Programs doesn't end successfully

int main()
{
//create a socket
//connect to server
//send data to server
//recv data from server
//parse the data
IN the parse function "fill1.Total_hourmeter" get filled after parsing the data


//write parse the data into buffer
{
char buf_send[200];
    memset(buf_send,'\0', sizeof(buf_send));
strcpy(b_Total_hourmeter,fill1.Total_hourmeter);
    b_Total_hourmeter[8]='\0';

sprintf(buf_send,"%.2s",b_Total_hourmeter);
WriteToDataFile(buf_send);

}
#define BufferFilePath "C:\\Documents and Settings\\Administrator\\Desktop\\20sept_new\\20sept\\New_Nipro1\\NiproBuf.txt"
int WriteToDataFile(char* str)
{
    FILE* log;
    char    szDate[12];
        char    szTime[12];
    char buf_buf[2500];
    memset(buf_buf, 0, sizeof(buf_buf));
    _strdate( szDate );
        _strtime( szTime );
    sprintf(buf_buf,%s::%s:Info:%s, szDate, szTime, str);
    log = fopen(BufferFilePath,a+);
    if (log == NULL)
        return -1;
    fprintf(log,%s\n, buf_buf);
    fclose(log);
    return 0;
}

My function call is like this:-

struct a
{
char Total_hourmeter[8];
}fill1;
int main()
{
socket create
connect()/call
send call
recv call//
parse_recv_data(buffer)
{
//parsing

write_to_buffer()
return 0;
}

void write_to_buffer()
{
char b_Total_hourmeter[8];
char buf_send[200];
    memset(buf_send,'\0', sizeof(buf_send));
strcpy(b_Total_hourmeter,fill1.Total_hourmeter);
    b_Total_hourmeter[8]='\0';
WriteToDataFile(buf_send);

printf("");
}

void write_to_buffer()
{
....
WriteToDataFile(buf_send);
cin.ignore();
}