How to sleep in c

Question

Possible duplicate:
Why is printf not reset after a call if a new line is not specified in the format string?

When I run something like

for (i = 1; i <= 10; i++) { sleep(1); printf("."); } 

what I expect will be one dot per second ten times. What I get is ten points once every ten seconds. Why is this so, and how to make the program actually print one dot (or do other things) every second (or a different time interval)?

Answer 1

printf() performs data buffering, you can force reset this data using fflush(stdout) :

 for (i = 1; i<=10; i++) { sleep(1); printf("."); fflush(stdout); }