how to sleep in c

Question

Possible Duplicate:
Why does printf not flush after the call unless a newline is in the format string?

When I run something like

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

then what I would expect is one dot per second ten times. What I get is ten dots once after ten seconds. Why is that so, and how do I get the program to actually print one point (or do other things) each second (or different time interval)?

_how to sleep in c_ ? Try `for (int i = 0; i < big_number; i++) ;` and disable optimization. I have production code here (not mine) that actually does that ^_^ — Bitterblue, Apr 15 '14 at 10:18

score 11 · Accepted Answer · answered Nov 14 '12 at 19:29

11

The printf() is buffering the data, you can force it to flush that data with fflush(stdout):

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

answered Nov 14 '12 at 19:29

Mike

40,613
26
100
171

thats what i thought... just didnt know about fflush() thanks :) – foaly Nov 14 '12 at 19:29

how to sleep in c

1 Answers1

Linked