trailnul.c

#include <sys/socket.h>
#include <sys/types.h>
#include <sys/un.h>
#include <stdio.h>
#include <string.h>

#define LEN_B 15
#define LEN_C 16

int main() {
	struct sockaddr_un a;
	int b, c;
	size_t sb, sc;

	b = socket(AF_UNIX, SOCK_STREAM, 0);
	c = socket(AF_UNIX, SOCK_STREAM, 0);
	sb = &a.sun_path[LEN_B] - (char*)&a;
	sc = &a.sun_path[LEN_C] - (char*)&a;
	memset(&a, 0, sizeof(a));
	a.sun_family = AF_UNIX;
	if (0 != bind(b, (struct sockaddr*)&a, (socklen_t)sb)) {
		perror("bind");
		return 1;
	}
	if (0 != listen(b, SOMAXCONN)) {
		perror("listen");
		return 1;
	}
	if (0 != connect(c, (struct sockaddr*)&a, (socklen_t)sc)) {
		perror("connect");
		return 1;
	}
	return 0;
}