Asynchronous Terminals and Printer Processes Programming Manual

SECTION 3
PROCEDURE CALLS FOR ACCESSING TERMINALS
This section describes the GUARDIAN 90 file-system procedure
calls that control interaction with terminals.
PROCEDURE CALLS SUMMARY
The following procedures perform input/output operations with
terminals. These procedures are documented in the System
Procedure Calls Reference Manual and the GUARDIAN Operating
System Programmer’s Guide . Some of the calls are described in
detail below the table.
AWAITIO waits for completion of an I/O operation
pending on an open file.
CANCELREQ cancels the oldest outstanding operation,
optionally identified by a tag, on an open file.
CLOSE stops access to an open file.
CONTROL is used for cursor control and modem connect and
disconnect. See Appendix B for a summary of
CONTROL operations.
DEVICEINFO returns device type and configured record length.
FILEINFO returns error information and characteristics
of a file.
OPEN starts access to a file.
READ reads information from an open file.
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