RE: Get name of current procdeure -- RPG400-L

I am trying to extract the receiver information using theReceive_Message (QMHRCVPM) API. I am specifing format RCVM0300 and myMessage_Text field is 1024 bytes. When I look at the Message_Text indebug, I only see the sending procedure name. The receiver name isnowhere to be found.

That's because when you display a data structure in the debugger, it listseach subfield of the data structure, with it's contents. You only haveONE SUBFIELD DEFINED, so it only shows that subfield! That subfield iscoded in the wrong place, so what you see is the wrong data.

If you (in teh green screen debugger) type "eval Message_text:x" on thecommand line, it'll show the whole data structure in hex. (rather than thesubfields)

So that's why you can't see the results in the debugger -- now on towhat's wrong with your code:

a) You have a variable called API_Error_Code that's defined as 144A andinitialized as *Blanks. You pass that as the error code parameter to thetwo APIs that you call. This is wrong. The APIs aren't expecting a biglong blank string as a parameter for the error code.

In fact, what they're expecting is a 4-byte binary integer containing thelength of the structure, followed by at least one other 4-byte binaryinteger.

Since blanks in EBCDIC are x'40', the first 4 bytes of your "error code"are x'40404040' -- convert that to decimal and you get 1077952576. That'show long the API thinks your error code data structure is! Over 1 gb!!

If it happens to try to write more than 144 bytes to it, it'll startcorrupting memory, and you'll end up with a really messed up environment.Why oh why did you think it was okay to pass a blank string to the API?

You have a definition called "Error_Ds" in your code that you're not using-- this definition is the correct one for calling these APIs -- EXCEPT --you're not inizializing the Bytes_Provided field. Since data structuresin RPG are all initialized to *blanks, this'll give you the same problemunless you add code to initialize the Bytes_provided field. Though, it's amoot point, since you're not passing it to the APIs anyway!

Even if you did pass it, you're not checking it after the API call, soeven if the API failed, you wouldn't know about it!

That's why my example had a data structure with two 10I 0 fields, bothinitialized to zero. If the API fails, and the Bytes_Provided field is 0,it'll send you an *ESCAPE message that you can catch in a *PSSR or MONITORstatement.

b) Your Message_Text variable is wrong. It should be a data structurecontaining a bunch of fields. Some of those fields are in variablepositions.


You can't just hard-code something in position 180.

The API sends some parameters that TELL YOU where the variable-lengthfields start and end. You can't just ignore what it tells you and assumethat it'll always be 180! That doesn't make sense.


That's why my code does the following:


       p_SndRcvInfo = %addr(RCVM0300.VarStart)
                    + RCVM0300.MsgDtaLen
                    + RCVM0300.MsgLen
                    + RCVM0300.MsgHlpLen;

Note that the SndRcvInfo data structure is BASED on the p_SndRcvInfopointer. When I add those fields together, I'm calculating the rightplace in memory to put that data structure. That way, I'm not justignoring what the API tells me for the position, but instead, I'm makingsure that the procedure name is extracted from the right place.


I hope this helps!