C：在linux中发送http get请求

Question

我试图在端口80上建立一个连接localhost并发送一个简单的http get请求，同时运行wireshark并查看报头。下面是我的代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h> 
#include <sys/socket.h>
#include <pthread.h>
#include <netinet/in.h>
#include <errno.h>
#include <string.h>


int main(int argc, char *argv[])
{

  int yes = 1;
 char buffer[1024];
 int newsockfd, portno, recv_length, sockfd;
 socklen_t clilen;
 struct sockaddr_in serv_addr, cli_addr;
 ssize_t number;
 if (sockfd < 0) 
    error("ERROR opening socket");
 bzero((char *) &serv_addr, sizeof(serv_addr));


  sockfd = socket(AF_INET, SOCK_STREAM, 0);

 serv_addr.sin_family = AF_INET;
 serv_addr.sin_addr.s_addr = 0;
 serv_addr.sin_port = htons(80);




 connect(sockfd,(struct sockaddr *) &serv_addr,sizeof(serv_addr));


 if(send(sockfd, 


 "GET / HTTP/1.1\r\n
 Host: localhost\r\n
 Connection: Keep-alive\r\n
 Cache-Control: max-age=0\r\n
 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,;q=0.8\r\n
 User-Agent: Mozilla/5.0 (X11; Linux i686) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/40.0.2214.91 Safari/537.36\r\n
 Accept-Encoding: gzip, deflate, sdch\r\n
 Accept-Language: en-US,en;q=0.8\r\n\r\n", 

 strlen("GET / HTTP/1.1\r\n
 Host: localhost\r\n
 Connection: Keep-alive\r\n
 Cache-Control: max-age=0\r\n
 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,;q=0.8\r\n
 User-Agent: Mozilla/5.0 (X11; Linux i686) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/40.0.2214.91 Safari/537.36\r\n
 Accept-Encoding: gzip, deflate, sdch\r\n
 Accept-Language: en-US,en;q=0.8\r\n\r\n"),

 0) > 0)

 {
    printf("GET send from %d\n", sockfd);
 }
 else
 {
    printf("Problem in send %s\n", strerror(errno));
 }

但当我编译并运行它时，它会给我带来很多错误。这是Errros的图像。发生此错误后，我将send函数更改为这个
send（sockfd,“get/http/1.1\r\n host:localhost\r\n\r\n”，strlen（“get/http/1.1\r\n host:localhost\r\n\r\n”）
编译进行得很好，但wireshark显示给我HTTP/1.0 400错误请求(text/html)，所以我没有什么问题。
1)我使用过的send函数之间有什么区别？我的意思是，如果我发送
GET/HTTP/1.1\r\n主机:localhost\r\n\r\n
或
GET/HTTP/1.1\r\n主机:localhost\r\n连接：keep-alive\r\n cache-control:max-age=0\r\n accept:text/html,application/xhtml+xml,application/xml；q=0.9,image/webp；q=0.8\r\n用户代理:mozilla/5.0(x11；Linux i686)appleWebkit/537.36（KHTML,like Gecko)chrome/40.0.2214.91 safari/537.36\r\n accept-encoding真的有关系吗：gzip,deflate,sdch\r\n accept-language：en-US,en；q=0.8\r\n\r\n
2)如何配置发送函数以发出正确的HTTP GET请求？
希望您能帮助。谢谢。

Answer 1

字符串中有文字换行符！您需要关闭并重新打开每一行的报价。例如：

if(send(sockfd, 
 "GET / HTTP/1.1\r\n"
 "Host: localhost\r\n"
 "Connection: Keep-alive\r\n"
 "Cache-Control: max-age=0\r\n"
 ...