Updates remote refs using local refs, while sending objects necessary to complete the given refs.

You can make interesting things happen to a repository every time you push into it, by setting up hooks there. See documentation for git-receive-pack(1).

The <src> is often the name of the branch you would want to push, but it can be any arbitrary "SHA-1 expression", such as master~4 or HEAD(see gitrevisions(7)).

The <dst> tells which ref on the remote side is updated with this push. Arbitrary expressions cannot be used here, an actual ref must be named. If :<dst> is omitted, the same ref as <src> will be updated.

The object referenced by <src> is used to update the <dst> reference on the remote side, but by default this is only allowed if the update can fast-forward <dst>. By having the optional leading +, you can tell git to update the <dst> ref even when the update is not a fast-forward. This does not attempt to merge <src> into <dst>. See EXAMPLES below for details.

tag <tag> means the same as refs/tags/<tag>:refs/tags/<tag>.

Pushing an empty <src> allows you to delete the <dst> ref from the remote repository.

The special refspec : (or +: to allow non-fast-forward updates) directs git to push "matching" branches: for every branch that exists on the local side, the remote side is updated if a branch of the same name already exists on the remote side. This is the default operation mode if no explicit refspec is found (that is neither on the command line nor in any Push line of the corresponding remotes file---see below).

git push public         #1 git push --repo=public  #2

is that #1 always pushes to "public" whereas #2 pushes to "public" only if the current branch does not track a remote branch. This is useful if you write an alias or script around git push.

In general, URLs contain information about the transport protocol, the address of the remote server, and the path to the repository. Depending on the transport protocol, some of this information may be absent.

Git natively supports ssh, git, http, https, ftp, ftps, and rsync protocols. The following syntaxes may be used with them:

• ssh://[user@]host.xz[:port]/path/to/repo.git/

• git://host.xz[:port]/path/to/repo.git/

• http[s]://host.xz[:port]/path/to/repo.git/

• ftp[s]://host.xz[:port]/path/to/repo.git/

• rsync://host.xz/path/to/repo.git/

An alternative scp-like syntax may also be used with the ssh protocol:

• [user@]host.xz:path/to/repo.git/

The ssh and git protocols additionally support ~username expansion:

• ssh://[user@]host.xz[:port]/~[user]/path/to/repo.git/

• git://host.xz[:port]/~[user]/path/to/repo.git/

• [user@]host.xz:/~[user]/path/to/repo.git/

For local repositories, also supported by git natively, the following syntaxes may be used:

• /path/to/repo.git/

• file:///path/to/repo.git/

These two syntaxes are mostly equivalent, except when cloning, when the former implies --local option. See git-clone(1) for details.

When git doesn’t know how to handle a certain transport protocol, it attempts to use the remote-<transport> remote helper, if one exists. To explicitly request a remote helper, the following syntax may be used:

• <transport>::<address>

where <address> may be a path, a server and path, or an arbitrary URL-like string recognized by the specific remote helper being invoked. Seegit-remote-helpers(1) for details.

If there are a large number of similarly-named remote repositories and you want to use a different format for them (such that the URLs you use will be rewritten into URLs that work), you can create a configuration section of the form:

        [url "<actual url base>"]                 insteadOf = <other url base>

For example, with this:

        [url "git://git.host.xz/"]                 insteadOf = host.xz:/path/to/                 insteadOf = work:

a URL like "work:repo.git" or like "host.xz:/path/to/repo.git" will be rewritten in any context that takes a URL to be "git://git.host.xz/repo.git".

If you want to rewrite URLs for push only, you can create a configuration section of the form:

        [url "<actual url base>"]                 pushInsteadOf = <other url base>

For example, with this:

        [url "ssh://example.org/"]                 pushInsteadOf = git://example.org/

a URL like "git://example.org/path/to/repo.git" will be rewritten to "ssh://example.org/path/to/repo.git" for pushes, but pulls will still use the original URL.

The name of one of the following can be used instead of a URL as <repository> argument:

• a remote in the git configuration file: $GIT_DIR/config,

• a file in the $GIT_DIR/remotes directory, or

• a file in the $GIT_DIR/branches directory.

All of these also allow you to omit the refspec from the command line because they each contain a refspec which git will use by default.

You can choose to provide the name of a remote which you had previously configured using git-remote(1), git-config(1) or even by a manual edit to the $GIT_DIR/config file. The URL of this remote will be used to access the repository. The refspec of this remote will be used by default when you do not provide a refspec on the command line. The entry in the config file would appear like this:

        [remote "<name>"]                 url = <url>                 pushurl = <pushurl>                 push = <refspec>                 fetch = <refspec>

The <pushurl> is used for pushes only. It is optional and defaults to <url>.

You can choose to provide the name of a file in $GIT_DIR/remotes. The URL in this file will be used to access the repository. The refspec in this file will be used as default when you do not provide a refspec on the command line. This file should have the following format:

        URL: one of the above URL format         Push: <refspec>         Pull: <refspec>

Push: lines are used by git push and Pull: lines are used by git pull and git fetch. Multiple Push: and Pull: lines may be specified for additional branch mappings.

You can choose to provide the name of a file in $GIT_DIR/branches. The URL in this file will be used to access the repository. This file should have the following format:

        <url>#<head>

<url> is required; #<head> is optional.

Depending on the operation, git will use one of the following refspecs, if you don’t provide one on the command line. <branch> is the name of this file in $GIT_DIR/branches and <head> defaults to master.

git fetch uses:

        refs/heads/<head>:refs/heads/<branch>

git push uses:

        HEAD:refs/heads/<head>

The output of "git push" depends on the transport method used; this section describes the output when pushing over the git protocol (either locally or via ssh).

The status of the push is output in tabular form, with each line representing the status of a single ref. Each line is of the form:

 <flag> <summary> <from> -> <to> (<reason>)

If --porcelain is used, then each line of the output is of the form:

 <flag> \t <from>:<to> \t <summary> (<reason>)

The status of up-to-date refs is shown only if --porcelain or --verbose option is used.

flag

A single character indicating the status of the ref:

summary

For a successfully pushed ref, the summary shows the old and new values of the ref in a form suitable for using as an argument to git log(this is <old>..<new> in most cases, and <old>...<new> for forced non-fast-forward updates).

from

The name of the local ref being pushed, minus its refs/<type>/ prefix. In the case of deletion, the name of the local ref is omitted.

to

The name of the remote ref being updated, minus its refs/<type>/ prefix.

reason

A human-readable explanation. In the case of successfully pushed refs, no explanation is needed. For a failed ref, the reason for failure is described.

When an update changes a branch (or more in general, a ref) that used to point at commit A to point at another commit B, it is called a fast-forward update if and only if B is a descendant of A.

In a fast-forward update from A to B, the set of commits that the original commit A built on top of is a subset of the commits the new commit B builds on top of. Hence, it does not lose any history.

In contrast, a non-fast-forward update will lose history. For example, suppose you and somebody else started at the same commit X, and you built a history leading to commit B while the other person built a history leading to commit A. The history looks like this:

B

/

---X---A

Further suppose that the other person already pushed changes leading to A back to the original repository you two obtained the original commit X.

The push done by the other person updated the branch that used to point at commit X to point at commit A. It is a fast-forward.

But if you try to push, you will attempt to update the branch (that now points at A) with commit B. This does not fast-forward. If you did so, the changes introduced by commit A will be lost, because everybody will now start building on top of B.

The command by default does not allow an update that is not a fast-forward to prevent such loss of history.

If you do not want to lose your work (history from X to B) nor the work by the other person (history from X to A), you would need to first fetch the history from the repository, create a history that contains changes done by both parties, and push the result back.

You can perform "git pull", resolve potential conflicts, and "git push" the result. A "git pull" will create a merge commit C between commits A and B.

B---C

/   /

---X---A

Updating A with the resulting merge commit will fast-forward and your push will be accepted.

Alternatively, you can rebase your change between X and B on top of A, with "git pull --rebase", and push the result back. The rebase will create a new commit D that builds the change between X and B on top of A.

B   D

/   /

---X---A

Again, updating A with this commit will fast-forward and your push will be accepted.

There is another common situation where you may encounter non-fast-forward rejection when you try to push, and it is possible even when you are pushing into a repository nobody else pushes into. After you push commit A yourself (in the first picture in this section), replace it with "git commit --amend" to produce commit B, and you try to push it out, because forgot that you have pushed A out already. In such a case, and only if you are certain that nobody in the meantime fetched your earlier commit A (and started building on top of it), you can run "git push --force" to overwrite it. In other words, "git push --force" is a method reserved for a case where you do mean to lose history.

The default behavior of this command when no <refspec> is given can be configured by setting the push option of the remote.

For example, to default to pushing only the current branch to origin use git config remote.origin.push HEAD. Any valid <refspec> (like the ones in the examples below) can be configured as the default for git push origin.

The above command would change the origin repository to

A---B  (unnamed branch)

/

o---o---o---X---Y---Z  master

Commits A and B would no longer belong to a branch with a symbolic name, and so would be unreachable. As such, these commits would be removed by a git gc command on the origin repository.