config: Introduce diff.algorithm variable

[git] / Documentation / git-pull.txt

git-pull(1)
===========

NAME
----
git-pull - Fetch from and merge with another repository or a local branch


SYNOPSIS
--------
[verse]
'git pull' [options] [<repository> [<refspec>...]]


DESCRIPTION
-----------

Incorporates changes from a remote repository into the current
branch.  In its default mode, `git pull` is shorthand for
`git fetch` followed by `git merge FETCH_HEAD`.

More precisely, 'git pull' runs 'git fetch' with the given
parameters and calls 'git merge' to merge the retrieved branch
heads into the current branch.
With `--rebase`, it runs 'git rebase' instead of 'git merge'.

<repository> should be the name of a remote repository as
passed to linkgit:git-fetch[1].  <refspec> can name an
arbitrary remote ref (for example, the name of a tag) or even
a collection of refs with corresponding remote-tracking branches
(e.g., refs/heads/{asterisk}:refs/remotes/origin/{asterisk}),
but usually it is the name of a branch in the remote repository.

Default values for <repository> and <branch> are read from the
"remote" and "merge" configuration for the current branch
as set by linkgit:git-branch[1] `--track`.

Assume the following history exists and the current branch is
"`master`":

------------
          A---B---C master on origin
         /
    D---E---F---G master
------------

Then "`git pull`" will fetch and replay the changes from the remote
`master` branch since it diverged from the local `master` (i.e., `E`)
until its current commit (`C`) on top of `master` and record the
result in a new commit along with the names of the two parent commits
and a log message from the user describing the changes.

------------
          A---B---C remotes/origin/master
         /         \
    D---E---F---G---H master
------------

See linkgit:git-merge[1] for details, including how conflicts
are presented and handled.

In git 1.7.0 or later, to cancel a conflicting merge, use
`git reset --merge`.  *Warning*: In older versions of git, running 'git pull'
with uncommitted changes is discouraged: while possible, it leaves you
in a state that may be hard to back out of in the case of a conflict.

If any of the remote changes overlap with local uncommitted changes,
the merge will be automatically cancelled and the work tree untouched.
It is generally best to get any local changes in working order before
pulling or stash them away with linkgit:git-stash[1].

OPTIONS
-------

Options meant for 'git pull' itself and the underlying 'git merge'
must be given before the options meant for 'git fetch'.

-q::
--quiet::
        This is passed to both underlying git-fetch to squelch reporting of
        during transfer, and underlying git-merge to squelch output during
        merging.

-v::
--verbose::
        Pass --verbose to git-fetch and git-merge.

--[no-]recurse-submodules[=yes|on-demand|no]::
        This option controls if new commits of all populated submodules should
        be fetched too (see linkgit:git-config[1] and linkgit:gitmodules[5]).
        That might be necessary to get the data needed for merging submodule
        commits, a feature git learned in 1.7.3. Notice that the result of a
        merge will not be checked out in the submodule, "git submodule update"
        has to be called afterwards to bring the work tree up to date with the
        merge result.

Options related to merging
~~~~~~~~~~~~~~~~~~~~~~~~~~

include::merge-options.txt[]

:git-pull: 1

-r::
--rebase::
        Rebase the current branch on top of the upstream branch after
        fetching.  If there is a remote-tracking branch corresponding to
        the upstream branch and the upstream branch was rebased since last
        fetched, the rebase uses that information to avoid rebasing
        non-local changes.
+
See `pull.rebase`, `branch.<name>.rebase` and `branch.autosetuprebase` in
linkgit:git-config[1] if you want to make `git pull` always use
`--rebase` instead of merging.
+
[NOTE]
This is a potentially _dangerous_ mode of operation.
It rewrites history, which does not bode well when you
published that history already.  Do *not* use this option
unless you have read linkgit:git-rebase[1] carefully.

--no-rebase::
        Override earlier --rebase.

Options related to fetching
~~~~~~~~~~~~~~~~~~~~~~~~~~~

include::fetch-options.txt[]

include::pull-fetch-param.txt[]

include::urls-remotes.txt[]

include::merge-strategies.txt[]

DEFAULT BEHAVIOUR
-----------------

Often people use `git pull` without giving any parameter.
Traditionally, this has been equivalent to saying `git pull
origin`.  However, when configuration `branch.<name>.remote` is
present while on branch `<name>`, that value is used instead of
`origin`.

In order to determine what URL to use to fetch from, the value
of the configuration `remote.<origin>.url` is consulted
and if there is not any such variable, the value on `URL: ` line
in `$GIT_DIR/remotes/<origin>` file is used.

In order to determine what remote branches to fetch (and
optionally store in the remote-tracking branches) when the command is
run without any refspec parameters on the command line, values
of the configuration variable `remote.<origin>.fetch` are
consulted, and if there aren't any, `$GIT_DIR/remotes/<origin>`
file is consulted and its `Pull: ` lines are used.
In addition to the refspec formats described in the OPTIONS
section, you can have a globbing refspec that looks like this:

------------
refs/heads/*:refs/remotes/origin/*
------------

A globbing refspec must have a non-empty RHS (i.e. must store
what were fetched in remote-tracking branches), and its LHS and RHS
must end with `/*`.  The above specifies that all remote
branches are tracked using remote-tracking branches in
`refs/remotes/origin/` hierarchy under the same name.

The rule to determine which remote branch to merge after
fetching is a bit involved, in order not to break backward
compatibility.

If explicit refspecs were given on the command
line of `git pull`, they are all merged.

When no refspec was given on the command line, then `git pull`
uses the refspec from the configuration or
`$GIT_DIR/remotes/<origin>`.  In such cases, the following
rules apply:

. If `branch.<name>.merge` configuration for the current
  branch `<name>` exists, that is the name of the branch at the
  remote site that is merged.

. If the refspec is a globbing one, nothing is merged.

. Otherwise the remote branch of the first refspec is merged.


EXAMPLES
--------

* Update the remote-tracking branches for the repository
  you cloned from, then merge one of them into your
  current branch:
+
------------------------------------------------
$ git pull, git pull origin
------------------------------------------------
+
Normally the branch merged in is the HEAD of the remote repository,
but the choice is determined by the branch.<name>.remote and
branch.<name>.merge options; see linkgit:git-config[1] for details.

* Merge into the current branch the remote branch `next`:
+
------------------------------------------------
$ git pull origin next
------------------------------------------------
+
This leaves a copy of `next` temporarily in FETCH_HEAD, but
does not update any remote-tracking branches. Using remote-tracking
branches, the same can be done by invoking fetch and merge:
+
------------------------------------------------
$ git fetch origin
$ git merge origin/next
------------------------------------------------


If you tried a pull which resulted in a complex conflicts and
would want to start over, you can recover with 'git reset'.


BUGS
----
Using --recurse-submodules can only fetch new commits in already checked
out submodules right now. When e.g. upstream added a new submodule in the
just fetched commits of the superproject the submodule itself can not be
fetched, making it impossible to check out that submodule later without
having to do a fetch again. This is expected to be fixed in a future git
version.

SEE ALSO
--------
linkgit:git-fetch[1], linkgit:git-merge[1], linkgit:git-config[1]

GIT
---
Part of the linkgit:git[1] suite