getaddrinfo.c

#include <stdio.h>

#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>


int main(int argc, char ** argv)
{
	static struct addrinfo hint = {
		.ai_flags = (0),
		.ai_family = AF_INET,
		.ai_socktype = SOCK_STREAM,
		.ai_protocol = 0,
		.ai_addrlen = 0,
		.ai_addr = NULL,
		.ai_canonname = NULL,
		.ai_next = NULL
	};

	while(1) {
		struct addrinfo * result;
		int ret;
		
		result = NULL;
		
		if(0 != (ret = getaddrinfo("localhost", NULL, &hint, &result)))
		{
			fprintf(stderr, "ERR: Failed on hostname to address translation: %s. @(%s:%d)\n", gai_strerror(ret), __FILE__, __LINE__);
			
			if(EAI_AGAIN == ret)
				sleep(3);
			else
				break;
		}
		else
		{
			if(NULL != result)
			{
				printf("R: %d\n", result->ai_addrlen);
				
				if(AF_INET == result->ai_addr->sa_family)
				{
					u_int32_t addr_v4;

					addr_v4 = ((struct sockaddr_in *)(result->ai_addr))->sin_addr.s_addr;

					printf("AF_INET = 0x%X\n", addr_v4);
				}

				freeaddrinfo(result);
				result = NULL;
			}
			else
			{
				printf("R: NULL\n");
			}
			
			break;
		}
	}
	
	return 0;
}


/*
vim: ts=4 sw=4 ai nowrap
*/