..
 #############################################################
 # This file was automatically generated on 2015-05-08.      #
 #                                                           #
 # If you have a bugfix for this file and want to commit it, #
 # please fix the bug in the generator. You can find a link  #
 # to the generators git repository on tinkerforge.com       #
 #############################################################


:breadcrumbs: <a href="../../index.html">Home</a> / <a href="../../index.html#software-php">Software</a> / PHP - RED Brick

.. |device_identifier_constant| replace:: There is also a :ref:`constant <red_brick_php_constants>` for the device identifier of this Brick.

.. _red_brick_php:

PHP - RED Brick
===============

This is the description of the :ref:`PHP API bindings <api_bindings_php>` for the :ref:`RED Brick <red_brick>`. General information and technical
specifications for the RED Brick are summarized in its :ref:`hardware description
<red_brick_description>`.

An :ref:`installation guide <api_bindings_php_install>` for the PHP API
bindings is part of their general description.

.. _red_brick_php_examples:


Examples
--------

The example code below is `Public Domain (CC0 1.0)
<http://creativecommons.org/publicdomain/zero/1.0/>`__.

.. _red_brick_php_api:

API
---

Functions that return multiple values return them in an associative array.


The RED Brick API is meant to be used by the Brick Viewer to implement the
offered  functionality (getting status information, managing programs etc.).
Normal users will not need to use this API, it may only be interesting for
power users.

FIXME: explain sessions

The RED Brick API operates on reference counted objects (strings, lists, files,
directories, processes and programs) that are identified by their 16bit object
ID. Functions that allocate or return an object ID (e.g. :php:func:`allocateString() <BrickRED::allocateString>`
and :php:func:`getNextDirectoryEntry() <BrickRED::getNextDirectoryEntry>`) increase the reference count of the returned
object. If the object is no longer needed then :php:func:`releaseObject() <BrickRED::releaseObject>` has to
be called to decrease the reference count of the object again. In contrast to
allocation and getter functions, the reference count for an object returned by
a callback is not increased and :php:func:`releaseObject() <BrickRED::releaseObject>` must not be called for
such an object in response to a callback.

There are functions (e.g. :php:func:`getFileInfo() <BrickRED::getFileInfo>`) that only return valid objects
under certain conditions. This conditions are documented for the specific
functions. For invalid objects :php:func:`releaseObject() <BrickRED::releaseObject>` must not be called.

There are also function (e.g. :php:func:`setProgramStdioRedirection() <BrickRED::setProgramStdioRedirection>`) that have
conditionally unused object parameters. Under which conditions an object
parameter is unused is documented for the specific functions. For unused
object parameters 0 has to be passed as object ID.

The RED Brick API is more complex then the typical Brick API and requires more
elaborate error reporting than the :ref:`TCP/IP protocol <llproto_tcpip>`
can provide with its 2bit error code. Therefore, almost all functions of the
RED Brick API return an 8bit error code. Possible error codes are:

* Success = 0
* UnknownError = 1
* InvalidOperation = 2
* OperationAborted = 3
* InternalError = 4
* UnknownSessionID = 5
* NoFreeSessionID = 6
* UnknownObjectID = 7
* NoFreeObjectID = 8
* ObjectIsLocked = 9
* NoMoreData = 10
* WrongListItemType = 11
* ProgramIsPurged = 12
* InvalidParameter = 128 (EINVAL)
* NoFreeMemory = 129 (ENOMEM)
* NoFreeSpace = 130 (ENOSPC)
* AccessDenied = 131 (EACCES)
* AlreadyExists = 132 (EEXIST)
* DoesNotExist = 133 (ENOENT)
* Interrupted = 134 (EINTR)
* IsDirectory = 135 (EISDIR)
* NotADirectory = 136 (ENOTDIR)
* WouldBlock = 137 (EWOULDBLOCK)
* Overflow = 138 (EOVERFLOW)
* BadFileDescriptor = 139 (EBADF)
* OutOfRange = 140 (ERANGE)
* NameTooLong = 141 (ENAMETOOLONG)
* InvalidSeek = 142 (ESPIPE)
* NotSupported = 143 (ENOTSUP)
* TooManyOpenFiles = 144 (EMFILE)

If a function returns an error code other than *Success* then its other
return values (if any) are invalid and must not be used.

The error code *InvalidOperation* is returned if the requested operation cannot
be performed because the current state of the object does not allow it. For
example, trying to append an item to a full list object or trying to undefine
an already undefined program.

The error code *NotSupported* is returned if the requested operation can never
be performed. For example, trying to append a list object to itself, trying to
get the name of a file object with type *Pipe* or trying to create a directory
non-recursively with more than the last part of the directory name referring
to non-existing directories.

String objects store UTF-8 encoded data.



Advanced Functions
^^^^^^^^^^^^^^^^^^

.. php:function:: array BrickRED::createSession(int $lifetime)

 
 The returned array has the keys ``error_code`` and ``session_id``.

.. php:function:: int BrickRED::expireSession(int $session_id)

 
.. php:function:: void BrickRED::expireSessionUnchecked(int $session_id)

 
.. php:function:: int BrickRED::keepSessionAlive(int $session_id, int $lifetime)

 
.. php:function:: int BrickRED::releaseObject(int $object_id, int $session_id)

 Decreases the reference count of an object by one and returns the resulting
 error code. If the reference count reaches zero the object gets destroyed.
 
.. php:function:: void BrickRED::releaseObjectUnchecked(int $object_id, int $session_id)

 
.. php:function:: array BrickRED::allocateString(int $length_to_reserve, string $buffer, int $session_id)

 Allocates a new string object, reserves ``length_to_reserve`` bytes memory
 for it and sets up to the first 60 bytes. Set ``length_to_reserve`` to the
 length of the string that should be stored in the string object.
 
 Returns the object ID of the new string object and the resulting error code.
 
 The returned array has the keys ``error_code`` and ``string_id``.

.. php:function:: int BrickRED::truncateString(int $string_id, int $length)

 Truncates a string object to ``length`` bytes and returns the resulting
 error code.
 
.. php:function:: array BrickRED::getStringLength(int $string_id)

 Returns the length of a string object in bytes and the resulting error code.
 
 The returned array has the keys ``error_code`` and ``length``.

.. php:function:: int BrickRED::setStringChunk(int $string_id, int $offset, string $buffer)

 Sets a chunk of up to 58 bytes in a string object beginning at ``offset``.
 
 Returns the resulting error code.
 
.. php:function:: array BrickRED::getStringChunk(int $string_id, int $offset)

 Returns a chunk up to 63 bytes from a string object beginning at ``offset`` and
 returns the resulting error code.
 
 The returned array has the keys ``error_code`` and ``buffer``.

.. php:function:: array BrickRED::allocateList(int $length_to_reserve, int $session_id)

 Allocates a new list object and reserves memory for ``length_to_reserve``
 items. Set ``length_to_reserve`` to the number of items that should be stored
 in the list object.
 
 Returns the object ID of the new list object and the resulting error code.
 
 When a list object gets destroyed then the reference count of each object in
 the list object is decreased by one.
 
 The returned array has the keys ``error_code`` and ``list_id``.

.. php:function:: array BrickRED::getListLength(int $list_id)

 Returns the length of a list object in items and the resulting error code.
 
 The returned array has the keys ``error_code`` and ``length``.

.. php:function:: array BrickRED::getListItem(int $list_id, int $index, int $session_id)

 Returns the object ID and type of the object stored at ``index`` in a list
 object and returns the resulting error code.
 
 Possible object types are:
 
 * String = 0
 * List = 1
 * File = 2
 * Directory = 3
 * Process = 4
 * Program = 5
 
 The following constants are available for this function:
 
 * BrickRED::OBJECT_TYPE_STRING = 0
 * BrickRED::OBJECT_TYPE_LIST = 1
 * BrickRED::OBJECT_TYPE_FILE = 2
 * BrickRED::OBJECT_TYPE_DIRECTORY = 3
 * BrickRED::OBJECT_TYPE_PROCESS = 4
 * BrickRED::OBJECT_TYPE_PROGRAM = 5
 
 The returned array has the keys ``error_code``, ``item_object_id`` and ``type``.

.. php:function:: int BrickRED::appendToList(int $list_id, int $item_object_id)

 Appends an object to a list object and increases the reference count of the
 appended object by one.
 
 Returns the resulting error code.
 
.. php:function:: int BrickRED::removeFromList(int $list_id, int $index)

 Removes the object stored at ``index`` from a list object and decreases the
 reference count of the removed object by one.
 
 Returns the resulting error code.
 
.. php:function:: array BrickRED::openFile(int $name_string_id, int $flags, int $permissions, int $uid, int $gid, int $session_id)

 Opens an existing file or creates a new file and allocates a new file object
 for it.
 
 FIXME: name has to be absolute
 
 The reference count of the name string object is increased by one. When the
 file object gets destroyed then the reference count of the name string object is
 decreased by one. Also the name string object is locked and cannot be modified
 while the file object holds a reference to it.
 
 The ``flags`` parameter takes a ORed combination of the following possible file
 flags (in hexadecimal notation):
 
 * ReadOnly = 0x0001 (O_RDONLY)
 * WriteOnly = 0x0002 (O_WRONLY)
 * ReadWrite = 0x0004 (O_RDWR)
 * Append = 0x0008 (O_APPEND)
 * Create = 0x0010 (O_CREAT)
 * Exclusive = 0x0020 (O_EXCL)
 * NonBlocking = 0x0040 (O_NONBLOCK)
 * Truncate = 0x0080 (O_TRUNC)
 * Temporary = 0x0100
 * Replace = 0x0200
 
 FIXME: explain *Temporary* and *Replace* flag
 
 The ``permissions`` parameter takes a ORed combination of the following
 possible file permissions (in octal notation) that match the common UNIX
 permission bits:
 
 * UserRead = 00400
 * UserWrite = 00200
 * UserExecute = 00100
 * GroupRead = 00040
 * GroupWrite = 00020
 * GroupExecute = 00010
 * OthersRead = 00004
 * OthersWrite = 00002
 * OthersExecute = 00001
 
 Returns the object ID of the new file object and the resulting error code.
 
 The following constants are available for this function:
 
 * BrickRED::FILE_FLAG_READ_ONLY = 1
 * BrickRED::FILE_FLAG_WRITE_ONLY = 2
 * BrickRED::FILE_FLAG_READ_WRITE = 4
 * BrickRED::FILE_FLAG_APPEND = 8
 * BrickRED::FILE_FLAG_CREATE = 16
 * BrickRED::FILE_FLAG_EXCLUSIVE = 32
 * BrickRED::FILE_FLAG_NON_BLOCKING = 64
 * BrickRED::FILE_FLAG_TRUNCATE = 128
 * BrickRED::FILE_FLAG_TEMPORARY = 256
 * BrickRED::FILE_FLAG_REPLACE = 512
 * BrickRED::FILE_PERMISSION_USER_ALL = 448
 * BrickRED::FILE_PERMISSION_USER_READ = 256
 * BrickRED::FILE_PERMISSION_USER_WRITE = 128
 * BrickRED::FILE_PERMISSION_USER_EXECUTE = 64
 * BrickRED::FILE_PERMISSION_GROUP_ALL = 56
 * BrickRED::FILE_PERMISSION_GROUP_READ = 32
 * BrickRED::FILE_PERMISSION_GROUP_WRITE = 16
 * BrickRED::FILE_PERMISSION_GROUP_EXECUTE = 8
 * BrickRED::FILE_PERMISSION_OTHERS_ALL = 7
 * BrickRED::FILE_PERMISSION_OTHERS_READ = 4
 * BrickRED::FILE_PERMISSION_OTHERS_WRITE = 2
 * BrickRED::FILE_PERMISSION_OTHERS_EXECUTE = 1
 
 The returned array has the keys ``error_code`` and ``file_id``.

.. php:function:: array BrickRED::createPipe(int $flags, int $length, int $session_id)

 Creates a new pipe and allocates a new file object for it.
 
 The ``flags`` parameter takes a ORed combination of the following possible
 pipe flags (in hexadecimal notation):
 
 * NonBlockingRead = 0x0001
 * NonBlockingWrite = 0x0002
 
 The length of the pipe buffer can be specified with the ``length`` parameter
 in bytes. If length is set to zero, then the default pipe buffer length is used.
 
 Returns the object ID of the new file object and the resulting error code.
 
 The following constants are available for this function:
 
 * BrickRED::PIPE_FLAG_NON_BLOCKING_READ = 1
 * BrickRED::PIPE_FLAG_NON_BLOCKING_WRITE = 2
 
 The returned array has the keys ``error_code`` and ``file_id``.

.. php:function:: array BrickRED::getFileInfo(int $file_id, int $session_id)

 Returns various information about a file and the resulting error code.
 
 Possible file types are:
 
 * Unknown = 0
 * Regular = 1
 * Directory = 2
 * Character = 3
 * Block = 4
 * FIFO = 5
 * Symlink = 6
 * Socket = 7
 * Pipe = 8
 
 If the file type is *Pipe* then the returned name string object is invalid,
 because a pipe has no name. Otherwise the returned name string object was used
 to open or create the file object, as passed to :php:func:`openFile() <BrickRED::openFile>`.
 
 The returned flags were used to open or create the file object, as passed to
 :php:func:`openFile() <BrickRED::openFile>` or :php:func:`createPipe() <BrickRED::createPipe>`. See the respective function for a list
 of possible file and pipe flags.
 
 FIXME: everything except flags and length is invalid if file type is *Pipe*
 
 The following constants are available for this function:
 
 * BrickRED::FILE_TYPE_UNKNOWN = 0
 * BrickRED::FILE_TYPE_REGULAR = 1
 * BrickRED::FILE_TYPE_DIRECTORY = 2
 * BrickRED::FILE_TYPE_CHARACTER = 3
 * BrickRED::FILE_TYPE_BLOCK = 4
 * BrickRED::FILE_TYPE_FIFO = 5
 * BrickRED::FILE_TYPE_SYMLINK = 6
 * BrickRED::FILE_TYPE_SOCKET = 7
 * BrickRED::FILE_TYPE_PIPE = 8
 * BrickRED::FILE_PERMISSION_USER_ALL = 448
 * BrickRED::FILE_PERMISSION_USER_READ = 256
 * BrickRED::FILE_PERMISSION_USER_WRITE = 128
 * BrickRED::FILE_PERMISSION_USER_EXECUTE = 64
 * BrickRED::FILE_PERMISSION_GROUP_ALL = 56
 * BrickRED::FILE_PERMISSION_GROUP_READ = 32
 * BrickRED::FILE_PERMISSION_GROUP_WRITE = 16
 * BrickRED::FILE_PERMISSION_GROUP_EXECUTE = 8
 * BrickRED::FILE_PERMISSION_OTHERS_ALL = 7
 * BrickRED::FILE_PERMISSION_OTHERS_READ = 4
 * BrickRED::FILE_PERMISSION_OTHERS_WRITE = 2
 * BrickRED::FILE_PERMISSION_OTHERS_EXECUTE = 1
 
 The returned array has the keys ``error_code``, ``type``, ``name_string_id``, ``flags``, ``permissions``, ``uid``, ``gid``, ``length``, ``access_timestamp``, ``modification_timestamp`` and ``status_change_timestamp``.

.. php:function:: array BrickRED::readFile(int $file_id, int $length_to_read)

 Reads up to 62 bytes from a file object.
 
 Returns the bytes read, the actual number of bytes read and the resulting
 error code.
 
 If there is not data to be read, either because the file position reached
 end-of-file or because there is not data in the pipe, then zero bytes are
 returned.
 
 If the file object was created by :php:func:`openFile() <BrickRED::openFile>` without the *NonBlocking*
 flag or by :php:func:`createPipe() <BrickRED::createPipe>` without the *NonBlockingRead* flag then the
 error code *NotSupported* is returned.
 
 The returned array has the keys ``error_code``, ``buffer`` and ``length_read``.

.. php:function:: void BrickRED::readFileAsync(int $file_id, int $length_to_read)

 Reads up to 2\ :sup:`63`\  - 1 bytes from a file object asynchronously.
 
 Reports the bytes read (in 60 byte chunks), the actual number of bytes read and
 the resulting error code via the :php:member:`CALLBACK_ASYNC_FILE_READ <BrickRED::CALLBACK_ASYNC_FILE_READ>` callback.
 
 If there is not data to be read, either because the file position reached
 end-of-file or because there is not data in the pipe, then zero bytes are
 reported.
 
 If the file object was created by :php:func:`openFile() <BrickRED::openFile>` without the *NonBlocking*
 flag or by :php:func:`createPipe() <BrickRED::createPipe>` without the *NonBlockingRead* flag then the error
 code *NotSupported* is reported via the :php:member:`CALLBACK_ASYNC_FILE_READ <BrickRED::CALLBACK_ASYNC_FILE_READ>` callback.
 
.. php:function:: int BrickRED::abortAsyncFileRead(int $file_id)

 Aborts a :php:func:`readFileAsync() <BrickRED::readFileAsync>` operation in progress.
 
 Returns the resulting error code.
 
 On success the :php:member:`CALLBACK_ASYNC_FILE_READ <BrickRED::CALLBACK_ASYNC_FILE_READ>` callback will report *OperationAborted*.
 
.. php:function:: array BrickRED::writeFile(int $file_id, array $buffer, int $length_to_write)

 Writes up to 61 bytes to a file object.
 
 Returns the actual number of bytes written and the resulting error code.
 
 If the file object was created by :php:func:`openFile() <BrickRED::openFile>` without the *NonBlocking*
 flag or by :php:func:`createPipe() <BrickRED::createPipe>` without the *NonBlockingWrite* flag then the
 error code *NotSupported* is returned.
 
 The returned array has the keys ``error_code`` and ``length_written``.

.. php:function:: void BrickRED::writeFileUnchecked(int $file_id, array $buffer, int $length_to_write)

 Writes up to 61 bytes to a file object.
 
 Does neither report the actual number of bytes written nor the resulting error
 code.
 
 If the file object was created by :php:func:`openFile() <BrickRED::openFile>` without the *NonBlocking*
 flag or by :php:func:`createPipe() <BrickRED::createPipe>` without the *NonBlockingWrite* flag then the
 write operation will fail silently.
 
.. php:function:: void BrickRED::writeFileAsync(int $file_id, array $buffer, int $length_to_write)

 Writes up to 61 bytes to a file object.
 
 Reports the actual number of bytes written and the resulting error code via the
 :php:member:`CALLBACK_ASYNC_FILE_WRITE <BrickRED::CALLBACK_ASYNC_FILE_WRITE>` callback.
 
 If the file object was created by :php:func:`openFile() <BrickRED::openFile>` without the *NonBlocking*
 flag or by :php:func:`createPipe() <BrickRED::createPipe>` without the *NonBlockingWrite* flag then the
 error code *NotSupported* is reported via the :php:member:`CALLBACK_ASYNC_FILE_WRITE <BrickRED::CALLBACK_ASYNC_FILE_WRITE>` callback.
 
.. php:function:: array BrickRED::setFilePosition(int $file_id, int $offset, int $origin)

 Set the current seek position of a file object in bytes relative to ``origin``.
 
 Possible file origins are:
 
 * Beginning = 0
 * Current = 1
 * End = 2
 
 Returns the resulting absolute seek position and error code.
 
 If the file object was created by :php:func:`createPipe() <BrickRED::createPipe>` then it has no seek
 position and the error code *InvalidSeek* is returned.
 
 The following constants are available for this function:
 
 * BrickRED::FILE_ORIGIN_BEGINNING = 0
 * BrickRED::FILE_ORIGIN_CURRENT = 1
 * BrickRED::FILE_ORIGIN_END = 2
 
 The returned array has the keys ``error_code`` and ``position``.

.. php:function:: array BrickRED::getFilePosition(int $file_id)

 Returns the current seek position of a file object in bytes and returns the
 resulting error code.
 
 If the file object was created by :php:func:`createPipe() <BrickRED::createPipe>` then it has no seek
 position and the error code *InvalidSeek* is returned.
 
 The returned array has the keys ``error_code`` and ``position``.

.. php:function:: int BrickRED::setFileEvents(int $file_id, int $events)

 
 The following constants are available for this function:
 
 * BrickRED::FILE_EVENT_READABLE = 1
 * BrickRED::FILE_EVENT_WRITABLE = 2
 
.. php:function:: array BrickRED::getFileEvents(int $file_id)

 
 The following constants are available for this function:
 
 * BrickRED::FILE_EVENT_READABLE = 1
 * BrickRED::FILE_EVENT_WRITABLE = 2
 
 The returned array has the keys ``error_code`` and ``events``.

.. php:function:: array BrickRED::openDirectory(int $name_string_id, int $session_id)

 Opens an existing directory and allocates a new directory object for it.
 
 FIXME: name has to be absolute
 
 The reference count of the name string object is increased by one. When the
 directory object is destroyed then the reference count of the name string
 object is decreased by one. Also the name string object is locked and cannot be
 modified while the directory object holds a reference to it.
 
 Returns the object ID of the new directory object and the resulting error code.
 
 The returned array has the keys ``error_code`` and ``directory_id``.

.. php:function:: array BrickRED::getDirectoryName(int $directory_id, int $session_id)

 Returns the name of a directory object, as passed to :php:func:`openDirectory() <BrickRED::openDirectory>`, and
 the resulting error code.
 
 The returned array has the keys ``error_code`` and ``name_string_id``.

.. php:function:: array BrickRED::getNextDirectoryEntry(int $directory_id, int $session_id)

 Returns the next entry in a directory object and the resulting error code.
 
 If there is not next entry then error code *NoMoreData* is returned. To rewind
 a directory object call :php:func:`rewindDirectory() <BrickRED::rewindDirectory>`.
 
 Possible directory entry types are:
 
 * Unknown = 0
 * Regular = 1
 * Directory = 2
 * Character = 3
 * Block = 4
 * FIFO = 5
 * Symlink = 6
 * Socket = 7
 
 The following constants are available for this function:
 
 * BrickRED::DIRECTORY_ENTRY_TYPE_UNKNOWN = 0
 * BrickRED::DIRECTORY_ENTRY_TYPE_REGULAR = 1
 * BrickRED::DIRECTORY_ENTRY_TYPE_DIRECTORY = 2
 * BrickRED::DIRECTORY_ENTRY_TYPE_CHARACTER = 3
 * BrickRED::DIRECTORY_ENTRY_TYPE_BLOCK = 4
 * BrickRED::DIRECTORY_ENTRY_TYPE_FIFO = 5
 * BrickRED::DIRECTORY_ENTRY_TYPE_SYMLINK = 6
 * BrickRED::DIRECTORY_ENTRY_TYPE_SOCKET = 7
 
 The returned array has the keys ``error_code``, ``name_string_id`` and ``type``.

.. php:function:: int BrickRED::rewindDirectory(int $directory_id)

 Rewinds a directory object and returns the resulting error code.
 
.. php:function:: int BrickRED::createDirectory(int $name_string_id, int $flags, int $permissions, int $uid, int $gid)

 FIXME: name has to be absolute
 
 The following constants are available for this function:
 
 * BrickRED::DIRECTORY_FLAG_RECURSIVE = 1
 * BrickRED::DIRECTORY_FLAG_EXCLUSIVE = 2
 * BrickRED::FILE_PERMISSION_USER_ALL = 448
 * BrickRED::FILE_PERMISSION_USER_READ = 256
 * BrickRED::FILE_PERMISSION_USER_WRITE = 128
 * BrickRED::FILE_PERMISSION_USER_EXECUTE = 64
 * BrickRED::FILE_PERMISSION_GROUP_ALL = 56
 * BrickRED::FILE_PERMISSION_GROUP_READ = 32
 * BrickRED::FILE_PERMISSION_GROUP_WRITE = 16
 * BrickRED::FILE_PERMISSION_GROUP_EXECUTE = 8
 * BrickRED::FILE_PERMISSION_OTHERS_ALL = 7
 * BrickRED::FILE_PERMISSION_OTHERS_READ = 4
 * BrickRED::FILE_PERMISSION_OTHERS_WRITE = 2
 * BrickRED::FILE_PERMISSION_OTHERS_EXECUTE = 1
 
.. php:function:: array BrickRED::getProcesses(int $session_id)

 
 The returned array has the keys ``error_code`` and ``processes_list_id``.

.. php:function:: array BrickRED::spawnProcess(int $executable_string_id, int $arguments_list_id, int $environment_list_id, int $working_directory_string_id, int $uid, int $gid, int $stdin_file_id, int $stdout_file_id, int $stderr_file_id, int $session_id)

 
 The returned array has the keys ``error_code`` and ``process_id``.

.. php:function:: int BrickRED::killProcess(int $process_id, int $signal)

 Sends a UNIX signal to a process object and returns the resulting error code.
 
 Possible UNIX signals are:
 
 * Interrupt = 2
 * Quit = 3
 * Abort = 6
 * Kill = 9
 * User1 = 10
 * User2 = 12
 * Terminate = 15
 * Continue =  18
 * Stop = 19
 
 The following constants are available for this function:
 
 * BrickRED::PROCESS_SIGNAL_INTERRUPT = 2
 * BrickRED::PROCESS_SIGNAL_QUIT = 3
 * BrickRED::PROCESS_SIGNAL_ABORT = 6
 * BrickRED::PROCESS_SIGNAL_KILL = 9
 * BrickRED::PROCESS_SIGNAL_USER1 = 10
 * BrickRED::PROCESS_SIGNAL_USER2 = 12
 * BrickRED::PROCESS_SIGNAL_TERMINATE = 15
 * BrickRED::PROCESS_SIGNAL_CONTINUE = 18
 * BrickRED::PROCESS_SIGNAL_STOP = 19
 
.. php:function:: array BrickRED::getProcessCommand(int $process_id, int $session_id)

 Returns the executable, arguments, environment and working directory used to
 spawn a process object, as passed to :php:func:`spawnProcess() <BrickRED::spawnProcess>`, and the resulting
 error code.
 
 The returned array has the keys ``error_code``, ``executable_string_id``, ``arguments_list_id``, ``environment_list_id`` and ``working_directory_string_id``.

.. php:function:: array BrickRED::getProcessIdentity(int $process_id)

 Returns the process ID and the user and group ID used to spawn a process object,
 as passed to :php:func:`spawnProcess() <BrickRED::spawnProcess>`, and the resulting error code.
 
 The process ID is only valid if the state is *Running* or *Stopped*, see
 :php:func:`getProcessState() <BrickRED::getProcessState>`.
 
 The returned array has the keys ``error_code``, ``pid``, ``uid`` and ``gid``.

.. php:function:: array BrickRED::getProcessStdio(int $process_id, int $session_id)

 Returns the stdin, stdout and stderr files used to spawn a process object, as
 passed to :php:func:`spawnProcess() <BrickRED::spawnProcess>`, and the resulting error code.
 
 The returned array has the keys ``error_code``, ``stdin_file_id``, ``stdout_file_id`` and ``stderr_file_id``.

.. php:function:: array BrickRED::getProcessState(int $process_id)

 Returns the current state, timestamp and exit code of a process object, and
 the resulting error code.
 
 Possible process states are:
 
 * Unknown = 0
 * Running = 1
 * Error = 2
 * Exited = 3
 * Killed = 4
 * Stopped = 5
 
 The timestamp represents the UNIX time since when the process is in its current
 state.
 
 The exit code is only valid if the state is *Error*, *Exited*, *Killed* or
 *Stopped* and has different meanings depending on the state:
 
 * Error: error code for error occurred while spawning the process (see below)
 * Exited: exit status of the process
 * Killed: UNIX signal number used to kill the process
 * Stopped: UNIX signal number used to stop the process
 
 Possible exit/error codes in *Error* state are:
 
 * InternalError = 125
 * CannotExecute = 126
 * DoesNotExist = 127
 
 The *CannotExecute* error can be caused by the executable being opened for
 writing.
 
 The following constants are available for this function:
 
 * BrickRED::PROCESS_STATE_UNKNOWN = 0
 * BrickRED::PROCESS_STATE_RUNNING = 1
 * BrickRED::PROCESS_STATE_ERROR = 2
 * BrickRED::PROCESS_STATE_EXITED = 3
 * BrickRED::PROCESS_STATE_KILLED = 4
 * BrickRED::PROCESS_STATE_STOPPED = 5
 
 The returned array has the keys ``error_code``, ``state``, ``timestamp`` and ``exit_code``.

.. php:function:: array BrickRED::getPrograms(int $session_id)

 
 The returned array has the keys ``error_code`` and ``programs_list_id``.

.. php:function:: array BrickRED::defineProgram(int $identifier_string_id, int $session_id)

 
 The returned array has the keys ``error_code`` and ``program_id``.

.. php:function:: int BrickRED::purgeProgram(int $program_id, int $cookie)

 
.. php:function:: array BrickRED::getProgramIdentifier(int $program_id, int $session_id)

 
 The returned array has the keys ``error_code`` and ``identifier_string_id``.

.. php:function:: array BrickRED::getProgramRootDirectory(int $program_id, int $session_id)

 FIXME: root directory is absolute: <home>/programs/<identifier>
 
 The returned array has the keys ``error_code`` and ``root_directory_string_id``.

.. php:function:: int BrickRED::setProgramCommand(int $program_id, int $executable_string_id, int $arguments_list_id, int $environment_list_id, int $working_directory_string_id)

 FIXME: working directory is relative to <home>/programs/<identifier>/bin
 
.. php:function:: array BrickRED::getProgramCommand(int $program_id, int $session_id)

 FIXME: working directory is relative to <home>/programs/<identifier>/bin
 
 The returned array has the keys ``error_code``, ``executable_string_id``, ``arguments_list_id``, ``environment_list_id`` and ``working_directory_string_id``.

.. php:function:: int BrickRED::setProgramStdioRedirection(int $program_id, int $stdin_redirection, int $stdin_file_name_string_id, int $stdout_redirection, int $stdout_file_name_string_id, int $stderr_redirection, int $stderr_file_name_string_id)

 FIXME: stdio file names are relative to <home>/programs/<identifier>/bin
 
 The following constants are available for this function:
 
 * BrickRED::PROGRAM_STDIO_REDIRECTION_DEV_NULL = 0
 * BrickRED::PROGRAM_STDIO_REDIRECTION_PIPE = 1
 * BrickRED::PROGRAM_STDIO_REDIRECTION_FILE = 2
 * BrickRED::PROGRAM_STDIO_REDIRECTION_INDIVIDUAL_LOG = 3
 * BrickRED::PROGRAM_STDIO_REDIRECTION_CONTINUOUS_LOG = 4
 * BrickRED::PROGRAM_STDIO_REDIRECTION_STDOUT = 5
 
.. php:function:: array BrickRED::getProgramStdioRedirection(int $program_id, int $session_id)

 FIXME: stdio file names are relative to <home>/programs/<identifier>/bin
 
 The following constants are available for this function:
 
 * BrickRED::PROGRAM_STDIO_REDIRECTION_DEV_NULL = 0
 * BrickRED::PROGRAM_STDIO_REDIRECTION_PIPE = 1
 * BrickRED::PROGRAM_STDIO_REDIRECTION_FILE = 2
 * BrickRED::PROGRAM_STDIO_REDIRECTION_INDIVIDUAL_LOG = 3
 * BrickRED::PROGRAM_STDIO_REDIRECTION_CONTINUOUS_LOG = 4
 * BrickRED::PROGRAM_STDIO_REDIRECTION_STDOUT = 5
 
 The returned array has the keys ``error_code``, ``stdin_redirection``, ``stdin_file_name_string_id``, ``stdout_redirection``, ``stdout_file_name_string_id``, ``stderr_redirection`` and ``stderr_file_name_string_id``.

.. php:function:: int BrickRED::setProgramSchedule(int $program_id, int $start_mode, bool $continue_after_error, int $start_interval, int $start_fields_string_id)

 
 The following constants are available for this function:
 
 * BrickRED::PROGRAM_START_MODE_NEVER = 0
 * BrickRED::PROGRAM_START_MODE_ALWAYS = 1
 * BrickRED::PROGRAM_START_MODE_INTERVAL = 2
 * BrickRED::PROGRAM_START_MODE_CRON = 3
 
.. php:function:: array BrickRED::getProgramSchedule(int $program_id, int $session_id)

 
 The following constants are available for this function:
 
 * BrickRED::PROGRAM_START_MODE_NEVER = 0
 * BrickRED::PROGRAM_START_MODE_ALWAYS = 1
 * BrickRED::PROGRAM_START_MODE_INTERVAL = 2
 * BrickRED::PROGRAM_START_MODE_CRON = 3
 
 The returned array has the keys ``error_code``, ``start_mode``, ``continue_after_error``, ``start_interval`` and ``start_fields_string_id``.

.. php:function:: array BrickRED::getProgramSchedulerState(int $program_id, int $session_id)

 FIXME: message is currently valid in error-occurred state only
 
 The following constants are available for this function:
 
 * BrickRED::PROGRAM_SCHEDULER_STATE_STOPPED = 0
 * BrickRED::PROGRAM_SCHEDULER_STATE_RUNNING = 1
 
 The returned array has the keys ``error_code``, ``state``, ``timestamp`` and ``message_string_id``.

.. php:function:: int BrickRED::continueProgramSchedule(int $program_id)

 
.. php:function:: int BrickRED::startProgram(int $program_id)

 
.. php:function:: array BrickRED::getLastSpawnedProgramProcess(int $program_id, int $session_id)

 
 The returned array has the keys ``error_code``, ``process_id`` and ``timestamp``.

.. php:function:: array BrickRED::getCustomProgramOptionNames(int $program_id, int $session_id)

 
 The returned array has the keys ``error_code`` and ``names_list_id``.

.. php:function:: int BrickRED::setCustomProgramOptionValue(int $program_id, int $name_string_id, int $value_string_id)

 
.. php:function:: array BrickRED::getCustomProgramOptionValue(int $program_id, int $name_string_id, int $session_id)

 
 The returned array has the keys ``error_code`` and ``value_string_id``.

.. php:function:: int BrickRED::removeCustomProgramOption(int $program_id, int $name_string_id)

 
.. php:function:: array BrickRED::getAPIVersion()

 Returns the version of the API definition (major, minor, revision) implemented
 by this API bindings. This is neither the release version of this API bindings
 nor does it tell you anything about the represented Brick or Bricklet.
 
.. php:function:: bool BrickRED::getResponseExpected(int $function_id)

 Returns the response expected flag for the function specified by the function
 ID parameter. It is *true* if the function is expected to send a response,
 *false* otherwise.
 
 For getter functions this is enabled by default and cannot be disabled,
 because those functions will always send a response. For callback configuration
 functions it is enabled by default too, but can be disabled by
 :php:func:`setResponseExpected() <BrickRED::setResponseExpected>`. For setter functions it is disabled by default
 and can be enabled.
 
 Enabling the response expected flag for a setter function allows to detect
 timeouts and other error conditions calls of this setter as well. The
 device will then send a response for this purpose. If this flag is disabled for
 a setter function then no response is send and errors are silently ignored,
 because they cannot be detected.
 
 See :php:func:`setResponseExpected() <BrickRED::setResponseExpected>`
 for the list of function ID constants available for this function.
 
.. php:function:: void BrickRED::setResponseExpected(int $function_id, bool $response_expected)

 Changes the response expected flag of the function specified by the
 function ID parameter. This flag can only be changed for setter (default value:
 *false*) and callback configuration functions (default value: *true*). For
 getter functions it is always enabled and callbacks it is always disabled.
 
 Enabling the response expected flag for a setter function allows to detect
 timeouts and other error conditions calls of this setter as well. The
 device will then send a response for this purpose. If this flag is disabled for
 a setter function then no response is send and errors are silently ignored,
 because they cannot be detected.
 
 The following function ID constants are available for this function:
 
 * BrickRED::FUNCTION_EXPIRE_SESSION_UNCHECKED = 3
 * BrickRED::FUNCTION_RELEASE_OBJECT_UNCHECKED = 6
 * BrickRED::FUNCTION_READ_FILE_ASYNC = 21
 * BrickRED::FUNCTION_WRITE_FILE_UNCHECKED = 24
 * BrickRED::FUNCTION_WRITE_FILE_ASYNC = 25
 
.. php:function:: void BrickRED::setResponseExpectedAll(bool $response_expected)

 Changes the response expected flag for all setter and callback configuration
 functions of this device at once.
 
.. php:function:: array BrickRED::getIdentity()

 Returns the UID, the UID where the Brick is connected to, 
 the position, the hardware and firmware version as well as the
 device identifier.
 
 The position can be '0'-'8' (stack position).
 
 The device identifier numbers can be found :ref:`here <device_identifier>`.
 |device_identifier_constant|
 
 The returned array has the keys ``uid``, ``connected_uid``, ``position``, ``hardware_version``, ``firmware_version`` and ``device_identifier``.



Callback Configuration Functions
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^


.. php:function:: void BrickRED::registerCallback(int $id, callable $callback, mixed $userData = NULL)

 Registers a callback with ID *$id* to the callable *$callback*.
 The *$userData*  will be given as a parameter of the callback.

 The available  IDs with corresponding function signatures are listed
 :ref:`below <red_brick_php_callbacks>`.




.. _red_brick_php_callbacks:

Callbacks
^^^^^^^^^

Callbacks can be registered to receive
time critical or recurring data from the device. The registration is done
with the :php:func:`registerCallback() <BrickRED::registerCallback>` function of
the device object. The first parameter is the callback ID and the second
parameter the callback function:

.. code-block:: php

    <?php

    function myCallback($param)
    {
        echo $param . "\n";
    }

    $red->registerCallback(BrickRED::CALLBACK_EXAMPLE, 'myCallback');

    ?>

The available constants with corresponding function signatures are
described below.

.. note::
 Using callbacks for recurring events is *always* preferred
 compared to using getters. It will use less USB bandwidth and the latency
 will be a lot better, since there is no round trip time.

.. php:member:: int BrickRED::CALLBACK_ASYNC_FILE_READ

 .. code-block:: php

  <?php   void callback(int $file_id, int $error_code, array $buffer, int $length_read [, mixed $userData])   ?>

 This callback reports the result of a call to the :php:func:`readFileAsync() <BrickRED::readFileAsync>`
 function.
 
.. php:member:: int BrickRED::CALLBACK_ASYNC_FILE_WRITE

 .. code-block:: php

  <?php   void callback(int $file_id, int $error_code, int $length_written [, mixed $userData])   ?>

 This callback reports the result of a call to the :php:func:`writeFileAsync() <BrickRED::writeFileAsync>`
 function.
 
.. php:member:: int BrickRED::CALLBACK_FILE_EVENTS_OCCURRED

 .. code-block:: php

  <?php   void callback(int $file_id, int $events [, mixed $userData])   ?>

 
 The following constants are available for this function:
 
 * BrickRED::FILE_EVENT_READABLE = 1
 * BrickRED::FILE_EVENT_WRITABLE = 2
 
.. php:member:: int BrickRED::CALLBACK_PROCESS_STATE_CHANGED

 .. code-block:: php

  <?php   void callback(int $process_id, int $state, int $timestamp, int $exit_code [, mixed $userData])   ?>

 
 The following constants are available for this function:
 
 * BrickRED::PROCESS_STATE_UNKNOWN = 0
 * BrickRED::PROCESS_STATE_RUNNING = 1
 * BrickRED::PROCESS_STATE_ERROR = 2
 * BrickRED::PROCESS_STATE_EXITED = 3
 * BrickRED::PROCESS_STATE_KILLED = 4
 * BrickRED::PROCESS_STATE_STOPPED = 5
 
.. php:member:: int BrickRED::CALLBACK_PROGRAM_SCHEDULER_STATE_CHANGED

 .. code-block:: php

  <?php   void callback(int $program_id [, mixed $userData])   ?>

 
.. php:member:: int BrickRED::CALLBACK_PROGRAM_PROCESS_SPAWNED

 .. code-block:: php

  <?php   void callback(int $program_id [, mixed $userData])   ?>

 


.. _red_brick_php_constants:

Constants
^^^^^^^^^

.. php:member:: int BrickRED::DEVICE_IDENTIFIER

 This constant is used to identify a RED Brick.

 The :php:func:`getIdentity() <BrickRED::getIdentity>` function and the
 :php:member:`CALLBACK_ENUMERATE <IPConnection::CALLBACK_ENUMERATE>`
 callback of the IP Connection have a ``deviceIdentifier`` parameter to specify
 the Brick's or Bricklet's type.

