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

#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 , );
    if (socket_desc == -) {
        printf("Could not create socket");
    }

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

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

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

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

    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) , ) < ) {
        puts("Send failed");
        return ;
    }
    puts("Data Send\n");

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

    //Receive a reply from the server
    //loop
    int size_recv, total_size = ;
    char chunk[];
    while() {
        memset(chunk ,  , ); //clear the variable
        //获取数据
        if ((size_recv =  recv(socket_desc, chunk, , ) ) == -) {
            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();
            }
        } else if (size_recv == ) {
            printf("peer closed ...\n");
            break;
        } else {
            total_size += size_recv;
            printf("%s" , chunk);
        }
    }

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

编译：

gcc http.c -o http

运行：

./http

就可以看到返回结果了