spinny.c

#include <stdio.h>
#include <unistd.h>

int main(void) {
  setbuf(stdout, NULL);
  char *c = "\\-/|";
  for (int i = 0; i < 4; i = (i == 3) ? 0 : i + 1) {
    putc(c[i], stdout);
    usleep(12000);
    putc('\r', stdout);
  }
}