wget curl c查看web服务器信息

  来源于CU的一个帖子,问如何查看web服务器信息,忽然想起自己好像也比较想知道,遂google之

[root@dbrg-2 ~]# curl -I www.baidu.com
HTTP/1.1 200 OK
Date: Wed, 29 Jul 2009 02:51:19 GMT
Server: BWS/1.0
Content-Length: 3509
Content-Type: text/html
Cache-Control: private
Expires: Wed, 29 Jul 2009 02:51:19 GMT
Set-Cookie: BAIDUID=0D5F54C0853B7C38D6BD3A3E5EA63C44:FG=1; expires=Wed, 29-Jul-39 02:51:19 GMT; path=/; domain=.baidu.com
P3P: CP=" OTI DSP COR IVA OUR IND COM "

[root@dbrg-2 ~]# wget -S --spider www.baidu.com
--10:51:34-- http://

           => `index.html

 

那么工具是实现了,如何用c来实现呢... 其实也很简单,我刚开始还走了点弯路想的是去查看wget or curl的源码,奈何那种代码相互之间依赖性太强实在不易阅读,于是自己用wireshark抓包, so easy!!!!有兴趣的自己去抓下

 

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>

#define HTTPPORT 80


char* head =
     "HEAD / HTTP/1.0\r\n"
     "Accept: */*\r\n"
     "User-Agent: Wget/1.10.2 (Red Hat modified)\r\n"
     "Host:127.0.0.1\r\n"
     "Connection: Keep-Alive\r\n\r\n";

int connect_URL(char *domain,int port)
{
    int sock;
    struct hostent * host;
    struct sockaddr_in server;
    host = gethostbyname(domain);
    if (host == NULL)
     {
      printf("gethostbyname error\n");
      return -2;
     }

    sock = socket(AF_INET,SOCK_STREAM,0);
    if (sock < 0)
    {
      printf("invalid socket\n");
      return -1;
    }
    memset(&server,0,sizeof(struct sockaddr_in));
    memcpy(&server.sin_addr,host->h_addr_list[0],host->h_length);
    server.sin_family = AF_INET;
    server.sin_port = htons(port);
    return (connect(sock,(struct sockaddr *)&server,sizeof(struct sockaddr)) <0) ? -1 : sock;
}


int main()
{
  int sock;
  int ret;
  char buf[100];
  char *domain = "127.0.0.1";

  
  FILE* fp = fopen("test","w+");
  if(NULL == fp){
    printf("can't open stockcode file!\n");
    return -1;
  }
  

    sock = connect_URL(domain,HTTPPORT);
    if (sock <0){
       printf("connetc err\n");
       return -1;
        }

    send(sock,head,strlen(head),0);

    while(1)
    {
      if((ret=recv(sock,buf,100-1,0))<1)
        break;
      buf[ret]='\0';
      printf("%s", buf);
      fprintf(fp,"%s",buf); //save http data

      }
    
    fclose(fp);
    close(sock);
  
  //printf("bye!\n");

  return 0;
}