Display something every 3 seconds

Question

I can’t figure out how to display something (like hello world) every 3 seconds. I only write C programming with the gcc compiler in linux. We can stop it with Ctrl + c. I just want the simplest and easiest way to manipulate this code with my project.

Thank you so much in advance!

Answer 1

You may have a problem in the fact that standard output is usually buffered, which means that the implementation expands the output until it is convenient to write it. If you write every three seconds (and sleep(3)is a good way to do this) and it does not appear every three seconds, try inserting fflush(stdout);or writing to the standard error output using `fprintf (stderr," something \ n ");

Answer 2

while(1) {
    printf("something\n");
    sleep(3);
}

Answer 3

sleep(3);

sleep X . , , 3 , . , usleep, u , . . .

Answer 4

, (while (1) { ... }) .

, sleep . sleep, , nanosleep, .

#include <stdio.h>
#include <time.h>

int main()
{
  struct timespec t = { 3/*seconds*/, 0/*nanoseconds*/};
  while (1){
    printf("Wait three seconds and...\n");
    nanosleep(&t,NULL);
    fflush(stdout); //see below
  }
}

: (\n) outpu, , , , , ( , ). fflush.

Answer 5

, , , - - , n , /usr/bin/watch. .

Answer 6

setvbuf(). , , , (stdout) (stderr).

#include <stdio.h>

int main(int argc, char* argv[]) {
    setvbuf(stdout, NULL, _IONBF, 0);
    while ( 1 ) {
        printf("Wait 3 seconds... ");
        sleep(3);
    }
}

, \n printf. setvbuf(), , ( 1024 ).