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#include "kernel/types.h"
#include "user/user.h"
#define MAX 36
#define FIRST_PRIME 2
int
generate_natural(); // -> out_fd
int
prime_filter(int in_fd, int prime); // -> out_fd
int
main(int argc, char* argv[])
{
int prime;
int in = generate_natural();
while (read(in, &prime, sizeof(int))) {
// printf("prime %d: in_fd: %d\n", prime, in); // debug
printf("prime %d\n", prime);
in = prime_filter(in, prime);
}
close(in);
exit(0);
}
int
generate_natural()
{
int out_pipe[2];
pipe(out_pipe);
if (!fork()) {
for (int i = FIRST_PRIME; i < MAX; i++) {
write(out_pipe[1], &i, sizeof(int));
}
close(out_pipe[1]);
exit(0);
}
close(out_pipe[1]);
return out_pipe[0];
}
int
prime_filter(int in_fd, int prime)
{
int num;
int out_pipe[2];
pipe(out_pipe);
if (!fork()) {
while (read(in_fd, &num, sizeof(int))) {
if (num % prime) {
write(out_pipe[1], &num, sizeof(int));
}
}
close(in_fd);
close(out_pipe[1]);
exit(0);
}
close(in_fd);
close(out_pipe[1]);
return out_pipe[0];
}
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