Envoy Application Programming Manual

Table Of Contents
File-System Procedures
Envoy Application Programming Manual427159-001
C-35
WRITEREAD[X]
buffer input, output
INT:ref:* (Use with WRITEREAD)
STRING .EXT:ref:* (Use with WRITEREADX)
is the name of the integer array in the application program from which the outgoing
data is to be retrieved. The incoming data is subsequently placed there as well. The
buffer’s first two bytes contain the MCW.
write-count input
INT:value (Use with WRITEREAD and WRITEREADX)
specifies how many bytes are to be retrieved from the application buffer. You supply
this value to Envoy. Note that this value must include the two bytes used for the
MCW.
read-count input
INT:value (Use with WRITEREAD and WRITEREADX)
specifies how many incoming bytes are to be placed in the application buffer. You
supply this value to Envoy. Note that this value must include the two bytes used for
the MCW.
count-read output
INT:ref:1 (Use with WRITEREAD)
INT .EXT:ref:1 (Use with WRITEREADX)
is for wait I/O only. It returns a count of the number of bytes that Envoy actually
deposited into the application buffer. Note that this value, like the read-count, also
includes the two bytes used for the MCW.
tag input
INT(32):value (Use with WRITEREAD and WRITEREADX)
is for nowait I/O only. tag is a double-word integer value you supply; it uniquely
identifies the particular nowait WRITEREAD[X] call.
Condition Codes
< (CCL) Indicates that an error occurred (call FILEINFO).
= (CCE) Indicates that the WRITEREAD procedure was executed successfully.
> (CCG) Indicates that control-Y was struck on the terminal.