A PTY (pseudoterminal) emulates terminal devices, with a "server" side (which represents the keyboard+monitor side of the terminal and is obtained by opening /dev/misc/ptmx) and a number of "client" sides which are obtained by calling OpenClient.

Client PTYs are identified by the id used in the OpenClient call. The first Client PTY must be 0, and it is the only Client PTY that is allowed to create additional Client PTYs, receive Events, etc. It is the Controlling PTY.

PROTOCOLS

Device

Defined in fuchsia.hardware.pty/pty.fidl

AdvisoryLock

Acquires an advisory lock on the underlying file.

The lock lasts until either this connection is closed or this method is called with |AdvisoryLockType.UNLOCK| to release the lock explicitly.

Advisory locks are purely advisory. They do not prevent actual read or write operations from occurring on the file, either through this connection or through other connections.

This method requires the following rights:

• Rights.READ_BYTES if request.type is AdvisoryLockType.READ.
• Rights.WRITE_BYTES if request.type is AdvisoryLockType.WRITE.

Errors

• ZX_ERR_BAD_STATE The specified type of lock cannot be acquired. For example, another connection might hold a conflicting lock type.
• ZX_ERR_NOT_SUPPORTED This file does not support advisory locking.
• ZX_ERR_ACCESS_DENIED This connection does not have sufficient rights to acquire the given type of lock.

Request

Name	Type
request	fuchsia.io2/AdvisoryLockRequest

Response

Name	Type
result	fuchsia.io2/AdvisoryLocking_AdvisoryLock_Result

Clone

Create another connection to the same remote object.

flags may be any of:

• OPEN_RIGHT_*
• OPEN_FLAG_APPEND
• OPEN_FLAG_NO_REMOTE
• OPEN_FLAG_DESCRIBE
• CLONE_FLAG_SAME_RIGHTS

All other flags are ignored.

The OPEN_RIGHT_* bits in flags request corresponding rights over the resulting cloned object. The cloned object must have rights less than or equal to the original object, otherwise returns ZX_ERR_ACCESS_DENIED. Alternatively, pass CLONE_FLAG_SAME_RIGHTS to inherit the rights on the source connection. It is invalid to pass any of the OPEN_RIGHT_* flags together with CLONE_FLAG_SAME_RIGHTS.

Request

Name	Type
flags	uint32
object	request<fuchsia.io/Node>

Close

Terminates connection with object.

This method does not require any rights.

Request

<EMPTY>

Response

Name	Type
s	zx/status

Close2

Terminates connection with object.

This method does not require any rights.

Request

<EMPTY>

Response

Name	Type
result	fuchsia.io/Node_Close2_Result

ClrSetFeature

allowed on Client PTYs

Clear and/or Set PTY Features

Request

Name	Type
clr	uint32
set	uint32

Response

Name	Type
status	zx/status
features	uint32

Describe

Returns extra information about the type of the object. If the Describe operation fails, the connection is closed.

This method does not require any rights.

Request

<EMPTY>

Response

Name	Type
info	fuchsia.io/NodeInfo

Describe2

Returns extra connection information and auxiliary handles.

• query specifies the fields in ConnectionInfo that the caller is interested in.

• info see fuchsia.io2/ConnectionInfo for details on the fields.

When all known bits in query are set, the return value matches the one from OnConnectionInfo, as if the caller requested that event using ConnectionFlags.GET_CONNECTION_INFO.

If the Describe operation fails, the connection is closed with the associated error.

This method does not require any rights.

Request

Name	Type
query	fuchsia.io/ConnectionInfoQuery

Response

Name	Type
info	fuchsia.io/ConnectionInfo

GetAttr

Acquires information about the node.

This method does not require any rights.

Request

<EMPTY>

Response

Name	Type
s	zx/status
attributes	fuchsia.io/NodeAttributes

GetAttributes

Acquires information about the node.

The attributes of a node should be stable, independent of the specific protocol used to access it.

• query a bit-mask specifying which attributes to fetch. The server should not return more than necessary.

• attributes the returned attributes.

This method requires the Rights.GET_ATTRIBUTES right.

Request

Name	Type
query	fuchsia.io/NodeAttributesQuery

Response

Name	Type
result	fuchsia.io/Node_GetAttributes_Result

GetBackingMemory

Acquires a zx.handle:VMO representing this file, if there is one, with the requested access rights.

• request flags a VmoFlags indicating the desired mode of access.

• response vmo the requested zx.handle:VMO.

• error a zx.status value indicating the failure.

This method requires the following rights:

• Rights.READ_BYTES if flags includes VmoFlags.READ.
• Rights.WRITE_BYTES if flags includes VmoFlags.WRITE.
• Rights.EXECUTE if flags includes VmoFlags.EXECUTE.

Request

Name	Type
flags	fuchsia.io/VmoFlags

Response

Name	Type
result	fuchsia.io/File_GetBackingMemory_Result

GetBuffer

Acquires a buffer representing this file, if there is one, with the requested access rights.

flags may be any of VMO_FLAG_*.

This method requires following rights:

• OPEN_RIGHT_WRITABLE if flags includes VMO_FLAG_WRITE.
• OPEN_RIGHT_READABLE if flags includes VMO_FLAG_READ or VMO_FLAG_EXEC.
• OPEN_RIGHT_EXECUTABLE if flags includes VMO_FLAG_EXEC.

Request

Name	Type
flags	uint32

Response

Name	Type
s	zx/status
buffer	fuchsia.mem/Buffer?

GetFlags

Acquires the Directory.Open rights and flags used to access this file.

This method does not require any rights.

Request

<EMPTY>

Response

Name	Type
s	zx/status
flags	uint32

GetWindowSize

Obtain the window size (in character cells)

Request

<EMPTY>

Response

Name	Type
status	zx/status
size	WindowSize

IoToIo2Placeholder

This message should never be sent or received.

This declaration exists to let keep the Rust bindings compiling as we add and remove transitional elements from the fuchsia.io protocols. Without this declaration, the users of the Rust bindings fail to compile when there aren't any transitional protocol elements.

DEPRECATED

Request

<EMPTY>

MakeActive

allowed on the Controlling PTY

Select which Client PTY receives input. Reads will simply block on non-active PTYs.

Request

Name	Type
client_pty_id	uint32

Response

Name	Type
status	zx/status

NodeGetFlags

Acquires the Directory.Open rights and flags used to access this file.

This method does not require any rights. This method has the same functionality as GetFlags for File and is meant as an in-progress replacement.

Request

<EMPTY>

Response

Name	Type
s	zx/status
flags	uint32

NodeSetFlags

Changes the Directory.Open flags used to access the file. Supported flags which can be turned on / off:

• OPEN_FLAG_APPEND

This method does not require any rights. This method has the same functionality as SetFlags for File and is meant as an in-progress replacement.

Request

Name	Type
flags	uint32

Response

Name	Type
s	zx/status

OnConnectionInfo

An event produced eagerly by the server if requested by ConnectionFlags.GET_CONNECTION_INFO. This event will be the first message from the server, and is sent exactly once.

• info See fuchsia.io2/ConnectionInfo for details on the fields. All members should be present.

Different from fuchsia.io/OnOpen, an error during open/reopen is always manifested as an epitaph.

Response

Name	Type
info	fuchsia.io/ConnectionInfo

OnOpen

An event produced eagerly by a FIDL server if requested by OPEN_FLAG_DESCRIBE.

Indicates the success or failure of the open operation, and optionally describes the object. If the status is ZX_OK, info contains descriptive information about the object (the same as would be returned by Describe).

Response

Name	Type
s	zx/status
info	fuchsia.io/NodeInfo?

OpenClient

Open a client PTY device with a unique id. client should be a handle to one endpoint of a channel that (on success) will become an open connection to the newly created device. On failure, the channel will be closed. Closing the channel will close the connection and release the device. If the provided id is 0, then the new client is a controlling client and has the capability to open additional clients. If the current device is not a controlling client, ZX_ERR_ACCESS_DENIED will be returned. If id is not unique, ZX_ERR_INVALID_ARGS will be returned. Otherwise the status code from device_add is passed on.

Request

Name	Type
id	uint32
client	request<Device>

Response

Name	Type
s	zx/status

Read

Reads up to count bytes at the seek offset. The seek offset is moved forward by the number of bytes read.

This method requires the following rights: OPEN_RIGHT_READABLE, otherwise returns ZX_ERR_BAD_HANDLE.

Returns ZX_ERR_OUT_OF_RANGE if count is greater than MAX_BUF.

Request

Name	Type
count	uint64

Response

Name	Type
s	zx/status
data	vector<uint8>[8192]

Read2

Reads up to 'count' bytes at the seek offset. The seek offset is moved forward by the number of bytes read.

Invariants

• The returned data.length will never be greater than count.
• If data.length is less than count, it means that the seek offset has reached the end of file as part of this operation.
• If data.length is zero while count is not, it means that the seek offset is already at or beyond the end of file, and no data could be read.
• If count is zero, the server should perform all the checks ensuring read access without actually read anything, and return an empty data vector.

This method requires the Rights.READ_BYTES right.

Returns ZX_ERR_OUT_OF_RANGE if count is greater than MAX_TRANSFER_SIZE.

Request

Name	Type
count	uint64

Response

Name	Type
result	fuchsia.io/File_Read2_Result

ReadAt

Reads up to count bytes at the provided offset. Does not affect the seek offset.

This method requires the following rights: OPEN_RIGHT_READABLE, otherwise returns ZX_ERR_BAD_HANDLE.

Returns ZX_ERR_OUT_OF_RANGE if count is greater than MAX_BUF.

Request

Name	Type
count	uint64
offset	uint64

Response

Name	Type
s	zx/status
data	vector<uint8>[8192]

ReadAt2

Reads up to 'count' bytes at the provided offset. Does not affect the seek offset.

Invariants

• The returned data.length will never be greater than count.
• If data.length is less than count, it means that ReadAt has hit the end of file as part of this operation.
• If data.length is zero while count is not, it means that offset is at or past the end of file, and no data can be read.
• If count is zero, the server should perform all the checks ensuring read access without actually reading anything, and return an empty data vector.

This method requires the Rights.READ_BYTES right.

Returns ZX_ERR_OUT_OF_RANGE if count is greater than MAX_TRANSFER_SIZE.

Request

Name	Type
count	uint64
offset	uint64

Response

Name	Type
result	fuchsia.io/File_ReadAt2_Result

ReadEvents

Returns pending OOB events, simultaneously clearing them

Request

<EMPTY>

Response

Name	Type
status	zx/status
events	uint32

Reopen

Creates another connection to the same node.

• options options applicable to both Open and Reopen, including negotiating protocol and restricting rights. See fuchsia.io2/ConnectionOptions.
• object_request is the server end of a channel created for the new connection. The caller may proceed to send messages on the corresponding client end right away.

For files, the cloned connection and the original connection have independent seek offsets.

Request

Name	Type
options	fuchsia.io/ConnectionOptions
object_request	handle<channel>

Resize

Shrinks or grows the file size to 'length' bytes.

If file size is reduced by this operation, the extra trailing data' is discarded. If file size is increased by this operation, the extended area appears as if it was zeroed.

This method requires the Rights.WRITE_BYTES right.

Request

Name	Type
length	uint64

Response

Name	Type
result	fuchsia.io/File_Resize_Result

Seek

Moves the offset at which the next invocation of Read() or Write() will occur.

This method does not require any rights.

Request

Name	Type
offset	int64
start	fuchsia.io/SeekOrigin

Response

Name	Type
s	zx/status
offset	uint64

Seek2

Moves the offset at which the next invocation of Read or Write will occur. The seek offset is specific to each file connection.

• request origin the reference point where offset will be based on.
• request offset the number of bytes to seek.

• response offset_from_start the adjusted seek offset, from the start of the file.

This method does not require any rights.

Request

Name	Type
origin	fuchsia.io/SeekOrigin
offset	int64

Response

Name	Type
result	fuchsia.io/File_Seek2_Result

SetAttr

Updates information about the node. flags may be any of NODE_ATTRIBUTE_FLAG_*.

This method requires following rights: OPEN_RIGHT_WRITABLE, otherwise returns ZX_ERR_BAD_HANDLE.

Request

Name	Type
flags	uint32
attributes	fuchsia.io/NodeAttributes

Response

Name	Type
s	zx/status

SetFlags

Changes the Directory.Open flags used to access the file. Supported flags which can be turned on / off:

• OPEN_FLAG_APPEND

This method does not require any rights.

Request

Name	Type
flags	uint32

Response

Name	Type
s	zx/status

SetWindowSize

allowed on the Server PTY

Sets the window size

Request

Name	Type
size	WindowSize

Response

Name	Type
status	zx/status

Sync

Synchronizes updates to the node to the underlying media, if it exists.

This method does not require any rights.

Request

<EMPTY>

Response

Name	Type
s	zx/status

Sync2

Synchronizes updates to the node to the underlying media, if it exists.

This method will return when the filesystem server has flushed the relevant updates to the underlying media, but does not guarantee the underlying media has persisted the information, nor that any information is committed to hardware. Clients may use Sync to ensure ordering between operations.

This method does not require any rights.

Request

<EMPTY>

Response

Name	Type
result	fuchsia.io/Node_Sync2_Result

Truncate

Shrinks the file size to 'length' bytes.

This method requires following rights: OPEN_RIGHT_WRITABLE, otherwise returns ZX_ERR_BAD_HANDLE.

Request

Name	Type
length	uint64

Response

Name	Type
s	zx/status

UpdateAttributes

Updates information about the node.

• attributes the presence of a table field in attributes indicates the intent to update the corresponding attribute.

This method requires the Rights.UPDATE_ATTRIBUTES right.

Request

Name	Type
attributes	fuchsia.io/NodeAttributes2

Response

Name	Type
result	fuchsia.io/Node_UpdateAttributes_Result

Write

Writes data at the seek offset. The seek offset is moved forward by the number of bytes written.

This method requires following rights: OPEN_RIGHT_WRITABLE, otherwise returns ZX_ERR_BAD_HANDLE.

Request

Name	Type
data	vector<uint8>[8192]

Response

Name	Type
s	zx/status
actual	uint64

Write2

Writes data at the seek offset. The seek offset is moved forward by the number of bytes written. If the file is in append mode, the seek offset is first set to the end of the file, followed by the write, in one atomic step.

The file size may grow if the seek offset plus data.length is beyond the current end of file.

• request data the byte buffer to write to the file.

• response actual_count the number of bytes written.

Invariants

• The returned actual_count will never be greater than data.length.
• If the server is unable to write all the data due to e.g. not enough space, actual_count may be less than data.length.
• If data.length is zero, the server should perform all the checks ensuring write access without mutating the file. The seek offset is still updated if in append mode.

This method requires the Rights.WRITE_BYTES right.

Request

Name	Type
data	fuchsia.io/Transfer

Response

Name	Type
result	fuchsia.io/File_Write2_Result

WriteAt

Writes data to the provided offset. Does not affect the seek offset.

This method requires following rights: OPEN_RIGHT_WRITABLE, otherwise returns ZX_ERR_BAD_HANDLE.

Request

Name	Type
data	vector<uint8>[8192]
offset	uint64

Response

Name	Type
s	zx/status
actual	uint64

WriteAt2

Writes data at the provided offset. Does not affect the seek offset.

The file size may grow if offset plus data.length is past the current end of file.

• request data the byte buffer to write to the file.
• request offset the offset from start of the file to begin writing.

• response actual_count the number of bytes written.

Invariants

• The returned actual_count will never be greater than data.length.
• If the server is unable to write all the data due to e.g. not enough space, actual_count may be less than data.length.
• If data.length is zero, the server should perform all the checks ensuring write access without mutating the file.

This method requires the Rights.WRITE_BYTES right.

Request

Name	Type
data	fuchsia.io/Transfer
offset	uint64

Response

Name	Type
result	fuchsia.io/File_WriteAt2_Result

STRUCTS

WindowSize

Defined in fuchsia.hardware.pty/pty.fidl

Field	Type	Description	Default
width	uint32		No default
height	uint32		No default

CONSTANTS

Name	Value	Type	Description
EVENT_HANGUP	1	uint32	The terminal has no active client.
EVENT_INTERRUPT	2	uint32	The terminal received a ^C control character.
EVENT_MASK	7	uint32	All events
EVENT_SUSPEND	4	uint32	The terminal received a ^Z control character.
FEATURE_RAW	1	uint32	When Feature Raw is enabled, OOB Events like ^c, ^z, etc are not generated. Instead the character is read from the read() input path.
SIGNAL_EVENT	33554432	uint32	When an event is pending, this signal is asserted on the Controlling PTY.