Merge "Fix typos in ADB documentation"

- keep track of all Android devices and emulators instances

  connected to or running on a given host developer machine

- implement various control commands (e.g. "adb shell", "adb pull", etc..)

- implement various control commands (e.g. "adb shell", "adb pull", etc.)

  for the benefit of clients (command-line users, or helper programs like

  DDMS). These commands are what is called a 'service' in ADB.

  DDMS). These commands are called 'services' in ADB.

As a whole, everything works through the following components:

  1. The ADB server

    This is a background process that runs on the host machine. Its purpose

    if to sense the USB ports to know when devices are attached/removed,

    is to sense the USB ports to know when devices are attached/removed,

    as well as when emulator instances start/stop.

    It thus maintains a list of "connected devices" and assigns a 'state'

    meaning that the ADB server detected a new device/emulator, but could not

    connect to the adbd daemon.

    the BOOTLOADER and RECOVERY states correspond to alternate states of

    The BOOTLOADER and RECOVERY states correspond to alternate states of

    devices when they are in the bootloader or recovery mode.

  3. The ADB command-line client

    or a script. It first tries to locate the ADB server on the host machine,

    and will start one automatically if none is found.

    then, the client sends its service requests to the ADB server. It doesn't

    need to know.

    Then, the client sends its service requests to the ADB server.

    Currently, a single 'adb' binary is used for both the server and client.

    this makes distribution and starting the server easier.

    There are essentially two kinds of services that a client can talk to.

    Host Services:

      these services run within the ADB Server and thus do not need to

      These services run within the ADB Server and thus do not need to

      communicate with a device at all. A typical example is "adb devices"

      which is used to return the list of currently known devices and their

      state. They are a few couple other services though.

      states. They are a few other services though.

    Local Services:

      these services either run within the adbd daemon, or are started by

      These services either run within the adbd daemon, or are started by

      it on the device. The ADB server is used to multiplex streams

      between the client and the service running in adbd. In this case

      its role is to initiate the connection, then of being a pass-through

This file tries to document file related requests a client can make

This file tries to document file-related requests a client can make

to the ADB server of an adbd daemon. See the OVERVIEW.TXT document

to understand what's going on here. See the SERVICES.TXT to learn more

about the other requests that are possible.

Requesting the sync service ("sync:") using the protocol as described in

SERVICES.TXT sets the connection in sync mode. This mode is a binary mode that

differ from the regular adb protocol. The connection stays in sync mode until

differs from the regular adb protocol. The connection stays in sync mode until

explicitly terminated (see below).

After the initial "sync:" command is sent the server must respond with either

"OKAY" or "FAIL" as per usual.

In sync mode both the server and the client will frequently use eight-byte

packets to communicate in this document called sync request and sync

responses. The first four bytes is an id and specifies sync request is

represented by four utf-8 characters. The last four bytes is a Little-Endian

packets to communicate. In this document these are called sync requests and sync

responses. The first four bytes are an id that specifies the sync request. It is

represented by four utf-8 characters. The last four bytes are a Little-Endian

integer, with various uses. This number will be called "length" below. In fact

all binary integers are Little-Endian in the sync mode. Sync mode is

implicitly exited after each sync request, and normal adb communication

SEND - Send a file to device

STAT - Stat a file

For all of the sync request above the must be followed by length number of

bytes containing an utf-8 string with a remote filename.

All of the sync requests above must be followed by "length": the number of

bytes containing a utf-8 string with a remote filename.

LIST:

Lists files in the directory specified by the remote filename. The server will

6. length number of bytes containing an utf-8 string representing the file

   name.

When an sync response "DONE" is received the listing is done.

When a sync response "DONE" is received the listing is done.

SEND:

The remote file name is split into two parts separated by the last

When the file is transferred a sync request "DONE" is sent, where length is set

to the last modified time for the file. The server responds to this last

request (but not to chuck requests) with an "OKAY" sync response (length can

request (but not to chunk requests) with an "OKAY" sync response (length can

be ignored).

Retrieves a file from device to a local file. The remote path is the path to

the file that will be returned. Just as for the SEND sync request the file

received is split up into chunks. The sync response id is "DATA" and length is

the chuck size. After follows chunk size number of bytes. This is repeated

until the file is transferred. Each chuck will not be larger than 64k.

the chunk size. After follows chunk size number of bytes. This is repeated

until the file is transferred. Each chunk will not be larger than 64k.

When the file is transferred a sync response "DONE" is retrieved where the

length can be ignored.