Question

Two questions:

1. How to quickly clear an array of a structure?
2. How to free memory allocated by the structure’s member?

Code:

struct sComputerNames
{
    TCHAR *sName;   // Using a pointer here to minimize stack memory.   
};

TCHAR *sComputer  = (TCHAR *) calloc(2048+1, sizeof(TCHAR));
struct sComputerNames sCN[4096] = {0};


_tcscpy(sComputer,L"PC1");
sCN[0].sName = (TCHAR *) calloc(128,sizeof(TCHAR));
_tcscpy_s(sCN[0].sName,128,sComputer);


// What is a better way to clear out the structure array?
for (DWORD i=0;i<4096;i++)
{
    free(sCN[i].sName);
    sCN[i].sName=NULL;
}


// Assign a new value
_tcscpy(sComputer,L"PC2");
sCN[0].sName = (TCHAR *) calloc(128,sizeof(TCHAR));
_tcscpy_s(sCN[0].sName,128,sComputer);


free(sCN);sCN=NULL;     // Erroring here - how to free memory allocated by sCN's members?
free(sComputer);sComputer=NULL;

Thank you!

Answer 1

Clearing the array is easy:

memset(sCN, 0, sizeof(sCN));

As for the rest, you have some confusion about trying to free sCN which you didn’t malloc(), and trying to free lots of names when you only calloc()’d one of them.