C++ – How to Delay Execution by 1 Second

So I am trying to program a simple tick-based game. I write in C++ on a linux machine. The code below illustrates what I'm trying to accomplish.

for (unsigned int i = 0; i < 40; ++i)
{
    functioncall();
    sleep(1000); // wait 1 second for the next function call
}

Well, this doesn't work. It seems that it sleeps for 40 seconds, then prints out whatever the result is from the function call.

I also tried creating a new function called delay, and it looked like this:

void delay(int seconds)
{
    time_t start, current;

    time(&start);

    do
    {
        time(&current);
    }
    while ((current - start) < seconds);
}

Same result here. Anybody?