git/Documentation/git-checkout-index.txt

git-checkout-index(1)
=====================
v0.1, May 2005

NAME
----
git-checkout-index - Copy files from the cache to the working directory


SYNOPSIS
--------
'git-checkout-index' [-u] [-q] [-a] [-f] [-n] [--prefix=<string>]
	           [--] <file>...

DESCRIPTION
-----------
Will copy all files listed from the cache to the working directory
(not overwriting existing files).

OPTIONS
-------
-u::
	update stat information for the checked out entries in
	the cache file.

-q::
	be quiet if files exist or are not in the cache

-f::
	forces overwrite of existing files

-a::
	checks out all files in the cache (will then continue to
	process listed files).

-n::
	Don't checkout new files, only refresh files already checked
	out.

--prefix=<string>::
	When creating files, prepend <string> (usually a directory
	including a trailing /)

--::
	Do not interpret any more arguments as options.

Note that the order of the flags matters:

     git-checkout-index -a -f file.c

will first check out all files listed in the cache (but not overwrite
any old ones), and then force-checkout `file.c` a second time (ie that
one *will* overwrite any old contents with the same filename).

Also, 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:

	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 cache, which was not the point.

To update and refresh only the files already checked out:

        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 cache into the specified
directory.
  
NOTE The final "/" is important. The exported name is literally just
prefixed with the specified string, so you can also do something like

    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>.

GIT
---
Part of the gitlink:git[7] suite