how to read xlsx files using C

Question

Part of my school project I need to work with LabWindows/CVI.

I need to read a xlsx file and analize it.

I download this libxl library.

I amported the h files and the lib files. this is my code ( I coppied it from here):

#include <cvirte.h>     
#include <userint.h>
#include <formatio.h>
#include "Final work.h"
#include "libxl.h"


////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

static int panelHandle;

int readFile()
{
    BookHandle book = xlCreateBook(); // xlCreateXMLBook()
    if (xlBookLoad(book, "G:/Electro data/0.5_time_all.xlsx")){
        return 0;   
    }
    if(book) 
    {
        SheetHandle sheet = xlBookAddSheet(book, L"Sheet1", 0);
        if(sheet) 
        {
            xlSheetWriteStr(sheet, 2, 1, L"Hello, World !", NULL);
            xlSheetWriteNum(sheet, 3, 1, 1000, NULL);
        }
        xlBookSave(book, L"example.xls");
        xlBookRelease(book);
    }
    
    return 0;
}

and I am getting this errors: Build Status (Final work.prj - Debug) Final work.c - 3 warnings

error: Undefined symbol '_xlBookAddSheetA' referenced in "c:\Users\USER\Documents\National Instruments\CVI\cvibuild.Final work\Debug\Final work.obj".

error: Undefined symbol '_xlBookLoadA' referenced in "c:\Users\USER\Documents\National Instruments\CVI\cvibuild.Final work\Debug\Final work.obj".

error: Undefined symbol '_xlBookReleaseA' referenced in "c:\Users\USER\Documents\National Instruments\CVI\cvibuild.Final work\Debug\Final work.obj".

error: Undefined symbol '_xlBookSaveA' referenced in "c:\Users\USER\Documents\National Instruments\CVI\cvibuild.Final work\Debug\Final work.obj".

error: Undefined symbol '_xlCreateBookCA' referenced in "c:\Users\USER\Documents\National Instruments\CVI\cvibuild.Final work\Debug\Final work.obj".

error: Undefined symbol '_xlSheetWriteNumA' referenced in "c:\Users\USER\Documents\National Instruments\CVI\cvibuild.Final work\Debug\Final work.obj".

error: Undefined symbol '_xlSheetWriteStrA' referenced in "c:\Users\USER\Documents\National Instruments\CVI\cvibuild.Final work\Debug\Final work.obj".

Build failed.

here is an image to illustrate:

What am I doing wrong?

IDK, but they are linker errors. However you should fix the three compiler warnings concerning passing incompatible pointer types to functions: `unsigned short []` to `const char*`. Presumably due to the `L` in `L"Sheet1"` which judging from the warning message can be just `"Sheet1"`. — Weather Vane, Feb 29 '20 at 15:35
Unrelated to your problem, but most probably wrong: If `xlBookLoad()` returns `true`, it was successful. But you quit the function. And you didn't check that `book` contains a valid handle before that `if`. — the busybee, Feb 29 '20 at 15:54

score 1 · Accepted Answer · answered Feb 29 '20 at 15:50

1

You need to link with the provided library. From the screenshot you seem to have added the library to your project, however the linker does not get it.

answered Feb 29 '20 at 15:50

the busybee

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how to read xlsx files using C

1 Answers1