Exchange/RJE Manual

Step-by-Step Instructions
Using the Exchange/RJE Programmatic Interface
104698 Tandem Computers Incorporated 4–11
The line server is always opened for exclusive access regardless of the type of access
you specify in the call to OPEN. If your program attempts to open an existing line
server and that line server is being used by another program, the call to OPEN will fail
and return error number 12 (file in use). The only recovery in this case is to wait for
the other program to finish using the line server, unless your program can use a
different data communications line. If your program can use a different data
communications line, your program can open an existing line server that uses the
other line or start a new line server that uses the other line. Note that starting a new
line server that uses the same data communications line does not solve the problem
because an Exchange/RJE data communications line can be opened by only one line
server at a time.
Step 3: Send a Startup
Message to the Line Server
This step is only required if your program called the NEWPROCESS procedure to start
the line server.
Startup Message Structure
The structure of the required startup message is that of the standard startup message
passed by the operating system command interpreter to a new process. This structure
is described in the GUARDIAN Programmer’s Guide. The following TAL code
illustrates a typical startup message structure.
STRUCT .STARTMSG;
BEGIN
INT MSG^CODE;
STRUCT DEFAULT;
BEGIN
INT VOLUME[0:3];
SUBVOL[0:3];
END;
STRUCT INFILE;
BEGIN
INT VOLUME[0:3];
SUBVOL[0:3];
FNAME[0:3];
END;
STRUCT OUTFILE;
BEGIN
INT VOLUME[0:3];
SUBVOL[0:3];
FNAME[0:3];
END;
STRUCT PARAMS;
BEGIN
STRING BYTES[0: n ];
END;
END;
n is an integer value from 1 through 530.