git/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: 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 10:42:36 +04:00
'git-clone' [--template=<template_directory>]
[-l] [-s] [--no-hardlinks] [-q] [-n] [--bare]
[-o <name>] [-u <upload-pack>] [--reference <repository>]
[--depth <depth>] [--] <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 equal to 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 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 10:42:36 +04:00
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.
--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.
--quiet::
-q::
Operate quietly. This flag is passed to "rsync" and
"git-fetch-pack" commands when given.
--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.
--origin <name>::
-o <name>::
Instead of using the remote name 'origin' to keep track
of the upstream repository, use <name> instead.
--upload-pack <upload-pack>::
-u <upload-pack>::
When given, and the repository to clone from is handled
by 'git-fetch-pack', '--exec=<upload-pack>' is passed to
the command to specify 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.
<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 not allowed.
: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[7] suite