http命令请求练习（test_for_http_request）

 

 

写了一个小程序，练练网络编程，一是为了之后要实现的一个搜索引擎，二是为了明天的trend面试和晚上的盛大笔试。God bless me！

 

代码

   
     

    
      
    
       1 
    
      #include
    
      <
    
      sys
    
      /
    
      types.h
    
      >
    
      

    
       2 
    
      #include
    
      <
    
      unistd.h
    
      >
    
      

    
       3 
    
      #include
    
      <
    
      sys
    
      /
    
      socket.h
    
      >
    
      

    
       4 
    
      #include
    
      <
    
      arpa
    
      /
    
      inet.h
    
      >
    
      

    
       5 
    
      #include
    
      <
    
      netdb.h
    
      >
    
      

    
       6 
    
      

    
       7 
    
      #include
    
      <
    
      stdio.h
    
      >
    
      

    
       8 
    
      #include
    
      <
    
      string
    
      .h
    
      >
    
      

    
       9 
    
      

    
      10 
    
      

    
      11 
    
       
    
      #define
    
       PORT 80
    
      

    
      12 
    
       
    
      #define
    
       URL "www.seu.edu.cn"
    
      

    
      13 
    
      

    
      14 
    
      

    
      15 
    
       
    
      int
    
       main()

    
      16 
    
      {

    
      17 
    
       
    
      int
    
       fd 
    
      =
    
       socket(PF_INET,SOCK_STREAM,
    
      0
    
      );

    
      18 
    
      

    
      19 
    
       
    
      if
    
      (fd 
    
      <
    
       
    
      0
    
      )

    
      20 
    
       {

    
      21 
    
       printf(
    
      "
    
      socket error ! %m
    
      "
    
      );

    
      22 
    
       
    
      return
    
       
    
      -
    
      1
    
      ;

    
      23 
    
       }

    
      24 
    
      

    
      25 
    
       
    
      struct
    
       sockaddr_in addr;

    
      26 
    
       addr.sin_family 
    
      =
    
       AF_INET;

    
      27 
    
       addr.sin_port
    
      =
    
      htons(PORT);

    
      28 
    
       
    
      struct
    
       hostent
    
      *
    
       phost;

    
      29 
    
       in_addr_t ip_addr;

    
      30 
    
       
    
      //
    
      the url is ip address
    
      

    
      31 
    
       
    
       
    
      if
    
      ((ip_addr
    
      =
    
      inet_addr(URL))
    
      !=
    
       INADDR_NONE)

    
      32 
    
       {

    
      33 
    
       addr.sin_addr.s_addr 
    
      =
    
       ip_addr;

    
      34 
    
       }

    
      35 
    
       
    
      else
    
      

    
      36 
    
       {

    
      37 
    
       
    
      //
    
      find the ip address of the url
    
      

    
      38 
    
       phost
    
      =
    
       gethostbyname(URL);

    
      39 
    
       
    
      if
    
      (phost)

    
      40 
    
       {

    
      41 
    
       addr.sin_addr 
    
      =
    
       
    
      *
    
      (
    
      struct
    
       in_addr
    
      *
    
      )(phost
    
      ->
    
      h_addr_list)[
    
      0
    
      ];

    
      42 
    
       
    
      char
    
       addr_ip[INET_ADDRSTRLEN];

    
      43 
    
       printf(
    
      "
    
      the address is %s\n
    
      "
    
      ,inet_ntop(AF_INET,
    
      &
    
      (addr.sin_addr),addr_ip,INET_ADDRSTRLEN));

    
      44 
    
       }

    
      45 
    
       
    
      else
    
      

    
      46 
    
       {

    
      47 
    
       printf(
    
      "
    
      gethostbyname error!\n
    
      "
    
      );

    
      48 
    
       
    
      return
    
       
    
      -
    
      2
    
      ;

    
      49 
    
       }

    
      50 
    
       }

    
      51 
    
      

    
      52 
    
       
    
      if
    
      (connect(fd,(
    
      struct
    
       sockaddr
    
      *
    
      )
    
      &
    
      addr,
    
      sizeof
    
      (addr))
    
      !=
    
      0
    
      )

    
      53 
    
       {

    
      54 
    
       printf(
    
      "
    
      connect error!%m \n 
    
      "
    
      );

    
      55 
    
       
    
      return
    
       
    
      -
    
      3
    
      ;

    
      56 
    
       }

    
      57 
    
       
    
      //
    
      Note that every request option should end with \r\n and we should add an addtional \r\n at th end of request
    
      

    
      58 
    
       
    
      const
    
       
    
      char
    
      *
    
       request 
    
      =
    
       
    
      "
    
      GET / HTTP/1.0\r\n\r\n
    
      "
    
      ;

    
      59 
    
       
    
      int
    
       nwrite 
    
      =
    
       write(fd,request,strlen(request)
    
      +
    
      1
    
      );

    
      60 
    
      

    
      61 
    
       
    
      if
    
      (nwrite
    
      <
    
      0
    
      )

    
      62 
    
       {

    
      63 
    
       printf(
    
      "
    
      write error %m \n
    
      "
    
      );

    
      64 
    
       
    
      return
    
       
    
      -
    
      3
    
      ;

    
      65 
    
       }

    
      66 
    
      

    
      67 
    
       
    
      int
    
       nread;

    
      68 
    
       
    
      char
    
       readbuf[
    
      1024
    
      ];

    
      69 
    
       
    
      while
    
      (nread 
    
      =
    
       read(fd,readbuf,
    
      1024
    
      ))

    
      70 
    
       {

    
      71 
    
       write(STDOUT_FILENO,readbuf,nread);

    
      72 
    
       }

    
      73 
    
       close(fd);

    
      74 
    
       
    
      return
    
       
    
      0
    
      ;

    
      75 
    
      }

    
      76 
   
     

 

注意：request的格式问题，每个命令后加\r\n，最后也要加上额外的\r\n，之前调了好久才发现出不来结果是因为这个...