Guardian Procedure Calls Reference Manual (G06.25+)

Guardian Procedure Calls (C)
Guardian Procedure Calls Reference Manual—522629-013
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CONTROLBUF Procedure
is the number of an open file. It identifies the file on which the CONTROLBUF
procedure performs an I/O operation.
operation input
INT:value
is a value defined by the device, such as:
1 = Load DAVFU (printer subtype 4)
buffer input
INT:ref:*
is an array that contains the information to be used for the CONTROLBUF
operation.
count input
INT:value
is the number of bytes contained in
buffer.
count-transferred output
INT:ref:1
returns a count of the number of bytes transferred from
buffer (for wait I/O only).
tag input
INT(32):value
is for nowait I/O only. The
tag parameter is a value you define that uniquely
identifies the operation associated with this CONTROLBUF call.
Condition Code Settings
< (CCL) indicates that an error occurred (call FILE_GETINFO_ or FILEINFO).
= (CCE) indicates that the CONTROLBUF was successful.
> (CCG) for a process file, indicates that the process is not accepting process
CONTROLBUF messages.
Considerations
•
Wait and count-transferred
Note. The system stores the tag value until the I/O operation completes. The system then
returns the tag information in the tag parameter of the call to AWAITIO, thus indicating that
the operation finished.