Can't recognise khpun, khp functions...

Community Support
1

I’m using the new kdb package which downlaod from Github(https://github.co/KxSystems/kdb), it has the C API interface to convert data into K type.

While I write code in Visual Studio and try to compile it, there’re error message. Such as: can’t recognize khpun, khp function.

So I must made 

2

So I must made mistake. May I ask any advice that I can follow to check? Or are there special setting for Visual Studio(such as set lib, dll file path)?

3

Have you included the k.h header file in your code? 

There is a good whitepaper from  using the capi you can follow here

4

Thanks davidcrossey. I had included the k.h in my cpp file.

It seems khpun function in k.h can’t be invoked. 

5

Did you compile your code and link against the c.o object file too? Check out kdb/l64/c.o at master · KxSystems/kdb · GitHub If you need a different OS binary, check out the directories at the root of the repo.

More info here: C/C++ | Interfaces | kdb+ and q documentation - Kdb+ and q documentation (kx.com)

6

Thanks, My OS is Win10 64bit.

I’m reading the doc(https://code.kx.com/q/wp/capi/#creating-a-simple-list-object) and want to copy sample code into my Visual Studio env. But why I can’t find the “common.h” file? 

7

OK, I found it(https://github.com/kxcontrib/capi).

8

I did test based on the source code from Github, for example the portopen.c, common.h, k.h

But error message reports at my Visual Studio env: E0167 “const char *”   “S” 

Does the k.h works fine at Win10 64bit env?

9

Yes it can be used on w64, however there are differences in terms of the libraries needed for linking: kdb/w64 at master · KxSystems/kdb (github.com)

This repo: kxcontrib/capi (github.com) only supports Linux based environments. You could fork it and add Windows support yourself, or a more straight forward solution would be to setup WSL2 with a *nix distribution (such as Ubuntu), and use that environment for your local development - works with VS Code.

10

It took me 2 days but still failed. I have to use the old version(the old k.h and c.obj) with the same code I wrote, it works fine. So I doubt there’re bug or something I don’t know that caused the issue.