HTTP Client in C

httpclient.c

#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netdb.h>
#include <errno.h>

#define GNU_SOURCE
#include <signal.h>
#include <poll.h>


int main(void)
{
	struct addrinfo hints;
	struct addrinfo *result, *rp;
	int sfd;
	int s;
	char buff[4];
	int nread;
	struct timespec timeout;
	struct pollfd pfd;
	const char *command = "GET / HTTP/1.0\n\n";
	
	memset(&hints, 0, sizeof(struct addrinfo));
	hints.ai_family = AF_UNSPEC;
	hints.ai_socktype = SOCK_STREAM;
	
	s = getaddrinfo("www.yahoo.co.jp", "http", &hints, &result);
	if(s != 0){
		fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(s));
		return -1;
	}

	for(rp = result; rp != NULL; rp = rp->ai_next){
		sfd = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
		if(sfd == -1) continue;

		if(connect(sfd, rp->ai_addr, rp->ai_addrlen) != -1)
			break;

		close(sfd);
	}
	
	freeaddrinfo(result);

	if(rp == NULL){
		fprintf(stderr, "Connection Failer\n");
		return -1;
	}

	send(sfd, command, strlen(command), 0);

	timeout.tv_sec = 0;
	timeout.tv_nsec= 100*1000*1000; /* 100ms */
	pfd.fd = sfd;
	pfd.events = POLLIN;

	while(1){
		ppoll(&pfd, 1, &timeout, NULL);
		nread = recv(sfd, buff, sizeof(buff), 0);
		if(nread == -1){
			perror("read");
			close(sfd);
			return -1;
		}
		if(nread == 0)
			break;
		buff[nread] = '\0';
		printf(buff);
	}
	return 0;
}