-----------
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
+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.
+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.
-Every helper must support the "capabilities" command, which git
+Every helper must support the "capabilities" command, which Git
uses to determine what other commands the helper will accept. Those
other commands can be used to discover and update remote refs,
transport objects between the object database and the remote repository,
'git-remote-ftp' and 'git-remote-ftps'. They implement the capabilities
'fetch', 'option', and 'push'.
+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.
+
+When Git encounters a URL of the form '<transport>://<address>', where
+'<transport>' is a protocol that it cannot handle natively, it
+automatically invokes 'git remote-<transport>' with the full URL as
+the second argument. If such a URL is encountered directly on the
+command line, the first argument is the same as the second, and if it
+is encountered in a configured remote, the first argument is the name
+of that remote.
+
+A URL of the form '<transport>::<address>' explicitly instructs Git to
+invoke 'git remote-<transport>' with '<address>' as the second
+argument. If such a URL is encountered directly on the command line,
+the first argument is '<address>', and if it is encountered in a
+configured remote, the first argument is the name of that remote.
+
+Additionally, when a configured remote has 'remote.<name>.vcs' set to
+'<transport>', Git explicitly invokes 'git remote-<transport>' with
+'<name>' as the first argument. If set, the second argument is
+'remote.<name>.url'; otherwise, the second argument is omitted.
+
INPUT FORMAT
------------
~~~~~~~~~~~~
Each remote helper is expected to support only a subset of commands.
-The operations a helper supports are declared to git in the response
+The operations a helper supports are declared to Git in the response
to the `capabilities` command (see COMMANDS, below).
-'option'::
- For 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 *:*`.
+In the following, we list all defined capabilities and for
+each we list which commands a helper with that capability
+must provide.
Capabilities for Pushing
-~~~~~~~~~~~~~~~~~~~~~~~~
+^^^^^^^^^^^^^^^^^^^^^^^^
'connect'::
Can attempt to connect to 'git receive-pack' (for pushing),
- 'git upload-pack', etc for communication using the
- packfile protocol.
+ 'git upload-pack', etc for communication using
+ git's native packfile protocol. This
+ requires a bidirectional, full-duplex connection.
+
Supported commands: 'connect'.
+
Supported commands: 'list for-push', 'push'.
-If a helper advertises both 'connect' and 'push', git will use
-'connect' if possible and fall back to 'push' if the helper requests
-so when connecting (see the 'connect' command under COMMANDS).
+'export'::
+ Can discover remote refs and push specified objects from a
+ fast-import stream to remote refs.
++
+Supported commands: 'list for-push', 'export'.
+
+If a helper advertises 'connect', Git will use it if possible and
+fall back to another capability if the helper requests so when
+connecting (see the 'connect' command under COMMANDS).
+When choosing between 'push' and 'export', Git prefers 'push'.
+Other frontends may have some other order of preference.
+
Capabilities for Fetching
-~~~~~~~~~~~~~~~~~~~~~~~~~
+^^^^^^^^^^^^^^^^^^^^^^^^^
'connect'::
Can try to connect to 'git upload-pack' (for fetching),
'git receive-pack', etc for communication using the
- packfile protocol.
+ Git's native packfile protocol. This
+ requires a bidirectional, full-duplex connection.
+
Supported commands: 'connect'.
+
Supported commands: 'list', 'import'.
-If a helper advertises 'connect', git will use it if possible and
+If a helper advertises 'connect', Git will use it if possible and
fall back to another capability if the helper requests so when
connecting (see the 'connect' command under COMMANDS).
-When choosing between 'fetch' and 'import', git prefers 'fetch'.
+When choosing between 'fetch' and 'import', Git prefers 'fetch'.
Other frontends may have some other order of preference.
+Miscellaneous capabilities
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+'option'::
+ For 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.
+
'refspec' <refspec>::
- This modifies the 'import' capability.
+ 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
+A helper advertising the capability
`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.
+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
the list command. If no 'refspec' capability is advertised,
there is an implied `refspec *:*`.
-INVOCATION
-----------
+'bidi-import'::
+ This modifies the 'import' capability.
+ The fast-import commands 'cat-blob' and 'ls' can be used by remote-helpers
+ to retrieve information about blobs and trees that already exist in
+ fast-import's memory. This requires a channel from fast-import to the
+ remote-helper.
+ If it is advertised in addition to "import", Git establishes a pipe from
+ fast-import to the remote-helper's stdin.
+ It follows that Git and fast-import are both connected to the
+ remote-helper's stdin. Because Git can send multiple commands to
+ the remote-helper it is required that helpers that use 'bidi-import'
+ buffer all 'import' commands of a batch before sending data to fast-import.
+ This is to prevent mixing commands and fast-import responses on the
+ helper's stdin.
-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.
+'export-marks' <file>::
+ This modifies the 'export' capability, instructing Git to dump the
+ internal marks table to <file> when complete. For details,
+ read up on '--export-marks=<file>' in linkgit:git-fast-export[1].
+
+'import-marks' <file>::
+ This modifies the 'export' capability, instructing Git to load the
+ marks specified in <file> before processing any input. For details,
+ read up on '--import-marks=<file>' in linkgit:git-fast-export[1].
-When git encounters a URL of the form '<transport>://<address>', where
-'<transport>' is a protocol that it cannot handle natively, it
-automatically invokes 'git remote-<transport>' with the full URL as
-the second argument. If such a URL is encountered directly on the
-command line, the first argument is the same as the second, and if it
-is encountered in a configured remote, the first argument is the name
-of that remote.
-A URL of the form '<transport>::<address>' explicitly instructs git to
-invoke 'git remote-<transport>' with '<address>' as the second
-argument. If such a URL is encountered directly on the command line,
-the first argument is '<address>', and if it is encountered in a
-configured remote, the first argument is the name of that remote.
-Additionally, when a configured remote has 'remote.<name>.vcs' set to
-'<transport>', git explicitly invokes 'git remote-<transport>' with
-'<name>' as the first argument. If set, the second argument is
-'remote.<name>.url'; otherwise, the second argument is omitted.
COMMANDS
--------
'capabilities'::
Lists 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).
+ which marks them mandatory for Git versions using the remote
+ helper to understand. Any unknown mandatory capability is a
+ fatal error.
++
+Support for this command is mandatory.
'list'::
Lists the refs, one per line, in the format "<value> <name>
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.
+See REF LIST ATTRIBUTES for a list of currently defined attributes.
++
+Supported if the helper has the "fetch" or "import" capability.
+
+'list for-push'::
+ Similar to 'list', except that it is used if and only if
+ the caller wants to the resulting ref list to prepare
+ push commands.
+ A helper supporting both push and fetch can use this
+ to distinguish for which operation the output of 'list'
+ is going to be used, possibly reducing the amount
+ of work that needs to be performed.
++
+Supported if the helper has the "push" or "export" capability.
'option' <name> <value>::
Sets the transport helper option <name> to <value>. Outputs a
for it). Options should be set before other commands,
and may influence the behavior of those commands.
+
+See OPTIONS for a list of currently defined options.
++
Supported if the helper has the "option" capability.
'fetch' <sha1> <name>::
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.
+ in the output of '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
helper should produce a fast-import stream terminated by a 'done'
command.
+
+Note that if the 'bidi-import' capability is used the complete batch
+sequence has to be buffered before starting to send data to fast-import
+to prevent mixing of commands and fast-import responses on the helper's
+stdin.
++
Supported if the helper has the "import" capability.
+'export'::
+ Instructs the remote helper that any subsequent input is
+ part of a fast-import stream (generated by 'git fast-export')
+ containing objects which should be pushed to the remote.
++
+Especially useful for interoperability with a foreign versioning
+system.
++
+The 'export-marks' and 'import-marks' capabilities, if specified,
+affect this command in so far as they are passed on to 'git
+fast-export', which then will load/store a table of marks for
+local objects. This can be used to implement for incremental
+operations.
++
+Supported if the helper has the "export" capability.
+
'connect' <service>::
Connects to given service. Standard input and standard output
of helper are connected to specified service (git prefix is
REF LIST ATTRIBUTES
-------------------
-'for-push'::
- The 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.
+The 'list' command produces a list of refs in which each ref
+may be followed by a list of attributes. The following ref list
+attributes are defined.
'unchanged'::
This ref is unchanged since the last import or fetch, although
OPTIONS
-------
+
+The following options are defined and (under suitable circumstances)
+set by Git if the remote helper has the 'option' capability.
+
'option verbosity' <n>::
Changes the verbosity of messages displayed by the helper.
A value of 0 for <n> means that processes operate