最速 fizzbuzz に sendfile や tee を使おうと思ったけど、端末にはどちらも使えず pipe で cat とかに繋ぐ必要があって残念

basic.c

#include <stdio.h>
#include <stdlib.h>

void __attribute__((noinline)) fizzbuzz_basic (void){
	int i;
	for (i = 1; i <= 100; ++i) {
		if (i % 15 == 0) {
			printf("FizzBuzz\n");
		} else if (i % 3 == 0) {
			printf("Fizz\n");
		} else if (i % 5 == 0) {
			printf("Buzz\n");
		} else {
			printf("%d\n", i);
		}
	}
}

int main (int argc, char* argv[]) {
	int i, loop = 1;
	if (argc > 1) {
		loop = atoi(argv[1]);
	}
	fprintf(stderr, "Loops %d times\n", loop);

	for (i = 0; i < loop; ++i) {
		fizzbuzz_basic();
	}
	return 0;
}

pipe_and_tee.c

#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <unistd.h>
#include <fcntl.h>

static const char FIZZBUZZ_STRING[] =
"1\n2\nFizz\n4\nBuzz\nFizz\n7\n8\nFizz\nBuzz\n11\nFizz\n13\n14\nFizzBuzz\n16\n17\nFizz\n19\nBuzz\nFizz\n22\n23\nFizz\nBuzz\n26\nFizz\n28\n29\nFizzBuzz\n31\n32\nFizz\n34\nBuzz\nFizz\n37\n38\nFizz\nBuzz\n41\nFizz\n43\n44\nFizzBuzz\n46\n47\nFizz\n49\nBuzz\nFizz\n52\n53\nFizz\nBuzz\n56\nFizz\n58\n59\nFizzBuzz\n61\n62\nFizz\n64\nBuzz\nFizz\n67\n68\nFizz\nBuzz\n71\nFizz\n73\n74\nFizzBuzz\n76\n77\nFizz\n79\nBuzz\nFizz\n82\n83\nFizz\nBuzz\n86\nFizz\n88\n89\nFizzBuzz\n91\n92\nFizz\n94\nBuzz\nFizz\n97\n98\nFizz\nBuzz\n";

void __attribute__((noinline)) fizzbuzz_pipe (void){
	int pipe_fds[2];
	int ret = pipe(pipe_fds);
	if (ret < 0) {
		perror("pipe"); abort();
	}

	ret = write(pipe_fds[1], FIZZBUZZ_STRING, sizeof(FIZZBUZZ_STRING));
	if (ret < 0) {
		perror("write"); abort();
	} else if (ret < sizeof(FIZZBUZZ_STRING)) {
		fprintf(stderr, "too small\n"); abort();
	}
	close(pipe_fds[1]);


	/* char buf[16]; */
	/* read(pipe_fds[0], buf, sizeof(buf)); */
	/* write(STDOUT_FILENO, buf, sizeof(buf)); */
	ret = tee(pipe_fds[0], STDOUT_FILENO, INT_MAX, 0);
	if (ret < 0) {
		perror("tee"); abort();
	} else if (ret < sizeof(FIZZBUZZ_STRING)) {
		fprintf(stderr, "too small\n"); abort();
	}


	close(pipe_fds[0]);
}

int main (int argc, char* argv[]) {
	int i, loop = 1;
	if (argc > 1) {
		loop = atoi(argv[1]);
	}
	fprintf(stderr, "Loops %d times\n", loop);

	for (i = 0; i < loop; ++i) {
		fizzbuzz_pipe();
	}
	return 0;
}

sendfile.c

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/sendfile.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

const char FIZZBUZZ_FILE[] = "fizzbuzz.txt";
const int FIZZBUZZ_FILE_SIZE = 413;

void __attribute__((noinline)) fizzbuzz_sendfile (void){
	int in_fd = open(FIZZBUZZ_FILE, O_RDONLY);
	if (in_fd < 0) {
		perror("open"); abort();
	}

	/* char buf[16]; */
	/* int readcnt = read(in_fd, buf, sizeof(buf)); */
	/* int wrtcnt = write(STDOUT_FILENO, buf, sizeof(buf)); */

	int sent;
	do {
		sent = sendfile(STDOUT_FILENO, in_fd, NULL, 100);
		if (sent < 0) {
			perror("sendfile"); abort();
		}
	} while (sent > 0);

	close(in_fd);
}

int main (int argc, char* argv[]) {
	int i, loop = 1;
	if (argc > 1) {
		loop = atoi(argv[1]);
	}
	fprintf(stderr, "Loops %d times\n", loop);

	for (i = 0; i < loop; ++i) {
		fizzbuzz_sendfile();
	}
	return 0;
}

static_array.c

#include <stdio.h>
#include <stdlib.h>

static const char FIZZBUZZ_STRING[] =
"1\n2\nFizz\n4\nBuzz\nFizz\n7\n8\nFizz\nBuzz\n11\nFizz\n13\n14\nFizzBuzz\n16\n17\nFizz\n19\nBuzz\nFizz\n22\n23\nFizz\nBuzz\n26\nFizz\n28\n29\nFizzBuzz\n31\n32\nFizz\n34\nBuzz\nFizz\n37\n38\nFizz\nBuzz\n41\nFizz\n43\n44\nFizzBuzz\n46\n47\nFizz\n49\nBuzz\nFizz\n52\n53\nFizz\nBuzz\n56\nFizz\n58\n59\nFizzBuzz\n61\n62\nFizz\n64\nBuzz\nFizz\n67\n68\nFizz\nBuzz\n71\nFizz\n73\n74\nFizzBuzz\n76\n77\nFizz\n79\nBuzz\nFizz\n82\n83\nFizz\nBuzz\n86\nFizz\n88\n89\nFizzBuzz\n91\n92\nFizz\n94\nBuzz\nFizz\n97\n98\nFizz\nBuzz\n";

void __attribute__((noinline)) fizzbuzz_static_array (void){
	fputs(FIZZBUZZ_STRING, stdout);
}

int main (int argc, char* argv[]) {
	int i, loop = 1;
	if (argc > 1) {
		loop = atoi(argv[1]);
	}
	fprintf(stderr, "Loops %d times\n", loop);

	for (i = 0; i < loop; ++i) {
		fizzbuzz_static_array();
	}
	return 0;
}