problems with time function !!

I have written a simple code using time function... here I am having some undesired output.

I am copying the code for reference:

#include <stdio.h>
#include <time.h>
#include <sys/time.h>
 
void main(void)
{   time_t t1;
    time_t t2;
    struct timeval tv;
    int i=0;
    t1 = time(;NULL);
    printf("*******T1 = %ld\n\n",t1);
    for(i;i<100000;i++);
    for(i;i>0;i--);
    t2 = time(NULL);
    printf("********T2 = %d\n\n\n",t2);
    tv.tv_sec = difftime(t2,t1);
    printf("***The time difference is %ld",tv.tv_sec);
    exit();
}

The output is:

********T1 = 1128099984
 
 
 ********T2 = 1128099984
 
*** The time differene is : 0
\n

Therefore in both the cases time(NULL) is returning the same value. Do I need to use some other function to record the current time?

Pls suggest something !!! thanks, panther

you could also use "gettimeofday", it will return seconds AND microseconds.

robert

There are many issues with your code....to start with... you should not use

void main(void)

...it should be

int main(void)

...secondly, make variable i as long instead of int and try increasing the limit of in for loop to 100000000 or to even higher value ....you will notice a time difference