git-commit-vandalism/Documentation/git-clone.txt

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git-clone(1)
============
NAME
----
git-clone - Clone a repository into a new directory
SYNOPSIS
--------
[verse]
'git clone' [--template=<template_directory>]
[-l] [-s] [--no-hardlinks] [-q] [-n] [--bare] [--mirror]
[-o <name>] [-b <name>] [-u <upload-pack>] [--reference <repository>]
[--depth <depth>] [--recursive] [--] <repository> [<directory>]
DESCRIPTION
-----------
Clones a repository into a newly created directory, creates
remote-tracking branches for each branch in the cloned repository
(visible using `git branch -r`), and creates and checks out an
initial branch that is forked from the cloned repository's
currently active branch.
After the clone, a plain `git fetch` without arguments will update
all the remote-tracking branches, and a `git pull` without
arguments will in addition merge the remote master branch into the
current master branch, if any.
This default configuration is achieved by creating references to
the remote branch heads under `$GIT_DIR/refs/remotes/origin` and
by initializing `remote.origin.url` and `remote.origin.fetch`
configuration variables.
OPTIONS
-------
--local::
-l::
When the repository to clone from is on a local machine,
this flag bypasses the normal "git aware" transport
mechanism and clones the repository by making a copy of
HEAD and everything under objects and refs directories.
git-clone: aggressively optimize local clone behaviour. This changes the behaviour of cloning from a repository on the local machine, by defaulting to "-l" (use hardlinks to share files under .git/objects) and making "-l" a no-op. A new option, --no-hardlinks, is also added to cause file-level copy of files under .git/objects while still avoiding the normal "pack to pipe, then receive and index pack" network transfer overhead. The old behaviour of local cloning without -l nor -s is availble by specifying the source repository with the newly introduced file:///path/to/repo.git/ syntax (i.e. "same as network" cloning). * With --no-hardlinks (i.e. have all .git/objects/ copied via cpio) would not catch the source repository corruption, and also risks corrupted recipient repository if an alpha-particle hits memory cell while indexing and resolving deltas. As long as the recipient is created uncorrupted, you have a good back-up. * same-as-network is expensive, but it would catch the breakage of the source repository. It still risks corrupted recipient repository due to hardware failure. As long as the recipient is created uncorrupted, you have a good back-up. * The new default on the same filesystem, as long as the source repository is healthy, it is very likely that the recipient would be, too. Also it is very cheap. You do not get any back-up benefit, though. None of the method is resilient against the source repository corruption, so let's discount that from the comparison. Then the difference with and without --no-hardlinks matters primarily if you value the back-up benefit or not. If you want to use the cloned repository as a back-up, then it is cheaper to do a clone with --no-hardlinks and two git-fsck (source before clone, recipient after clone) than same-as-network clone, especially as you are likely to do a git-fsck on the recipient if you are so paranoid anyway. Which leads me to believe that being able to use file:/// is probably a good idea, if only for testability, but probably of little practical value. We default to hardlinked clone for everyday use, and paranoids can use --no-hardlinks as a way to make a back-up. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-08-02 08:42:36 +02:00
The files under `.git/objects/` directory are hardlinked
to save space when possible. This is now the default when
the source repository is specified with `/path/to/repo`
syntax, so it essentially is a no-op option. To force
copying instead of hardlinking (which may be desirable
if you are trying to make a back-up of your repository),
but still avoid the usual "git aware" transport
mechanism, `--no-hardlinks` can be used.
--no-hardlinks::
Optimize the cloning process from a repository on a
local filesystem by copying files under `.git/objects`
directory.
--shared::
-s::
When the repository to clone is on the local machine,
instead of using hard links, automatically setup
`.git/objects/info/alternates` to share the objects
with the source repository. The resulting repository
starts out without any object of its own.
+
*NOTE*: this is a possibly dangerous operation; do *not* use
it unless you understand what it does. If you clone your
repository using this option and then delete branches (or use any
other git command that makes any existing commit unreferenced) in the
source repository, some objects may become unreferenced (or dangling).
These objects may be removed by normal git operations (such as `git commit`)
which automatically call `git gc --auto`. (See linkgit:git-gc[1].)
If these objects are removed and were referenced by the cloned repository,
then the cloned repository will become corrupt.
+
Note that running `git repack` without the `-l` option in a repository
cloned with `-s` will copy objects from the source repository into a pack
in the cloned repository, removing the disk space savings of `clone -s`.
It is safe, however, to run `git gc`, which uses the `-l` option by
default.
+
If you want to break the dependency of a repository cloned with `-s` on
its source repository, you can simply run `git repack -a` to copy all
objects from the source repository into a pack in the cloned repository.
--reference <repository>::
If the reference repository is on the local machine,
automatically setup `.git/objects/info/alternates` to
obtain objects from the reference repository. Using
an already existing repository as an alternate will
require fewer objects to be copied from the repository
being cloned, reducing network and local storage costs.
+
*NOTE*: see the NOTE for the `--shared` option.
--quiet::
-q::
Operate quietly. Progress is not reported to the standard
error stream. This flag is also passed to the `rsync'
command when given.
--verbose::
-v::
Run verbosely.
--progress::
Progress status is reported on the standard error stream
by default when it is attached to a terminal, unless -q
is specified. This flag forces progress status even if the
standard error stream is not directed to a terminal.
--no-checkout::
-n::
No checkout of HEAD is performed after the clone is complete.
--bare::
Make a 'bare' GIT repository. That is, instead of
creating `<directory>` and placing the administrative
files in `<directory>/.git`, make the `<directory>`
itself the `$GIT_DIR`. This obviously implies the `-n`
because there is nowhere to check out the working tree.
Also the branch heads at the remote are copied directly
to corresponding local branch heads, without mapping
them to `refs/remotes/origin/`. When this option is
used, neither remote-tracking branches nor the related
configuration variables are created.
--mirror::
Set up a mirror of the remote repository. This implies `--bare`.
--origin <name>::
-o <name>::
Instead of using the remote name `origin` to keep track
of the upstream repository, use `<name>`.
--branch <name>::
-b <name>::
Instead of pointing the newly created HEAD to the branch pointed
to by the cloned repository's HEAD, point to `<name>` branch
instead. In a non-bare repository, this is the branch that will
be checked out.
--upload-pack <upload-pack>::
-u <upload-pack>::
When given, and the repository to clone from is accessed
via ssh, this specifies a non-default path for the command
run on the other end.
--template=<template_directory>::
Specify the directory from which templates will be used;
if unset the templates are taken from the installation
defined default, typically `/usr/share/git-core/templates`.
--depth <depth>::
Create a 'shallow' clone with a history truncated to the
specified number of revisions. A shallow repository has a
number of limitations (you cannot clone or fetch from
it, nor push from nor into it), but is adequate if you
are only interested in the recent history of a large project
with a long history, and would want to send in fixes
as patches.
--recursive::
After the clone is created, initialize all submodules within,
using their default settings. This is equivalent to running
`git submodule update --init --recursive` immediately after
the clone is finished. This option is ignored if the cloned
repository does not have a worktree/checkout (i.e. if any of
`--no-checkout`/`-n`, `--bare`, or `--mirror` is given)
<repository>::
The (possibly remote) repository to clone from. See the
<<URLS,URLS>> section below for more information on specifying
repositories.
<directory>::
The name of a new directory to clone into. The "humanish"
part of the source repository is used if no directory is
explicitly given (`repo` for `/path/to/repo.git` and `foo`
for `host.xz:foo/.git`). Cloning into an existing directory
is only allowed if the directory is empty.
:git-clone: 1
include::urls.txt[]
Examples
--------
Clone from upstream::
+
------------
$ git clone git://git.kernel.org/pub/scm/.../linux-2.6 my2.6
$ cd my2.6
$ make
------------
Make a local clone that borrows from the current directory, without checking things out::
+
------------
$ git clone -l -s -n . ../copy
$ cd ../copy
$ git show-branch
------------
Clone from upstream while borrowing from an existing local directory::
+
------------
$ git clone --reference my2.6 \
git://git.kernel.org/pub/scm/.../linux-2.7 \
my2.7
$ cd my2.7
------------
Create a bare repository to publish your changes to the public::
+
------------
$ git clone --bare -l /home/proj/.git /pub/scm/proj.git
------------
Create a repository on the kernel.org machine that borrows from Linus::
+
------------
$ git clone --bare -l -s /pub/scm/.../torvalds/linux-2.6.git \
/pub/scm/.../me/subsys-2.6.git
------------
Author
------
Written by Linus Torvalds <torvalds@osdl.org>
Documentation
--------------
Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>.
GIT
---
Part of the linkgit:git[1] suite