Thread: making a program expire

Hi all ... i was just wondering is there is a function that could be used in conjunction with a TM structure to get the system date and time? I am trying to make a program expire by using the below code in the constructor of a class. However i see no function that can fill this structure.

Code:

struct tm today;

//getdate(&today);  /* need a getdate function here */

if(today.tm_year > 1900)
{
	if(today.tm_mon > 6)
	{
	             cout << "Program Error ... Aborting!";
	             exit(1);
	}
}

Im using MSVC++ 6.0 ... thanks for any help

Right on ... thanks for the reply, ill give that a shot!

Hi again ... just had another question about making a program expire. After i have a TM for the time i want the program to expire, and a TM from the time() and localtime() functions. How would i convert these TM structures into a time_t type, so i could use the difftime() function on them ? Or would it be better to just compare the two TM structures to see if the one from the computer is past the expire TM ?

Code:

void CTest::programExpiration(void)
{
	double difference = 0;
	time_t systime;
	struct tm expire;
	expire.tm_mday = 10;
	expire.tm_mon  = 6;
	expire.tm_year = 2004;
	time(&systime);
	struct tm *today = localtime(&systime);

	//difference = difftime(today, expire);
}

Any help would be appreciated ... thanks again

yes i did try the mktime() function before, and it worked for the "struct tm *today" structure, however does nother for the "struct tm expire" structure. Is there a function that can convert a "struct tm" into a time_t type ?

:P

I tried that also, however the program crashes, and the difftime() return value is always the same no matter how i change the expire TM struct

Code:

void CMk3dpdek::programExpiration(void)
{
	double difference = 0;
	time_t systime, today_t, expire_t;
	struct tm expire;
	expire.tm_mday = 9;
	expire.tm_mon  = 6;
	expire.tm_year = 2004;
	time(&systime);
	struct tm *today = localtime(&systime);
	today_t  = mktime(today);
	expire_t = mktime(&expire);
	difference = difftime(today_t, expire_t);

	cout << endl << "THE DIFF IS : " << difference << endl;
	cout << endl << "TODAY TIME : " << ctime(&today_t);
	cout << endl << "EXPIRE TIME : " << ctime(&expire_t);
}

I think i see what you mean. So by getting the localtime() first then doing ...

Code:

struct tm expire = *today;

I guess that would be a "copy constructor" from one structure to another and make all the values the same.

But ya seems to work now thank you for all the help, guess i just have to add a if statement after the difftime() function and i can test it out.

Thanks again