UPortDevice Struct Reference

The UPortDevice struct holds methods for a class of input/ouput device. More...

Data Fields
int(*	open )(UThread *, const UPortDevice *, const UCell *from, int opt, UCell *res)
	Create and open a new port.
void(*	close )(UBuffer *)
	Close port.
int(*	read )(UThread *, UBuffer *, UCell *, int len)
	Read data from port.
int(*	write )(UThread *, UBuffer *, const UCell *)
	Write data to port.
int(*	seek )(UThread *, UBuffer *, UCell *, int where)
	Seek to position.
int	defaultReadLen
	Number of bytes to read if script does not specify a length.

Detailed Description

The UPortDevice struct holds methods for a class of input/ouput device.

Field Documentation

close

void(* UPortDevice::close) (UBuffer *)

Close port.

Parameters

pbuf	Buffer created by UPortDevice::open.

defaultReadLen

int UPortDevice::defaultReadLen

Number of bytes to read if script does not specify a length.

This should be set to zero if UPortDevice::read does not expect a UT_BINARY or UT_STRING buffer.

open

int(* UPortDevice::open) (UThread *, const UPortDevice *, const UCell *from, int opt, UCell *res)

Create and open a new port.

Parameters

pdev	This device class.
from	Specification of port.
opt	Port options.
res	Cell for new port.

Returns

UR_OK/UR_THROW.

Open will normally call boron_makePort() to generate a port buffer and set res.

read

int(* UPortDevice::read) (UThread *, UBuffer *, UCell *, int len)

Read data from port.

If UPortDevice::defaultReadLen is greater than zero then dest will reference a UT_BINARY or UT_STRING buffer with enough memory reserved for len bytes.

Parameters

pbuf	Port buffer created by UPortDevice::open.
dest	Destination buffer or result.
len	Number of bytes to read into dest.

Returns

UR_OK/UR_THROW

seek

int(* UPortDevice::seek) (UThread *, UBuffer *, UCell *, int where)

Seek to position.

Parameters

pbuf	Buffer created by UPortDevice::open.
pos	New position relative to where.
where	SEEK_SET, SEEK_END, or SEEK_CUR.

Returns

UR_OK/UR_THROW

If the device cannot seek then call ur_error().

write

int(* UPortDevice::write) (UThread *, UBuffer *, const UCell *)

Write data to port.

Parameters

pbuf	Buffer created by UPortDevice::open.
data	Data to write.

Returns

UR_OK/UR_THROW

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The documentation for this struct was generated from the following files:

• boron.h
• boron_types.c