AutoCAD 2018: Unexpected Behavior Dealing with wchar_t

By Madhukar Moogala

Recently I had a request from an ADN partner troubleshooting a problem with reading values from a text file.

Assume we have a text file with following contents

Helloworld|Autodesk.

And, user would like to split string with pipe delimitation, so expected output would be

Helloworld and Autodesk.

#define wprintf acutPrintf
void readFile()
{
       const wchar_t  textFile[] = _T("C:\\Temp\\TFile\\helloworld.txt");
       FILE * pFile = NULL;
       wchar_t f1[20], f2[20];
       f1[0] = '\0'; f2[0] = '\0';

       if (_wfopen_s(&pFile, textFile, L"r") != 0 && pFile != NULL)
       {
             wprintf(L"failure opening file %s !\n", textFile);
             return;
       }
       /*
       %[^|] = store everything before '|' in place holder

       */
       while (fwscanf(pFile, L"%[^|]|%s\n", f1, f2) != EOF)
       {
             wprintf(L"I have read f1 as : %s  \n", f1);
             wprintf(L"I have read f2 as : %s  \n", f2);

       }
       fclose(pFile);
}

This gives garbage values in the placeholders, like shown in below pic

The root cause of this problem lies in the preprocess macro define

_CRT_STDIO_ISO_WIDE_SPECIFIERS =1

in ObjectARXSDK 2018\inc\rxsdk_common.props

To tackle issue with Visual Studio 2015, AutoCAD made a workaround, it is not a case anymore unfortunately this define lies in SDK and causing some other issues like I stated above.

You can remove this define from your SDK to avoid unnecessary issues while dealing with strings.