NAME
----
-git-remote-helpers - Helper programs for interoperation with remote git
+git-remote-helpers - Helper programs to interact with remote repositories
SYNOPSIS
--------
-'git remote-<transport>' <remote>
+'git remote-<transport>' <repository> [<URL>]
DESCRIPTION
-----------
-These programs are normally not used directly by end users, but are
-invoked by various git programs that interact with remote repositories
-when the repository they would operate on will be accessed using
-transport code not linked into the main git binary. Various particular
-helper programs will behave as documented here.
+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.
+
+Every helper must support the "capabilities" command, which git will
+use to determine what other commands the helper will accept. Other
+commands generally concern facilities like discovering and updating
+remote refs, transporting objects between the object database and
+the remote repository, and updating the local object store.
+
+Helpers supporting the 'fetch' capability can discover refs from the
+remote repository and transfer objects reachable from those refs to
+the local object store. Helpers supporting the 'push' capability can
+transfer local objects to the remote repository and update remote refs.
+
+Git comes with a "curl" family of remote helpers, that handle various
+transport protocols, such as 'git-remote-http', 'git-remote-https',
+'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.
+
+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.
+ 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. After the
- complete list, outputs a blank line.
+ 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. Outputs a blank line when the fetch is
- complete. Only objects which were reported in the ref list
- with a sha1 may be fetched this way.
+ 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.
++
+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>::
+ 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.
++
+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.
+
If a fatal error occurs, the program writes the error message to
stderr and exits. The caller should expect that a suitable error
message has been printed if the child closes the connection without
------------
'fetch'::
- This helper supports the 'fetch' command.
+'option'::
+'push'::
+'import'::
+'connect'::
+ This helper supports the corresponding command with the same name.
+
+'refspec' 'spec'::
+ When using the import command, expect the source ref to have
+ been written to the destination ref. The earliest applicable
+ refspec takes precedence. For example
+ "refs/heads/*:refs/svn/origin/branches/*" means that, after an
+ "import refs/heads/name", the script has written to
+ refs/svn/origin/branches/name. If this capability is used at
+ all, it must cover all refs reported by the list command; if
+ it is not used, it is effectively "*:*"
REF LIST ATTRIBUTES
-------------------
-None are defined yet, but the caller must accept any which are supplied.
-
-Documentation
--------------
-Documentation by Daniel Barkalow.
+'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.
+
+'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.
+
+'option dry-run' \{'true'|'false'\}:
+ If true, pretend the operation completed successfully,
+ but don't actually change any repository data. For most
+ helpers this only applies to the 'push', if supported.
+
+'option servpath <c-style-quoted-path>'::
+ 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
+--------
+linkgit:git-remote[1]
GIT
---