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GIT-REMOTE-HELPERS(1) | Git Manual | GIT-REMOTE-HELPERS(1) |
NAME¶
git-remote-helpers - Helper programs to interact with remote repositoriesSYNOPSIS¶
git remote-<transport> <repository> [<URL>]
DESCRIPTION¶
Remote helper programs are normally not used directly by end users, but they are invoked by git when it needs to interact with remote repositories git does not support natively. A given helper will implement a subset of the capabilities documented here. When git needs to interact with a repository using a remote helper, it spawns the helper as an independent process, sends commands to the helper’s standard input, and expects results from the helper’s standard output. Because a remote helper runs as an independent process from git, there is no need to re-link git to add a new helper, nor any need to link the helper with the implementation of git.INPUT FORMAT¶
Git sends the remote helper a list of commands on standard input, one per line. The first command is always the capabilities command, in response to which the remote helper must print a list of the capabilities it supports (see below) followed by a blank line. The response to the capabilities command determines what commands Git uses in the remainder of the command stream.Capabilities¶
Each remote helper is expected to support only a subset of commands. The operations a helper supports are declared to git in the response to the capabilities command (see COMMANDS, below). optionFor specifying settings like verbosity (how
much output to write to stderr) and depth (how much history is wanted in the
case of a shallow clone) that affect how other commands are carried out.
connect
For fetching and pushing using git’s
native packfile protocol that requires a bidirectional, full-duplex
connection.
push
For listing remote refs and pushing specified
objects from the local object store to remote refs.
fetch
For listing remote refs and fetching the
associated history to the local object store.
import
For listing remote refs and fetching the
associated history as a fast-import stream.
refspec <refspec>
This modifies the import capability,
allowing the produced fast-import stream to modify refs in a private namespace
instead of writing to refs/heads or refs/remotes directly. It is recommended
that all importers providing the import capability use this.
A helper advertising the capability refspec
refs/heads/*:refs/svn/origin/branches/* is saying that, when it is asked to
import refs/heads/topic, the stream it outputs will update the
refs/svn/origin/branches/topic ref.
This capability can be advertised multiple times. The first applicable refspec
takes precedence. The left-hand of refspecs advertised with this capability
must cover all refs reported by the list command. If no refspec
capability is advertised, there is an implied refspec *:*.
Capabilities for Pushing¶
connectCan attempt to connect to git
receive-pack (for pushing), git upload-pack, etc for communication
using the packfile protocol.
Supported commands: connect.
push
Can discover remote refs and push local
commits and the history leading up to them to new or existing remote refs.
Supported commands: list for-push, push.
Capabilities for Fetching¶
connectCan try to connect to git upload-pack
(for fetching), git receive-pack, etc for communication using the
packfile protocol.
Supported commands: connect.
fetch
Can discover remote refs and transfer objects
reachable from them to the local object store.
Supported commands: list, fetch.
import
Can discover remote refs and output objects
reachable from them as a stream in fast-import format.
Supported commands: list, import.
This modifies the import capability.
A helper advertising refspec refs/heads/*:refs/svn/origin/branches/* in its
capabilities is saying that, when it handles import refs/heads/topic, the
stream it outputs will update the refs/svn/origin/branches/topic ref.
This capability can be advertised multiple times. The first applicable refspec
takes precedence. The left-hand of refspecs advertised with this capability
must cover all refs reported by the list command. If no refspec
capability is advertised, there is an implied refspec *:*.
INVOCATION¶
Remote helper programs are invoked with one or (optionally) two arguments. The first argument specifies a remote repository as in git; it is either the name of a configured remote or a URL. The second argument specifies a URL; it is usually of the form <transport>://<address>, but any arbitrary string is possible. The GIT_DIR environment variable is set up for the remote helper and can be used to determine where to store additional data or from which directory to invoke auxiliary git commands.COMMANDS¶
Commands are given by the caller on the helper’s standard input, one per line. capabilitiesLists the capabilities of the helper, one per
line, ending with a blank line. Each capability may be preceded with *,
which marks them mandatory for git version using the remote helper to
understand (unknown mandatory capability is fatal error).
list
Lists the refs, one per line, in the format
"<value> <name> [<attr> ...]". The value may be a
hex sha1 hash, "@<dest>" for a symref, or "?" to
indicate that the helper could not get the value of the ref. A space-separated
list of attributes follows the name; unrecognized attributes are ignored. The
list ends with a blank line.
If push is supported this may be called as list for-push to obtain
the current refs prior to sending one or more push commands to the
helper.
option <name> <value>
Sets the transport helper option <name>
to <value>. Outputs a single line containing one of ok (option
successfully set), unsupported (option not recognized) or error
<msg> (option <name> is supported but <value> is not
valid for it). Options should be set before other commands, and may influence
the behavior of those commands.
Supported if the helper has the "option" capability.
fetch <sha1> <name>
Fetches the given object, writing the
necessary objects to the database. Fetch commands are sent in a batch, one per
line, terminated with a blank line. Outputs a single blank line when all fetch
commands in the same batch are complete. Only objects which were reported in
the ref list with a sha1 may be fetched this way.
Optionally may output a lock <file> line indicating a file under
GIT_DIR/objects/pack which is keeping a pack until refs can be suitably
updated.
Supported if the helper has the "fetch" capability.
push +<src>:<dst>
Pushes the given local <src> commit or
branch to the remote branch described by <dst>. A batch sequence of one
or more push commands is terminated with a blank line (if there is only
one reference to push, a single push command is followed by a blank
line). For example, the following would be two batches of push, the
first asking the remote-helper to push the local ref master to the
remote ref master and the local HEAD to the remote
branch, and the second asking to push ref foo to ref bar
(forced update requested by the +).
Zero or more protocol options may be entered after the last push command,
before the batch’s terminating blank line.
When the push is complete, outputs one or more ok <dst> or error
<dst> <why>? lines to indicate success or failure of each
pushed ref. The status report output is terminated by a blank line. The option
field <why> may be quoted in a C style string if it contains an LF.
Supported if the helper has the "push" capability.
import <name>
push refs/heads/master:refs/heads/master push HEAD:refs/heads/branch \n push +refs/heads/foo:refs/heads/bar \n
Produces a fast-import stream which imports
the current value of the named ref. It may additionally import other refs as
needed to construct the history efficiently. The script writes to a
helper-specific private namespace. The value of the named ref should be
written to a location in this namespace derived by applying the refspecs from
the "refspec" capability to the name of the ref.
Especially useful for interoperability with a foreign versioning system.
Just like push, a batch sequence of one or more import is
terminated with a blank line. For each batch of import, the remote
helper should produce a fast-import stream terminated by a done
command.
Supported if the helper has the "import" capability.
connect <service>
Connects to given service. Standard input and
standard output of helper are connected to specified service (git prefix is
included in service name so e.g. fetching uses git-upload-pack as
service) on remote side. Valid replies to this command are empty line
(connection established), fallback (no smart transport support, fall
back to dumb transports) and just exiting with error message printed
(can’t connect, don’t bother trying to fall back). After line feed
terminating the positive (empty) response, the output of service starts. After
the connection ends, the remote helper exits.
Supported if the helper has the "connect" capability.
REF LIST ATTRIBUTES¶
for-pushThe caller wants to use the ref list to
prepare push commands. A helper might chose to acquire the ref list by opening
a different type of connection to the destination.
unchanged
This ref is unchanged since the last import or
fetch, although the helper cannot necessarily determine what value that
produced.
OPTIONS¶
option verbosity <n>Changes the verbosity of messages displayed by
the helper. A value of 0 for <n> means that processes operate quietly,
and the helper produces only error output. 1 is the default level of
verbosity, and higher values of <n> correspond to the number of -v flags
passed on the command line.
option progress {true|false}
Enables (or disables) progress messages
displayed by the transport helper during a command.
option depth <depth>
Deepens the history of a shallow
repository.
option followtags {true|false}
If enabled the helper should automatically
fetch annotated tag objects if the object the tag points at was transferred
during the fetch command. If the tag is not fetched by the helper a second
fetch command will usually be sent to ask for the tag specifically. Some
helpers may be able to use this option to avoid a second network
connection.
Sets service path (--upload-pack,
--receive-pack etc.) for next connect. Remote helper may support this option,
but must not rely on this option being set before connect request
occurs.
SEE ALSO¶
git-remote(1)GIT¶
Part of the git(1) suite03/19/2016 | Git 1.7.10.4 |