用c语言实现http请求

用c语言来实现一个简单的http请求，请求 www.cnblogs.com 首页

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include<stdio.h>

include<stdlib.h>

include<string.h> //strlen

include<sys/socket.h>

include<arpa/inet.h> //inet_addr

include<netdb.h>

include<errno.h>

int main(int argc, char *argv[])
{
int socket_desc;
struct sockaddr_in server;
char *message;

//Create socket
socket_desc = socket(AF_INET, SOCK_STREAM , 0);
if (socket_desc == -1) {
    printf("Could not create socket");
}

char ip[20] = {0};
char *hostname = "www.cnblogs.com";
struct hostent *hp;
if ((hp = gethostbyname(hostname)) == NULL) {
    return 1;
}

strcpy(ip, inet_ntoa(*(struct in_addr *)hp->h_addr_list[0]));

server.sin_addr.s_addr = inet_addr(ip);
server.sin_family = AF_INET;
server.sin_port = htons(80);


//Connect to remote server
if (connect(socket_desc, (struct sockaddr *)&server, sizeof(server)) < 0) {
    printf("connect error： %s", errno);
    return 1;
}

puts("Connected\n");

//Send some data
//http 协议
message = "GET / HTTP/1.1\r\nHost: www.cnblogs.com\r\n\r\n";

//向服务器发送数据
if (send(socket_desc, message, strlen(message) , 0) < 0) {
    puts("Send failed");
    return 1;
}
puts("Data Send\n");

struct timeval timeout = {3, 0};
setsockopt(socket_desc, SOL_SOCKET, SO_RCVTIMEO, (char *)&timeout, sizeof(struct timeval));

//Receive a reply from the server
//loop
int size_recv, total_size = 0;
char chunk[512];
while(1) {
    memset(chunk , 0 , 512); //clear the variable
    //获取数据
    if ((size_recv =  recv(socket_desc, chunk, 512, 0) ) == -1) {
        if (errno == EWOULDBLOCK || errno == EAGAIN) {
            printf("recv timeout ...\n");
            break;
        } else if (errno == EINTR) {
            printf("interrupt by signal...\n");
            continue;
        } else if (errno == ENOENT) {
            printf("recv RST segement...\n");
            break;
        } else {
            printf("unknown error: %d\n", errno);
            exit(1);
        }
    } else if (size_recv == 0) {
        printf("peer closed ...\n");
        break;
    } else {
        total_size += size_recv;
        printf("%s" , chunk);
    }
}

printf("Reply received, total_size = %d bytes\n", total_size);
return 0;

}
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