#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <sys/wait.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>
#include <fcntl.h>
#include <libguile.h>

static void *main_parent(void *arg)
{
	int sv = *((int *) arg);
	SCM port;
	char *buf = "Write from parent\n";

	printf("Parent sv:%d\n", sv);

	port = scm_fdopen(scm_from_int(dup(sv)), scm_from_utf8_stringn("r+", 2));
	scm_c_write(port, buf, sizeof(buf));
}

static void *main_child(void *arg)
{
	int sv = *((int *) arg);
	SCM port;
	char *buf = "                 \n";

	printf("Child sv:%d\n", sv);

	port = scm_fdopen(scm_from_int(dup(sv)), scm_from_utf8_stringn("r+", 2));
	scm_c_read(port, buf, sizeof(buf));
	printf("%s\n", buf);
}

int main(int argc, char *argv[])
{
	pid_t id;
	int sv[2];

	if (socketpair(AF_UNIX, SOCK_DGRAM, 0, sv) != 0) {
		fprintf(stderr, "%s", strerror(errno));
		return EXIT_FAILURE;
	}

	id = fork();
	if (id == -1) {
		fprintf(stderr, "%s", strerror(errno));
		return EXIT_FAILURE;
	}

	if (id == 0) {
		/* parent process */
		scm_with_guile(main_parent, &sv[0]);
	} else {
		/* child process */
		scm_with_guile(main_child, &sv[1]);
	}
	wait(NULL);
	return EXIT_SUCCESS;
}