I am writing some UDF's so that I can get at some of the flow data - not relevant right now.

To allow me to see how my UDF's are performing, I wanted to sprinkle the code with some printf statements.

Unfortuntaley the Printf doesn't seem to do anything.

I have now stripped the UDF right down to simply a few lines of Printf.

This works OK when interpreted but not when compiled. When I compile the UDF I don't seem to get any errors and it loads alright.

Anyone got any ideas?

Use "Message" or "CX_Message" (same syntax as printf) instead of "printf" for compiled udfs.

RoM

Thank you for this. Very helpful. I have also located some text in the fluent help file that refers to 'Message'. Strange thing is that it seems as though it should work (printf), in both interpreted and compiled mode.

I had a discussion with fluent suuport about this problem. The output from the fluent solver (written in c) to the cortex (scheme) is buffered and the message buffer needs to be fluhed bevor you will see the output in the cortex gui. The standard printf function wont do this, so fluent provides the Message macro. As far as i know, Message will work only in compiled udfs and not in interpreted mode.

RoM

On windows clients "printf" only works in interpreted mode. "Message" should work for both modes regardless of operating system.

The good old hello-world-udf will not run in interpreted mode on my WinXP machine.

#include "udf.h"

DEFINE_ON_DEMAND(hello)
{
Message("Hello world!\n");
}

The interpreter quits with
Error: C:\hello.c: line 7: function "CX_Message" not found (pc=5).

Compiling works fine though.

RoM

[Chunrong]

Originally Posted by RoM
;135315

The good old hello-world-udf will not run in interpreted mode on my WinXP machine.

#include "udf.h"

DEFINE_ON_DEMAND(hello)
{
Message("Hello world!\n");
}

The interpreter quits with
Error: C:\hello.c: line 7: function "CX_Message" not found (pc=5).

Compiling works fine though.

RoM

Hi RoM,

I got "Error code 126" when I used COMPLIED but okay for INTERPRETED. Do you know why it happened ? I tried to fix it by referring https://www.cfd-online.com/Forums/fluent/174350-udf-compilation-error-code-126-a.html but didn't work.

many thanks

[AlexanderZ]

reason of error code 126 is version mismatch

best regards

[Chunrong]

Hi AlexanderZ,

Very appreciate your reply. Since I don't own much knowledge about CS, can you explain it in details and what should I do to fix this error?

thanks and regards

[AlexanderZ]

in other thread you've mentioned, that you have both v19.0 and v.18.2 version of fluent.

Most likely you are compiling your UDF using one version, but run it with another.
Or you are not compiling library, because of some problems with compiler or code) and than try to read "bad" library, which was compiled long time ago for other fluent version

best regards