6530 Programmer's Guide

Tandem NonStop Kernel Application Interface
4-4
6530 Programmer’s Guide
Table 4-1. File System Procedure Calls
Procedure Function
AWAITIO Waits for completion of an outstanding I/O operation
pending on an open device.
CANCELREQ Cancels the oldest outstanding operation, optionally
identified by a tag, on an open device.
CLOSE Terminates access to an open device.
CONTROL Executes device-dependent operations on an open
device; used for forms control and modem connect/
disconnect.
DEVICEINF0 Provides the device type and physical record size
configured for a device (open or closed).
FILEINF0 Provides open device error and characteristics data.
GETDEVNAME Returns the $<device name> associated with a
logical device number if such a device exists;
otherwise, returns the name of the next higher
logical device.
OPEN Establishes a communications path to a device; first
searches the logical device table for the device and
then calls the I/O process that controls the device.
READ Reads information from an open device; transfers
data read to the application’s buffer.
SETMODE Sets/clears device-dependent functions for an open
device; for example, conversational or block mode,
parity checking, baud rate, etc.
SETMODENOWAIT Sets/clears device-dependent functions for an open
device in a no-wait manner.
WRITE Writes to an open device; transfers data to be
written from the application’s buffer to the device.
WRITEREAD Writes to an open device, then waits for date to be
returned (read) from the device.