Is there any memory leakeage in this code?

Question

I have this code:

 int tim=10000; // some random number
 tm *now=localtime(&tim);
 printf("Date is %d/%02d/%02d\n", now->tm_year+1900, now->tm_mon+1, now->tm_mday);
 printf("Time is %02d:%02d\n", now->tm_hour, now->tm_min);

The reason that I am wondering if it has memory leak is that localtime returns a pointer to a struct which means that it allocate memory. but nobody release it.

Is there any memory leak on this code?

Answer 1

You don't (and shall not) have to explicitly free anything as localtime returns a pointer to a static object.

C Standard says:

(C11, 7.27.3 Time conversion functions p1) "Except for the strftime function, these functions each return a pointer to one of two types of static objects: a broken-down time structure or an array of char."

And from POSIX.1-2008 documentation,

The asctime(), ctime(), gmtime(), and localtime() functions shall return values in one of two static objects: a broken-down time structure and an array of type char. Execution of any of the functions may overwrite the information returned in either of these objects by any of the other functions.