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# Delphi/Lazarus - RED Brick

This is the description of the Delphi/Lazarus API bindings for the RED Brick. General information and technical specifications for the RED Brick are summarized in its hardware description.

An installation guide for the Delphi/Lazarus API bindings is part of their general description.

## Examples

The example code below is Public Domain (CC0 1.0).

## API

Since Delphi does not support multiple return values directly, we use the `out` keyword to return multiple values from a function.

All functions and procedures listed below are thread-safe.

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. `AllocateString` and `GetNextDirectoryEntry`) increase the reference count of the returned object. If the object is no longer needed then `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 `ReleaseObject` must not be called for such an object in response to a callback.

There are functions (e.g. `GetFileInfo`) that only return valid objects under certain conditions. This conditions are documented for the specific functions. For invalid objects `ReleaseObject` must not be called.

There are also function (e.g. `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 TCP/IP protocol 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

procedure `TBrickRED.``CreateSession`(const lifetime: longword; out errorCode: byte; out sessionId: word)

function `TBrickRED.``ExpireSession`(const sessionId: word): byte

procedure `TBrickRED.``ExpireSessionUnchecked`(const sessionId: word)

function `TBrickRED.``KeepSessionAlive`(const sessionId: word; const lifetime: longword): byte

function `TBrickRED.``ReleaseObject`(const objectId: word; const sessionId: word): byte

  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.

procedure `TBrickRED.``ReleaseObjectUnchecked`(const objectId: word; const sessionId: word)

procedure `TBrickRED.``AllocateString`(const lengthToReserve: longword; const buffer: string; const sessionId: word; out errorCode: byte; out stringId: word)

  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.

function `TBrickRED.``TruncateString`(const stringId: word; const length: longword): byte

  Truncates a string object to `length` bytes and returns the resulting error code.

procedure `TBrickRED.``GetStringLength`(const stringId: word; out errorCode: byte; out length: longword)

  Returns the length of a string object in bytes and the resulting error code.

function `TBrickRED.``SetStringChunk`(const stringId: word; const offset: longword; const buffer: string): byte

  Sets a chunk of up to 58 bytes in a string object beginning at `offset`.

  Returns the resulting error code.

procedure `TBrickRED.``GetStringChunk`(const stringId: word; const offset: longword; out errorCode: byte; out buffer: string)

  Returns a chunk up to 63 bytes from a string object beginning at `offset` and returns the resulting error code.

procedure `TBrickRED.``AllocateList`(const lengthToReserve: word; const sessionId: word; out errorCode: byte; out listId: word)

  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.

procedure `TBrickRED.``GetListLength`(const listId: word; out errorCode: byte; out length: word)

  Returns the length of a list object in items and the resulting error code.

procedure `TBrickRED.``GetListItem`(const listId: word; const index: word; const sessionId: word; out errorCode: byte; out itemObjectId: word; out type: byte)

  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:

  - BRICK_RED_OBJECT_TYPE_STRING = 0
  - BRICK_RED_OBJECT_TYPE_LIST = 1
  - BRICK_RED_OBJECT_TYPE_FILE = 2
  - BRICK_RED_OBJECT_TYPE_DIRECTORY = 3
  - BRICK_RED_OBJECT_TYPE_PROCESS = 4
  - BRICK_RED_OBJECT_TYPE_PROGRAM = 5

function `TBrickRED.``AppendToList`(const listId: word; const itemObjectId: word): byte

  Appends an object to a list object and increases the reference count of the appended object by one.

  Returns the resulting error code.

function `TBrickRED.``RemoveFromList`(const listId: word; const index: word): byte

  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.

procedure `TBrickRED.``OpenFile`(const nameStringId: word; const flags: longword; const permissions: word; const uid: longword; const gid: longword; const sessionId: word; out errorCode: byte; out fileId: word)

  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:

  - BRICK_RED_FILE_FLAG_READ_ONLY = 1
  - BRICK_RED_FILE_FLAG_WRITE_ONLY = 2
  - BRICK_RED_FILE_FLAG_READ_WRITE = 4
  - BRICK_RED_FILE_FLAG_APPEND = 8
  - BRICK_RED_FILE_FLAG_CREATE = 16
  - BRICK_RED_FILE_FLAG_EXCLUSIVE = 32
  - BRICK_RED_FILE_FLAG_NON_BLOCKING = 64
  - BRICK_RED_FILE_FLAG_TRUNCATE = 128
  - BRICK_RED_FILE_FLAG_TEMPORARY = 256
  - BRICK_RED_FILE_FLAG_REPLACE = 512
  - BRICK_RED_FILE_PERMISSION_USER_ALL = 448
  - BRICK_RED_FILE_PERMISSION_USER_READ = 256
  - BRICK_RED_FILE_PERMISSION_USER_WRITE = 128
  - BRICK_RED_FILE_PERMISSION_USER_EXECUTE = 64
  - BRICK_RED_FILE_PERMISSION_GROUP_ALL = 56
  - BRICK_RED_FILE_PERMISSION_GROUP_READ = 32
  - BRICK_RED_FILE_PERMISSION_GROUP_WRITE = 16
  - BRICK_RED_FILE_PERMISSION_GROUP_EXECUTE = 8
  - BRICK_RED_FILE_PERMISSION_OTHERS_ALL = 7
  - BRICK_RED_FILE_PERMISSION_OTHERS_READ = 4
  - BRICK_RED_FILE_PERMISSION_OTHERS_WRITE = 2
  - BRICK_RED_FILE_PERMISSION_OTHERS_EXECUTE = 1

procedure `TBrickRED.``CreatePipe`(const flags: longword; const length: uint64; const sessionId: word; out errorCode: byte; out fileId: word)

  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:

  - BRICK_RED_PIPE_FLAG_NON_BLOCKING_READ = 1
  - BRICK_RED_PIPE_FLAG_NON_BLOCKING_WRITE = 2

procedure `TBrickRED.``GetFileInfo`(const fileId: word; const sessionId: word; out errorCode: byte; out type: byte; out nameStringId: word; out flags: longword; out permissions: word; out uid: longword; out gid: longword; out length: uint64; out accessTimestamp: uint64; out modificationTimestamp: uint64; out statusChangeTimestamp: uint64)

  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 `OpenFile`.

  The returned flags were used to open or create the file object, as passed to `OpenFile` or `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:

  - BRICK_RED_FILE_TYPE_UNKNOWN = 0
  - BRICK_RED_FILE_TYPE_REGULAR = 1
  - BRICK_RED_FILE_TYPE_DIRECTORY = 2
  - BRICK_RED_FILE_TYPE_CHARACTER = 3
  - BRICK_RED_FILE_TYPE_BLOCK = 4
  - BRICK_RED_FILE_TYPE_FIFO = 5
  - BRICK_RED_FILE_TYPE_SYMLINK = 6
  - BRICK_RED_FILE_TYPE_SOCKET = 7
  - BRICK_RED_FILE_TYPE_PIPE = 8
  - BRICK_RED_FILE_PERMISSION_USER_ALL = 448
  - BRICK_RED_FILE_PERMISSION_USER_READ = 256
  - BRICK_RED_FILE_PERMISSION_USER_WRITE = 128
  - BRICK_RED_FILE_PERMISSION_USER_EXECUTE = 64
  - BRICK_RED_FILE_PERMISSION_GROUP_ALL = 56
  - BRICK_RED_FILE_PERMISSION_GROUP_READ = 32
  - BRICK_RED_FILE_PERMISSION_GROUP_WRITE = 16
  - BRICK_RED_FILE_PERMISSION_GROUP_EXECUTE = 8
  - BRICK_RED_FILE_PERMISSION_OTHERS_ALL = 7
  - BRICK_RED_FILE_PERMISSION_OTHERS_READ = 4
  - BRICK_RED_FILE_PERMISSION_OTHERS_WRITE = 2
  - BRICK_RED_FILE_PERMISSION_OTHERS_EXECUTE = 1

procedure `TBrickRED.``ReadFile`(const fileId: word; const lengthToRead: byte; out errorCode: byte; out buffer: array [0..61] of byte; out lengthRead: byte)

  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 `OpenFile` without the NonBlocking flag or by `CreatePipe` without the NonBlockingRead flag then the error code NotSupported is returned.

procedure `TBrickRED.``ReadFileAsync`(const fileId: word; const lengthToRead: uint64)

  Reads up to 263 - 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 `OnAsyncFileRead` 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 `OpenFile` without the NonBlocking flag or by `CreatePipe` without the NonBlockingRead flag then the error code NotSupported is reported via the `OnAsyncFileRead` callback.

function `TBrickRED.``AbortAsyncFileRead`(const fileId: word): byte

  Aborts a `ReadFileAsync` operation in progress.

  Returns the resulting error code.

  On success the `OnAsyncFileRead` callback will report OperationAborted.

procedure `TBrickRED.``WriteFile`(const fileId: word; const buffer: array [0..60] of byte; const lengthToWrite: byte; out errorCode: byte; out lengthWritten: byte)

  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 `OpenFile` without the NonBlocking flag or by `CreatePipe` without the NonBlockingWrite flag then the error code NotSupported is returned.

procedure `TBrickRED.``WriteFileUnchecked`(const fileId: word; const buffer: array [0..60] of byte; const lengthToWrite: byte)

  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 `OpenFile` without the NonBlocking flag or by `CreatePipe` without the NonBlockingWrite flag then the write operation will fail silently.

procedure `TBrickRED.``WriteFileAsync`(const fileId: word; const buffer: array [0..60] of byte; const lengthToWrite: byte)

  Writes up to 61 bytes to a file object.

  Reports the actual number of bytes written and the resulting error code via the `OnAsyncFileWrite` callback.

  If the file object was created by `OpenFile` without the NonBlocking flag or by `CreatePipe` without the NonBlockingWrite flag then the error code NotSupported is reported via the `OnAsyncFileWrite` callback.

procedure `TBrickRED.``SetFilePosition`(const fileId: word; const offset: int64; const origin: byte; out errorCode: byte; out position: uint64)

  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 `CreatePipe` then it has no seek position and the error code InvalidSeek is returned.

  The following constants are available for this function:

  - BRICK_RED_FILE_ORIGIN_BEGINNING = 0
  - BRICK_RED_FILE_ORIGIN_CURRENT = 1
  - BRICK_RED_FILE_ORIGIN_END = 2

procedure `TBrickRED.``GetFilePosition`(const fileId: word; out errorCode: byte; out position: uint64)

  Returns the current seek position of a file object in bytes and returns the resulting error code.

  If the file object was created by `CreatePipe` then it has no seek position and the error code InvalidSeek is returned.

function `TBrickRED.``SetFileEvents`(const fileId: word; const events: word): byte

  The following constants are available for this function:

  - BRICK_RED_FILE_EVENT_READABLE = 1
  - BRICK_RED_FILE_EVENT_WRITABLE = 2

procedure `TBrickRED.``GetFileEvents`(const fileId: word; out errorCode: byte; out events: word)

  The following constants are available for this function:

  - BRICK_RED_FILE_EVENT_READABLE = 1
  - BRICK_RED_FILE_EVENT_WRITABLE = 2

procedure `TBrickRED.``OpenDirectory`(const nameStringId: word; const sessionId: word; out errorCode: byte; out directoryId: word)

  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.

procedure `TBrickRED.``GetDirectoryName`(const directoryId: word; const sessionId: word; out errorCode: byte; out nameStringId: word)

  Returns the name of a directory object, as passed to `OpenDirectory`, and the resulting error code.

procedure `TBrickRED.``GetNextDirectoryEntry`(const directoryId: word; const sessionId: word; out errorCode: byte; out nameStringId: word; out type: byte)

  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 `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:

  - BRICK_RED_DIRECTORY_ENTRY_TYPE_UNKNOWN = 0
  - BRICK_RED_DIRECTORY_ENTRY_TYPE_REGULAR = 1
  - BRICK_RED_DIRECTORY_ENTRY_TYPE_DIRECTORY = 2
  - BRICK_RED_DIRECTORY_ENTRY_TYPE_CHARACTER = 3
  - BRICK_RED_DIRECTORY_ENTRY_TYPE_BLOCK = 4
  - BRICK_RED_DIRECTORY_ENTRY_TYPE_FIFO = 5
  - BRICK_RED_DIRECTORY_ENTRY_TYPE_SYMLINK = 6
  - BRICK_RED_DIRECTORY_ENTRY_TYPE_SOCKET = 7

function `TBrickRED.``RewindDirectory`(const directoryId: word): byte

  Rewinds a directory object and returns the resulting error code.

function `TBrickRED.``CreateDirectory`(const nameStringId: word; const flags: longword; const permissions: word; const uid: longword; const gid: longword): byte

  FIXME: name has to be absolute

  The following constants are available for this function:

  - BRICK_RED_DIRECTORY_FLAG_RECURSIVE = 1
  - BRICK_RED_DIRECTORY_FLAG_EXCLUSIVE = 2
  - BRICK_RED_FILE_PERMISSION_USER_ALL = 448
  - BRICK_RED_FILE_PERMISSION_USER_READ = 256
  - BRICK_RED_FILE_PERMISSION_USER_WRITE = 128
  - BRICK_RED_FILE_PERMISSION_USER_EXECUTE = 64
  - BRICK_RED_FILE_PERMISSION_GROUP_ALL = 56
  - BRICK_RED_FILE_PERMISSION_GROUP_READ = 32
  - BRICK_RED_FILE_PERMISSION_GROUP_WRITE = 16
  - BRICK_RED_FILE_PERMISSION_GROUP_EXECUTE = 8
  - BRICK_RED_FILE_PERMISSION_OTHERS_ALL = 7
  - BRICK_RED_FILE_PERMISSION_OTHERS_READ = 4
  - BRICK_RED_FILE_PERMISSION_OTHERS_WRITE = 2
  - BRICK_RED_FILE_PERMISSION_OTHERS_EXECUTE = 1

procedure `TBrickRED.``GetProcesses`(const sessionId: word; out errorCode: byte; out processesListId: word)

procedure `TBrickRED.``SpawnProcess`(const executableStringId: word; const argumentsListId: word; const environmentListId: word; const workingDirectoryStringId: word; const uid: longword; const gid: longword; const stdinFileId: word; const stdoutFileId: word; const stderrFileId: word; const sessionId: word; out errorCode: byte; out processId: word)

function `TBrickRED.``KillProcess`(const processId: word; const signal: byte): byte

  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:

  - BRICK_RED_PROCESS_SIGNAL_INTERRUPT = 2
  - BRICK_RED_PROCESS_SIGNAL_QUIT = 3
  - BRICK_RED_PROCESS_SIGNAL_ABORT = 6
  - BRICK_RED_PROCESS_SIGNAL_KILL = 9
  - BRICK_RED_PROCESS_SIGNAL_USER1 = 10
  - BRICK_RED_PROCESS_SIGNAL_USER2 = 12
  - BRICK_RED_PROCESS_SIGNAL_TERMINATE = 15
  - BRICK_RED_PROCESS_SIGNAL_CONTINUE = 18
  - BRICK_RED_PROCESS_SIGNAL_STOP = 19

procedure `TBrickRED.``GetProcessCommand`(const processId: word; const sessionId: word; out errorCode: byte; out executableStringId: word; out argumentsListId: word; out environmentListId: word; out workingDirectoryStringId: word)

  Returns the executable, arguments, environment and working directory used to spawn a process object, as passed to `SpawnProcess`, and the resulting error code.

procedure `TBrickRED.``GetProcessIdentity`(const processId: word; out errorCode: byte; out pid: longword; out uid: longword; out gid: longword)

  Returns the process ID and the user and group ID used to spawn a process object, as passed to `SpawnProcess`, and the resulting error code.

  The process ID is only valid if the state is Running or Stopped, see `GetProcessState`.

procedure `TBrickRED.``GetProcessStdio`(const processId: word; const sessionId: word; out errorCode: byte; out stdinFileId: word; out stdoutFileId: word; out stderrFileId: word)

  Returns the stdin, stdout and stderr files used to spawn a process object, as passed to `SpawnProcess`, and the resulting error code.

procedure `TBrickRED.``GetProcessState`(const processId: word; out errorCode: byte; out state: byte; out timestamp: uint64; out exitCode: byte)

  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:

  - BRICK_RED_PROCESS_STATE_UNKNOWN = 0
  - BRICK_RED_PROCESS_STATE_RUNNING = 1
  - BRICK_RED_PROCESS_STATE_ERROR = 2
  - BRICK_RED_PROCESS_STATE_EXITED = 3
  - BRICK_RED_PROCESS_STATE_KILLED = 4
  - BRICK_RED_PROCESS_STATE_STOPPED = 5

procedure `TBrickRED.``GetPrograms`(const sessionId: word; out errorCode: byte; out programsListId: word)

procedure `TBrickRED.``DefineProgram`(const identifierStringId: word; const sessionId: word; out errorCode: byte; out programId: word)

function `TBrickRED.``PurgeProgram`(const programId: word; const cookie: longword): byte

procedure `TBrickRED.``GetProgramIdentifier`(const programId: word; const sessionId: word; out errorCode: byte; out identifierStringId: word)

procedure `TBrickRED.``GetProgramRootDirectory`(const programId: word; const sessionId: word; out errorCode: byte; out rootDirectoryStringId: word)

  FIXME: root directory is absolute: <home>/programs/<identifier>

function `TBrickRED.``SetProgramCommand`(const programId: word; const executableStringId: word; const argumentsListId: word; const environmentListId: word; const workingDirectoryStringId: word): byte

  FIXME: working directory is relative to <home>/programs/<identifier>/bin

procedure `TBrickRED.``GetProgramCommand`(const programId: word; const sessionId: word; out errorCode: byte; out executableStringId: word; out argumentsListId: word; out environmentListId: word; out workingDirectoryStringId: word)

  FIXME: working directory is relative to <home>/programs/<identifier>/bin

function `TBrickRED.``SetProgramStdioRedirection`(const programId: word; const stdinRedirection: byte; const stdinFileNameStringId: word; const stdoutRedirection: byte; const stdoutFileNameStringId: word; const stderrRedirection: byte; const stderrFileNameStringId: word): byte

  FIXME: stdio file names are relative to <home>/programs/<identifier>/bin

  The following constants are available for this function:

  - BRICK_RED_PROGRAM_STDIO_REDIRECTION_DEV_NULL = 0
  - BRICK_RED_PROGRAM_STDIO_REDIRECTION_PIPE = 1
  - BRICK_RED_PROGRAM_STDIO_REDIRECTION_FILE = 2
  - BRICK_RED_PROGRAM_STDIO_REDIRECTION_INDIVIDUAL_LOG = 3
  - BRICK_RED_PROGRAM_STDIO_REDIRECTION_CONTINUOUS_LOG = 4
  - BRICK_RED_PROGRAM_STDIO_REDIRECTION_STDOUT = 5

procedure `TBrickRED.``GetProgramStdioRedirection`(const programId: word; const sessionId: word; out errorCode: byte; out stdinRedirection: byte; out stdinFileNameStringId: word; out stdoutRedirection: byte; out stdoutFileNameStringId: word; out stderrRedirection: byte; out stderrFileNameStringId: word)

  FIXME: stdio file names are relative to <home>/programs/<identifier>/bin

  The following constants are available for this function:

  - BRICK_RED_PROGRAM_STDIO_REDIRECTION_DEV_NULL = 0
  - BRICK_RED_PROGRAM_STDIO_REDIRECTION_PIPE = 1
  - BRICK_RED_PROGRAM_STDIO_REDIRECTION_FILE = 2
  - BRICK_RED_PROGRAM_STDIO_REDIRECTION_INDIVIDUAL_LOG = 3
  - BRICK_RED_PROGRAM_STDIO_REDIRECTION_CONTINUOUS_LOG = 4
  - BRICK_RED_PROGRAM_STDIO_REDIRECTION_STDOUT = 5

function `TBrickRED.``SetProgramSchedule`(const programId: word; const startMode: byte; const continueAfterError: boolean; const startInterval: longword; const startFieldsStringId: word): byte

  The following constants are available for this function:

  - BRICK_RED_PROGRAM_START_MODE_NEVER = 0
  - BRICK_RED_PROGRAM_START_MODE_ALWAYS = 1
  - BRICK_RED_PROGRAM_START_MODE_INTERVAL = 2
  - BRICK_RED_PROGRAM_START_MODE_CRON = 3

procedure `TBrickRED.``GetProgramSchedule`(const programId: word; const sessionId: word; out errorCode: byte; out startMode: byte; out continueAfterError: boolean; out startInterval: longword; out startFieldsStringId: word)

  The following constants are available for this function:

  - BRICK_RED_PROGRAM_START_MODE_NEVER = 0
  - BRICK_RED_PROGRAM_START_MODE_ALWAYS = 1
  - BRICK_RED_PROGRAM_START_MODE_INTERVAL = 2
  - BRICK_RED_PROGRAM_START_MODE_CRON = 3

procedure `TBrickRED.``GetProgramSchedulerState`(const programId: word; const sessionId: word; out errorCode: byte; out state: byte; out timestamp: uint64; out messageStringId: word)

  FIXME: message is currently valid in error-occurred state only

  The following constants are available for this function:

  - BRICK_RED_PROGRAM_SCHEDULER_STATE_STOPPED = 0
  - BRICK_RED_PROGRAM_SCHEDULER_STATE_RUNNING = 1

function `TBrickRED.``ContinueProgramSchedule`(const programId: word): byte

function `TBrickRED.``StartProgram`(const programId: word): byte

procedure `TBrickRED.``GetLastSpawnedProgramProcess`(const programId: word; const sessionId: word; out errorCode: byte; out processId: word; out timestamp: uint64)

procedure `TBrickRED.``GetCustomProgramOptionNames`(const programId: word; const sessionId: word; out errorCode: byte; out namesListId: word)

function `TBrickRED.``SetCustomProgramOptionValue`(const programId: word; const nameStringId: word; const valueStringId: word): byte

procedure `TBrickRED.``GetCustomProgramOptionValue`(const programId: word; const nameStringId: word; const sessionId: word; out errorCode: byte; out valueStringId: word)

function `TBrickRED.``RemoveCustomProgramOption`(const programId: word; const nameStringId: word): byte

function `TBrickRED.``GetAPIVersion`: array [0..2] of byte

  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.

function `TBrickRED.``GetResponseExpected`(const functionId: byte): boolean

  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 `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 `SetResponseExpected` for the list of function ID constants available for this function.

procedure `TBrickRED.``SetResponseExpected`(const functionId: byte; const responseExpected: boolean)

  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:

  - BRICK_RED_FUNCTION_EXPIRE_SESSION_UNCHECKED = 3
  - BRICK_RED_FUNCTION_RELEASE_OBJECT_UNCHECKED = 6
  - BRICK_RED_FUNCTION_READ_FILE_ASYNC = 21
  - BRICK_RED_FUNCTION_WRITE_FILE_UNCHECKED = 24
  - BRICK_RED_FUNCTION_WRITE_FILE_ASYNC = 25

procedure `TBrickRED.``SetResponseExpectedAll`(const responseExpected: boolean)

  Changes the response expected flag for all setter and callback configuration functions of this device at once.

procedure `TBrickRED.``GetIdentity`(out uid: string; out connectedUid: string; out position: char; out hardwareVersion: array [0..2] of byte; out firmwareVersion: array [0..2] of byte; out deviceIdentifier: word)

  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 here. There is also a constant for the device identifier of this Brick.

### Callback Configuration Functions

### Callbacks

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done by assigning a procedure to an callback property of the device object:

>     procedure TExample.MyCallback(sender: TBrickRED; const param: word);
>     begin
>       WriteLn(param);
>     end;

>     red.OnExample := {$ifdef FPC}@{$endif}example.MyCallback;

The available callback property and their type of parameters 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.

property `TBrickRED.``OnAsyncFileRead`

      procedure(sender: TBrickRED; const fileId: word; const errorCode: byte; const buffer: array [0..59] of byte; const lengthRead: byte) of object;

  This callback reports the result of a call to the `ReadFileAsync` function.

property `TBrickRED.``OnAsyncFileWrite`

      procedure(sender: TBrickRED; const fileId: word; const errorCode: byte; const lengthWritten: byte) of object;

  This callback reports the result of a call to the `WriteFileAsync` function.

property `TBrickRED.``OnFileEventsOccurred`

      procedure(sender: TBrickRED; const fileId: word; const events: word) of object;

  The following constants are available for this function:

  - BRICK_RED_FILE_EVENT_READABLE = 1
  - BRICK_RED_FILE_EVENT_WRITABLE = 2

property `TBrickRED.``OnProcessStateChanged`

      procedure(sender: TBrickRED; const processId: word; const state: byte; const timestamp: uint64; const exitCode: byte) of object;

  The following constants are available for this function:

  - BRICK_RED_PROCESS_STATE_UNKNOWN = 0
  - BRICK_RED_PROCESS_STATE_RUNNING = 1
  - BRICK_RED_PROCESS_STATE_ERROR = 2
  - BRICK_RED_PROCESS_STATE_EXITED = 3
  - BRICK_RED_PROCESS_STATE_KILLED = 4
  - BRICK_RED_PROCESS_STATE_STOPPED = 5

property `TBrickRED.``OnProgramSchedulerStateChanged`

      procedure(sender: TBrickRED; const programId: word) of object;

property `TBrickRED.``OnProgramProcessSpawned`

      procedure(sender: TBrickRED; const programId: word) of object;

### Constants

const `BRICK_RED_DEVICE_IDENTIFIER`

  This constant is used to identify a RED Brick.

  The `GetIdentity` function and the `OnEnumerate` callback of the IP Connection have a `deviceIdentifier` parameter to specify the Brick's or Bricklet's type.

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