using free function after malloc

[bikashg]

Have written a function as follows....I am getting an error when I try to free the allocated memory through malloc...
Have put in a commment against the Free functions that are returning an error

Please HELP!

CString getLogFilename()
{
int x,temp;
char *yyyy = (char *)malloc(4);
char *mm = (char *)malloc(2);
char *dd = (char *)malloc(2);
char *zeroCat = (char *)malloc(2);
strcpy(zeroCat,"0");

CTime t = CTime::GetCurrentTime();

CString filename;

char appendDate[8];

/* get the year in yyyy format*/
x = t.GetYear();
_itoa(x,yyyy,10);

/* get the Month in mm format */
x = t.GetMonth();
_itoa(x,mm,10);
if(strlen(mm) == 1){
strcat(zeroCat,mm);
strcpy(mm,zeroCat);
strcpy(zeroCat,"0");
}


/* get the Day in dd format */
x = t.GetDay();
_itoa(x,dd,10);
if(strlen(dd) == 1){
strcat(zeroCat,dd);
strcpy(dd,zeroCat);
}

strcpy(appendDate,yyyy);
strcat(appendDate,mm);
strcat(appendDate,dd);

filename = appendDate;

free(yyyy); /*Error */
free(mm); /*Error */
free(dd); /*Error */
free(zeroCat); /*Error */
free(appendDate); /*Error */

return filename;
}

[Yves M]

First of all, you have to allocate n + 1 chars for a string of length n, because of the trailing 0 meaning end of string.

[Alexey B]

You have not allocated the memory for appendDate with malloc - that is the cause of the crush. You should have used static arrays instead of dynamic memory allocation as it is inappropriate here.

[bikashg]

Originally posted by Yves M
First of all, you have to allocate n + 1 chars for a string of length n, because of the trailing 0 meaning end of string.

Thanks Yves....it is working now.

Also is there a way of shortening the whole program using wsprintf ?

[bikashg]

Originally posted by Alexey B
You have not allocated the memory for appendDate with malloc - that is the cause of the crush. You should have used static arrays instead of dynamic memory allocation as it is inappropriate here.

yes Alexei...I have now fixed this problem..and it is working now thanks heaps

[Alexey B]

Also is there a way of shortening the whole program using wsprintf?

sscanf or CString::Format can shorten your code a great deal:

CString getLogFilename()
{
	CTime time = CTime::GetCurrentTime();
	CString filename;
	output.Format("%i/%i/%i", time.GetYear(), time.GetMonth(), time.GetDay());
	
	return filename;
}

[m_l]

you can try this way...

CString getLogFileName()
{
CString strFileName;
SYSTEMTIME st;

::GetLocalTime(st);

strFileName.Format(TEXT("%04d%02d%02d", st.wYear, st.wMonth, st.wDay);

return strFileName;
}

bye,
m_l

[billwilson3]

[QUOTE]quote:
--------------------------------------------------------------------------------
Also is there a way of shortening the whole program using wsprintf?
--------------------------------------------------------------------------------

sscanf or CString::Format can shorten your code a great deal:
code:--------------------------------------------------------------------------------CString getLogFilename()
{
CTime time = CTime::GetCurrentTime();
CString filename;
output.Format("%i/%i/%i", time.GetYear(), time.GetMonth(), time.GetDay());

return filename;
}
QUOTE]

Even simpler to use CTime::Format.

CString getLogFilename()
{
	CTime time = CTime::GetCurrentTime();
	CString filename = time.Format("%Y/%m/%d"); 	
	return filename;
}

[Alexey B]

inline CString getLogFilename()
{
	return CTime::GetCurrentTime().Format("%Y/%m/%d");
}