SNAX/HLS Application Programming Manual

SCOBOLX Applications
SNAX/HLS Programming Standards
1–8 104707 Tandem Computers Incorporated
Server and terminal
Interfaces
The server and terminal interfaces are described below.
Server Interface
If SNAX/HLS is accessed through the server interface, you issue requests to
SNAX/HLS using the SEND statement. For example, to issue an OPEN-SESSION
request, your program might look as follows:
(Statements to prepare the text
in the OPEN-SESSION-REQUEST
structure)
MOVE verb-open-session
TO verb-code OF request-header.
SEND request-header open-session-request TO your-server
REPLY CODE verb-open-session YIELDS
reply-header open-session-reply.
Note the use of the SEND verb. In this case, the message consists of the request-
header and the body of the open-session request. The interpretation of the reply
depends on the value returned in the verb code (first integer) of the reply. In many
cases, your program must provide for all possible replies.
Terminal Interface
If SNAX/HLS is accessed from your SCOBOLX program through the Intelligent
Device Support (IDS), you use the SEND MESSAGE verb to issue requests to
SNAX/HLS. In addition, you can specify a time limit and allow for unsolicited
messages. If you enable these features, as described below, your SEND MESSAGE
operation completes normally or with an error, depending upon whether the enabled
event (that is, timeout or unsolicited message arrival) occurred and precisely when it
occurred in relation to the normal SNAX/HLS completion. Therefore, your program
should be prepared to handle not only normal terminations, but also error
terminations.
The SCOBOLX features of timeout and escape on unsolicited messages are supported
only on the terminal interface. The unsolicited message feature is not supported on
the server interface, and the timeout feature uses the CANCEL request on the server
interface. Note that the use of CANCEL can easily result in loss of data.