Jagged String Array (VC++) Sample

main.cpp

#include <tchar.h>
#include <stdio.h>
#include <combaseapi.h>

int __stdcall GetStringArrayDataW(OUT LPWSTR** lpArrayDest, OUT SIZE_T* pArrayLength);
void __stdcall FreeStringArrayW(OUT LPWSTR** lpArrayDest, IN SIZE_T nArrayLength);

int __stdcall GetStringArrayDataA(OUT LPSTR** lpArrayDest, OUT SIZE_T* pArrayLength);
void __stdcall FreeStringArrayA(OUT LPSTR** lpArrayDest, IN SIZE_T nArrayLength);

#ifdef UNICODE
    #define GetStringArrayData GetStringArrayDataW
    #define FreeStringArray FreeStringArrayW
#else // UNICODE
    #define GetStringArrayData GetStringArrayDataA
    #define FreeStringArray FreeStringArrayA
#endif // UNICODE

int main() {
    LPTSTR* lpArray;
    SIZE_T len;
    
    if (!GetStringArrayData(&lpArray, &len)) {
        return (-1);
    }
    for (SIZE_T i = 0; i < len; i++) {
        _ftprintf(stdout, _T("[%d] %s\r\n"), i, lpArray[i]);
    }

    FreeStringArray(&lpArray, len);
    return 0;
}

static const SIZE_T nStringLength = 32;
static const SIZE_T nArraySize = 8;

int __stdcall GetStringArrayDataW(OUT LPWSTR** lpArrayDest, OUT SIZE_T* pArrayLength) {
    *pArrayLength = nArraySize;
    LPWSTR* lpArray = (LPWSTR*)CoTaskMemAlloc(nArraySize * sizeof(LPWSTR));
    if (!lpArray) {
        return 0;
    }

    for (SIZE_T i = 0; i < nArraySize; i++) {
        lpArray[i] = (LPWSTR)CoTaskMemAlloc((nStringLength + 1) * sizeof(WCHAR));
        if (!lpArray[i]) {
            return i;
        }
        swprintf_s(lpArray[i], nStringLength + 1,
            L"%d%c%c%c%c", i, 'a' + i, 'a' + i, 'a' + i, 'a' + i);
    }

    *lpArrayDest = lpArray;
    return nArraySize;
}

void __stdcall FreeStringArrayW(OUT LPWSTR** lpArrayDest, IN SIZE_T nArrayLength) {
    LPWSTR* lpArray = *lpArrayDest;
    if (!lpArray) return;

    for (SIZE_T i = 0; i < nArrayLength; i++) {
        if (!lpArray[i]) continue;
        CoTaskMemFree(lpArray[i]);
        lpArray[i] = NULL;
    }

    CoTaskMemFree(lpArray);
    lpArray = NULL;
}

int __stdcall GetStringArrayDataA(OUT LPSTR** lpArrayDest, OUT SIZE_T* pArrayLength) {
    *pArrayLength = nArraySize;
    LPSTR* lpArray = (LPSTR*)CoTaskMemAlloc(nArraySize * sizeof(LPSTR));
    if (!lpArray) {
        return 0;
    }

    for (SIZE_T i = 0; i < nArraySize; i++) {
        lpArray[i] = (LPSTR)CoTaskMemAlloc((nStringLength + 1) * sizeof(CHAR));
        if (!lpArray[i]) {
            return i;
        }
        sprintf_s(lpArray[i], nStringLength + 1,
            "%d%c%c%c%c", i, 'a' + i, 'a' + i, 'a' + i, 'a' + i);
    }

    *lpArrayDest = lpArray;
    return nArraySize;
}

void __stdcall FreeStringArrayA(OUT LPSTR** lpArrayDest, IN SIZE_T nArrayLength) {
    LPSTR* lpArray = *lpArrayDest;
    if (!lpArray) return;

    for (SIZE_T i = 0; i < nArrayLength; i++) {
        if (!lpArray[i]) continue;
        CoTaskMemFree(lpArray[i]);
        lpArray[i] = NULL;
    }

    CoTaskMemFree(lpArray);
    lpArray = NULL;
}