wait statement in C-component?

Question

Is there a wait statement in c-component? for example, wait for 0.5 second before continuing the process?

thanks!

Answer 1

In POSIX there is

usleep(500);

and

nanosleep(...);

have a look at the manual of usleep(3) and nanosleep(2). EDIT: nanosleep seems now to be the way to go, usleep is even deprecated in POSIX.2008 according to its manpage!

Answer 2

For Windows there is this function available in the API

Sleep(500);

Have a look at its MSDN page. It sleeps for the specified amount of milliseconds.

Answer 3

Thanks all. I appreciate your help!

Answer 4

sleep is also available in POSIX, the difference is that argument specifies the number of Seconds instead of Milliseconds the process should sleep.

Answer 5

To summarize and correct a minor problem in Johannes Weiss' post (non-German keyboard, sorry):

In old-school POSIX, you could use the usleep() function, which accepts the number of microseconds to sleep as an unsigned integer argument. Thus, to sleep for half a second, you'd call:

#include <unistd.h>
usleep(500000); /* Five hundred thousand microseconds is half a second. */

For newer POSIX-style programs (my Gentoo Linux box' man pages says it's POSIX.1-2001), you'd use nanosleep(), which requires a pointer to a structure holding the period to sleep. Sleeping for half a second would look like this:

#include <time.h>
struct timespec t;
t.tv_sec = 0;
t.tv_nsec = 500000000; /* Five hundred million nanoseconds is half a second. */
nanosleep(&t, NULL); /* Ignore remainder. */

The second argument to nanosleep() is called "rem", and receives the remainder of the time, if the sleep is somehow interrupted. I left it at NULL for simplicity, here. You could do a loop until rem is (close enough to) zero, to make sure you really get your sleep, regardless of any interruptions.