git-remote-helpers
(1)
Name
git-remote-helpers - Helper programs to interact with remote
repositories
Synopsis
git remote-<transport> <repository> [<URL>]
Description
Git Manual GIT-REMOTE-HELPERS(1)
NAME
git-remote-helpers - Helper programs to interact with remote
repositories
SYNOPSIS
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.
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, and update the local
object store.
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.
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.
The command stream is terminated by a blank line. In some
cases (indicated in the documentation of the relevant
commands), this blank line is followed by a payload in some
other protocol (e.g., the pack protocol), while in others it
indicates the end of input.
Capabilities
Each remote helper is expected to support only a subset of
commands. The operations a helper supports are declared to
Git 1.7.9.2 Last change: 02/22/2012 1
Git Manual GIT-REMOTE-HELPERS(1)
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
*:*.
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 1.7.9.2 Last change: 02/22/2012 2
Git Manual GIT-REMOTE-HELPERS(1)
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.
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).
Capabilities for Fetching
connect
Can 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.
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.
Other frontends may have some other order of preference.
refspec <refspec>
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
Git 1.7.9.2 Last change: 02/22/2012 3
Git Manual GIT-REMOTE-HELPERS(1)
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.
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
Commands are given by the caller on the helper's standard
input, one per line.
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).
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
Git 1.7.9.2 Last change: 02/22/2012 4
Git Manual GIT-REMOTE-HELPERS(1)
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 +).
push refs/heads/master:refs/heads/master
push HEAD:refs/heads/branch
\n
push +refs/heads/foo:refs/heads/bar
\n
Git 1.7.9.2 Last change: 02/22/2012 5
Git Manual GIT-REMOTE-HELPERS(1)
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.
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.
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 completing a valid response for the
current command.
Git 1.7.9.2 Last change: 02/22/2012 6
Git Manual GIT-REMOTE-HELPERS(1)
Additional commands may be supported, as may be determined
from capabilities reported by the helper.
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.
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.
Git 1.7.9.2 Last change: 02/22/2012 7
Git Manual GIT-REMOTE-HELPERS(1)
ATTRIBUTES
See attributes(5) for descriptions of the following
attributes:
+---------------+--------------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+--------------------------+
|Availability | developer/versioning/git |
+---------------+--------------------------+
|Stability | Uncommitted |
+---------------+--------------------------+
SEE ALSO
git-remote(1)
git-remote-testgit(1)
GIT
Part of the git(1) suite
NOTES
This software was built from source available at
https://java.net/projects/solaris-userland. The original
community source was downloaded from http://git-
core.googlecode.com/files/git-1.7.9.2.tar.gz
Further information about this software can be found on the
open source community website at http://git-scm.com/.
Git 1.7.9.2 Last change: 02/22/2012 8