<td valign="top"> <font face='宋體' size='2'> void endprotoent(void);<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 函數(shù)說明 </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> endprotoent()用來關(guān)閉由getprotoent()打開的文件。<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 返回值 </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> <br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 范例 </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> 參考getprotoent()<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top">　 
      <div align="right"><br>
        <font face='宋體' size='2'><a name=linuxc267></a></font> </div>
    </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> <br>
        </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> <br>
      endservent（結(jié)束網(wǎng)絡(luò)服務(wù)數(shù)據(jù)的讀取） </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 相關(guān)函數(shù) </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> getservent，getservbyname，getservbyport，setservent<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 表頭文件 </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> #include&lt;netdb.h&gt;<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 定義函數(shù) </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> void endservent(void);<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 函數(shù)說明 </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> endservent()用來關(guān)閉由getservent()所打開的文件。<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 返回值 </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> <br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 范例 </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> 參考getservent()。<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top">　 
      <div align="right"><br>
        <font face='宋體' size='2'><a name=linuxc268></a></font> </div>
    </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> <br>
        </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> <br>
      getsockopt（取得socket狀態(tài)） </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 相關(guān)函數(shù) </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> setsockopt<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 表頭文件 </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> #include&lt;sys/types.h&gt;<br>
      #include&lt;sys/socket.h&gt;<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 定義函數(shù) </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> int getsockopt(int s,int level,int 
      optname,void* optval,socklen_t* optlen);<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 函數(shù)說明 </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> getsockopt()會將參數(shù)s所指定的socket狀態(tài)返回。參數(shù)optname代表欲取得何種選項狀態(tài)，而參數(shù)optval則指向欲保存結(jié)果的內(nèi)存地址，參數(shù)optlen則為該空間的大小。參數(shù)level、optname請參考setsockopt()。<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 返回值 </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> 成功則返回0，若有錯誤則返回-1，錯誤原因存于errno<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 錯誤代碼 </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> EBADF 參數(shù)s 并非合法的socket處理代碼<br>
      ENOTSOCK 參數(shù)s為一文件描述詞，非socket<br>
      ENOPROTOOPT 參數(shù)optname指定的選項不正確<br>
      EFAULT 參數(shù)optval指針指向無法存取的內(nèi)存空間<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 范例 </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> #include&lt;sys/types.h&gt;<br>
      #include&lt;sys/socket.h&gt;<br>
      main()<br>
      {<br>
      int s,optval,optlen = sizeof(int);<br>
      if((s = socket(AF_INET,SOCK_STREAM,0))&lt;0) perror(“socket”);<br>
      getsockopt(s,SOL_SOCKET,SO_TYPE,&optval,&optlen);<br>
      printf(“optval = %d\n”,optval);<br>
      close(s);}<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 執(zhí)行 </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> optval = 1 /*SOCK_STREAM的定義正是此值*/<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top">　 
      <div align="right"><br>
        <font face='宋體' size='2'><a name=linuxc269></a></font> </div>
    </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> <br>
        </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> <br>
      htonl（將32位主機(jī)字符順序轉(zhuǎn)換成網(wǎng)絡(luò)字符順序） </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 相關(guān)函數(shù) </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> htons，ntohl，ntohs<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 表頭文件 </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> #include&lt;netinet/in.h&gt;<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 定義函數(shù) </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> unsigned long int htonl(unsigned 
      long int hostlong);<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 函數(shù)說明 </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> htonl（）用來將參數(shù)指定的32位hostlong 轉(zhuǎn)換成網(wǎng)絡(luò)字符順序。<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 返回值 </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> 返回對應(yīng)的網(wǎng)絡(luò)字符順序。<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 范例 </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> 參考getservbyport()或connect()。<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top">　 
      <div align="right"><br>
        <font face='宋體' size='2'><a name=linuxc270></a></font> </div>
    </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> <br>
        </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> <br>
      htons（將16位主機(jī)字符順序轉(zhuǎn)換成網(wǎng)絡(luò)字符順序） </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 相關(guān)函數(shù) </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> htonl，ntohl，ntohs<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 表頭文件 </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> #include&lt;netinet/in.h&gt;<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 定義函數(shù) </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> unsigned short int htons(unsigned 
      short int hostshort);<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 函數(shù)說明 </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> htons()用來將參數(shù)指定的16位hostshort轉(zhuǎn)換成網(wǎng)絡(luò)字符順序。<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 返回值 </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> 返回對應(yīng)的網(wǎng)絡(luò)字符順序。<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 范例 </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> 參考connect()。<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top">　 
      <div align="right"><br>
        <font face='宋體' size='2'><a name=linuxc271></a></font> </div>
    </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> <br>
        </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> <br>
      inet_addr（將網(wǎng)絡(luò)地址轉(zhuǎn)成二進(jìn)制的數(shù)字） </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 相關(guān)函數(shù) </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> inet_aton，inet_ntoa<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 表頭文件 </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> #include&lt;sys/socket.h&gt;<br>
      #include&lt;netinet/in.h&gt;<br>
      #include&lt;arpa/inet.h&gt;<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 定義函數(shù) </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> unsigned long int inet_addr(const 
      char *cp);<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 函數(shù)說明 </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> inet_addr()用來將參數(shù)cp所指的網(wǎng)絡(luò)地址字符串轉(zhuǎn)換成網(wǎng)絡(luò)所使用的二進(jìn)制數(shù)字。網(wǎng)絡(luò)地址字符串是以數(shù)字和點組成的字符串，例如:“163.13.132.68”。<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top"> 
      <div align="right"><font face='宋體' size='2'> 返回值 </font> </div>
    </td>
    <td valign="top"> <font face='宋體' size='2'> 成功則返回對應(yīng)的網(wǎng)絡(luò)二進(jìn)制的數(shù)字，失敗返回-1。<br>
      </font> </td>
  </tr>
  <tr> 
    <td width="80" valign="top">　 
      <div align="right"><br>
        <font face='宋體' size='2'><a name=linuxc272></a></font> </div>
    </td>
  </tr>
  <tr>