maybe
-you picked it up via e-mail in a patch form), "git-diff-index
---cached $H" would have told you about the change before this
-merge, but it would not show in "git-diff-index --cached $M"
+you picked it up via e-mail in a patch form), `git-diff-index
+--cached $H` would have told you about the change before this
+merge, but it would not show in `git-diff-index --cached $M`
output after two-tree merge.
Each "index" entry has two bits worth of "stage" state. stage 0 is the
normal one, and is the only one you'd see in any kind of normal use.
-However, when you do "git-read-tree" with three trees, the "stage"
+However, when you do `git-read-tree` with three trees, the "stage"
starts out at 1.
This means that you can do
- git-read-tree -m <tree1> <tree2> <tree3>
+----------------
+$ git-read-tree -m <tree1> <tree2> <tree3>
+----------------
and you will end up with an index with all of the <tree1> entries in
"stage1", all of the <tree2> entries in "stage2" and all of the
<tree3> entries in "stage3".
-Furthermore, "git-read-tree" has special-case logic that says: if you see
+Furthermore, `git-read-tree` has special-case logic that says: if you see
a file that matches in all respects in the following states, it
"collapses" back to "stage0":
- stage 1 and stage 3 are the same and stage 2 is different take
stage 2 (some work has been done on stage 2)
-The "git-write-tree" command refuses to write a nonsensical tree, and it
+The `git-write-tree` command refuses to write a nonsensical tree, and it
will complain about unmerged entries if it sees a single entry that is not
stage 0.
matching "stage1" entry if it exists too. .. all the normal
trivial rules ..
-You would normally use "git-merge-index" with supplied
-"git-merge-one-file" to do this last step. The script
+You would normally use `git-merge-index` with supplied
+`git-merge-one-file` to do this last step. The script
does not touch the files in the work tree, and the entire merge
happens in the index file. In other words, there is no need to
worry about what is in the working directory, since it is never
changes. To illustrate, suppose you start from what has been
commited last to your repository:
- $ JC=`git-rev-parse --verify "HEAD^0"`
- $ git-checkout-index -f -u -a $JC
+----------------
+$ JC=`git-rev-parse --verify "HEAD^0"`
+$ git-checkout-index -f -u -a $JC
+----------------
You do random edits, without running git-update-index. And then
you notice that the tip of your "upstream" tree has advanced
since you pulled from him:
- $ git-fetch rsync://.... linus
- $ LT=`cat .git/MERGE_HEAD`
+----------------
+$ git-fetch rsync://.... linus
+$ LT=`cat .git/MERGE_HEAD`
+----------------
Your work tree is still based on your HEAD ($JC), but you have
some edits since. Three-way merge makes sure that you have not
added or modified index entries since $JC, and if you haven't,
then does the right thing. So with the following sequence:
- $ git-read-tree -m -u `git-merge-base $JC $LT` $JC $LT
- $ git-merge-index git-merge-one-file -a
- $ echo "Merge with Linus" | \
- git-commit-tree `git-write-tree` -p $JC -p $LT
+----------------
+$ git-read-tree -m -u `git-merge-base $JC $LT` $JC $LT
+$ git-merge-index git-merge-one-file -a
+$ echo "Merge with Linus" | \
+ git-commit-tree `git-write-tree` -p $JC -p $LT
+----------------
-what you would commit is a pure merge between $JC and LT without
+what you would commit is a pure merge between $JC and $LT without
your work-in-progress changes, and your work tree would be
updated to the result of the merge.
projects / git.git / commitdiff