发布一个用PHP fsockopen写的HTTP下载的类

2007-02-22 00:00:00 作者：

如果支持打开远程内容的选项的话，实际上php用fopen或file_get_contents都能获得一个网页的内容，但是默认的函数有个不足的地方就是无法获取HTTP头，这在一些特殊的应用中很不方便，如，有一个链接：

http://www.abc.com/showvd.asp?id=18

假如它返回的是一个图片，用默认函数就很难识别，但如果通过HTTP应答头来判断就简单多了，此外如果对方通过 Refer 来防盗链的话，也是无法获取的，用HTTP类就能完美解决这些问题，而且速度也相差无几。

使用方法：

$hd = new DedeHttpDown();
$hd->OpenUrl("http://www.dedecms.com");
echo $hd->GetHtml();
//如果保存为文件则用 $hd->SaveBin("dede.html");
$hd->Close();

获得http请求头用
$hd->GetHead("key")
设置请求头
$hd->SetHead(key,value); (必须在调用 OpenUrl 之前设定)

代码如下:

<?
/* ---------------------------------------------------------------------
//织梦Http下载类V1.0
//出自：织梦之旅 http://www.dedecms.com
//作者: IT柏拉图
//时间: 2005-11-13 12:39
//声明: 首发在落伍者网站，转载请保留版权信息
--------------------------------------------------------------------- */
class DedeHttpDown
{
 var $m_url = "";
 var $m_urlpath = "";
 var $m_scheme = "http";
 var $m_host = "";
 var $m_port = "80";
 var $m_user = "";
 var $m_pass = "";
 var $m_path = "/";
 var $m_query = "";
 var $m_fp = "";
 var $m_error = "";
 var $m_httphead = "" ;
 var $m_html = "";
 var $m_puthead = "";
 var $BaseUrlPath = "";
 var $HomeUrl = "";
 var $JumpCount = 0;//防止多重重定向陷入死循环
 //
 //初始化系统
 //
 function PrivateInit($url)
 {
 if($url=="") return ;
 $urls = "";
 $urls = @parse_url($url);
 $this->m_url = $url;
 if(is_array($urls))
 {
 $this->m_host = $urls["host"];
 if(!empty($urls["scheme"])) $this->m_scheme = $urls["scheme"];

 if(!empty($urls["user"])){
 $this->m_user = $urls["user"];
 }

 if(!empty($urls["pass"])){
 $this->m_pass = $urls["pass"];
 }

 if(!empty($urls["port"])){
 $this->m_port = $urls["port"];
 }

 if(!empty($urls["path"])) $this->m_path = $urls["path"];
 $this->m_urlpath = $this->m_path;

 if(!empty($urls["query"])){
 $this->m_query = $urls["query"];
 $this->m_urlpath .= "?".$this->m_query;
 }
 $this->HomeUrl = $urls["host"];
 $this->BaseUrlPath = $this->HomeUrl.$urls["path"];
 $this->BaseUrlPath = ereg_replace("/([^/]*)\.(.*)$","/",$this->BaseUrlPath);
 $this->BaseUrlPath = ereg_replace("/$","",$this->BaseUrlPath);
 }
 }
 //
 //打开指定网址
 //
 function OpenUrl($url)
 {
 //重设各参数
 $this->m_url = "";
 $this->m_urlpath = "";
 $this->m_scheme = "http";
 $this->m_host = "";
 $this->m_port = "80";
 $this->m_user = "";
 $this->m_pass = "";
 $this->m_path = "/";
 $this->m_query = "";
 $this->m_error = "";
 $this->JumpCount = 0;
 $this->m_httphead = Array() ;
 //$this->m_puthead = "";
 $this->m_html = "";
 $this->Close();
 //初始化系统
 $this->PrivateInit($url);
 $this->PrivateStartSession();
 }
 //
 //打开303重定向网址
 //
 function JumpOpenUrl($url)
 {
 //重设各参数
 $this->m_url = "";
 $this->m_urlpath = "";
 $this->m_scheme = "http";
 $this->m_host = "";
 $this->m_port = "80";
 $this->m_user = "";
 $this->m_pass = "";
 $this->m_path = "/";
 $this->m_query = "";
 $this->m_error = "";
 $this->JumpCount++;
 $this->m_httphead = Array() ;
 $this->m_html = "";
 $this->Close();
 //初始化系统
 $this->PrivateInit($url);
 $this->PrivateStartSession();
 }
 //
 //获得某操作错误的原因
 //
 function printError()
 {
 echo "错误信息：".$this->m_error;
 echo "具体返回头： ";
 foreach($this->m_httphead as $k=>$v)
 { echo "$k => $v \r\n"; }
 }
 //
 //判别用Get方法发送的头的应答结果是否正确
 //
 function IsGetOK()
 {
 if( ereg("^2",$this->GetHead("http-state")) )
 { return true; }
 else
 {
 $this->m_error .= $this->GetHead("http-state")." - ".$this->GetHead("http-describe")." ";
 return false;
 }
 }
 //
 //看看返回的网页是否是text类型
 //
 function IsText()
 {
 if(ereg("^2",$this->GetHead("http-state"))
 && eregi("^text",$this->GetHead("content-type")))
 { return true; }
 else
 {
 $this->m_error .= "内容为非文本类型或网址重定向 ";
 return false;
 }
 }
 //
 //判断返回的网页是否是特定的类型
 //
 function IsContentType($ctype)
 {
 if(ereg("^2",$this->GetHead("http-state"))
 && $this->GetHead("content-type")==strtolower($ctype))
 { return true; }
 else
 {
 $this->m_error .= "类型不对 ".$this->GetHead("content-type")." ";
 return false;
 }
 }
 //
 //用Http协议下载文件
 //
 function SaveToBin($savefilename)
 {
 if(!$this->IsGetOK()) return false;
 if(@feof($this->m_fp)) { $this->m_error = "连接已经关闭！"; return false; }
 $fp = fopen($savefilename,"w");
 while(!feof($this->m_fp)){
 fwrite($fp,fread($this->m_fp,1024));
 }
 fclose($this->m_fp);

 fclose($fp);
 return true;
 }
 //
 //保存网页内容为Text文件
 //
 function SaveToText($savefilename)
 {
 if($this->IsText()) $this->SaveBinFile($savefilename);
 else return "";
 }
 //
 //用Http协议获得一个网页的内容
 //
 function GetHtml()
 {
 if(!$this->IsText()) return "";
 if($this->m_html!="") return $this->m_html;
 if(!$this->m_fp||@feof($this->m_fp)) return "";
 while(!feof($this->m_fp)){
 $this->m_html .= fgets($this->m_fp,256);
 }
 @fclose($this->m_fp);
 return $this->m_html;
 }
 //
 //开始HTTP会话
 //
 function PrivateStartSession()
 {

 if(!$this->PrivateOpenHost()){
 $this->m_error .= "打开远程主机出错!";
 return false;
 }

 if($this->GetHead("http-edition")=="HTTP/1.1") $httpv = "HTTP/1.1";
 else $httpv = "HTTP/1.0";

 //发送固定的起始请求头GET、Host信息
 fputs($this->m_fp,"GET ".$this->m_urlpath." $httpv\r\n");
 $this->m_puthead["Host"] = $this->m_host;

 //发送用户自定义的请求头
 if(!isset($this->m_puthead["Accept"])) { $this->m_puthead["Accept"] = "*/*"; }
 if(!isset($this->m_puthead["User-Agent"])) { $this->m_puthead["User-Agent"] = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2)"; }
 if(!isset($this->m_puthead["Refer"])) { $this->m_puthead["Refer"] = "http://".$this->m_puthead["Host"]; }
 foreach($this->m_puthead as $k=>$v){
 $k = trim($k);
 $v = trim($v);
 if($k!=""&&$v!=""){
 fputs($this->m_fp,"$k: $v\r\n");
 }
 }

 //发送固定的结束请求头
 //HTTP1.1协议必须指定文档结束后关闭链接,否则读取文档时无法使用feof判断结束
 if($httpv=="HTTP/1.1") fputs($this->m_fp,"Connection: Close\r\n\r\n");
 else fputs($this->m_fp,"\r\n");

 //获取应答头状态信息
 $httpstas = explode(" ",fgets($this->m_fp,256));
 $this->m_httphead["http-edition"] = trim($httpstas[0]);
 $this->m_httphead["http-state"] = trim($httpstas[1]);
 $this->m_httphead["http-describe"] = "";
 for($i=2;$i<count($httpstas);$i++){
 $this->m_httphead["http-describe"] .= " ".trim($httpstas[$i]);
 }
 //获取详细应答头
 while(!feof($this->m_fp)){
 $line = trim(fgets($this->m_fp,256));
 if($line == "") break;
 $hkey = "";
 $hvalue = "";
 $v = 0;
 for($i=0;$i<strlen($line);$i++){
 if($v==1) $hvalue .= $line[$i];
 if($line[$i]==":") $v = 1;
 if($v==0) $hkey .= $line[$i];
 }
 $hkey = trim($hkey);
 if($hkey!="") $this->m_httphead[strtolower($hkey)] = trim($hvalue);
 }
 //判断是否是3xx开头的应答
 if(ereg("^3",$this->m_httphead["http-state"]))
 {
 if($this->JumpCount > 3) return;
 if(isset($this->m_httphead["location"])){
 $newurl = $this->m_httphead["location"];
 if(eregi("^http",$newurl)){
 $this->JumpOpenUrl($newurl);
 }
 else{
 $newurl = $this->FillUrl($newurl);
 $this->JumpOpenUrl($newurl);
 }
 }
 else
 { $this->m_error = "无法识别的转移应答！"; }
 }//
 }
 //
 //获得一个Http头的值
 //
 function GetHead($headname)
 {
 $headname = strtolower($headname);
 if(isset($this->m_httphead[$headname]))
 return $this->m_httphead[$headname];
 else
 return "";
 }
 //
 //设置Http头的值
 //
 function SetHead($skey,$svalue)
 {
 $this->m_puthead[$skey] = $svalue;
 }
 //
 //打开连接
 //
 function PrivateOpenHost()
 {
 if($this->m_host=="") return false;
 $this->m_fp = @fsockopen($this->m_host, $this->m_port, &$errno, &$errstr,10);
 if(!$this->m_fp){
 $this->m_error = $errstr;
 return false;
 }
 else{
 return true;
 }
 }
 //
 //关闭连接
 //
 function Close(){
 @fclose($this->m_fp);
 }
 //
 //补全相对网址
 //
 function FillUrl($surl)
 {
 $i = 0;
 $dstr = "";
 $pstr = "";
 $okurl = "";
 $pathStep = 0;
 $surl = trim($surl);
 if($surl=="") return "";
 $pos = strpos($surl,"#");
 if($pos>0) $surl = substr($surl,0,$pos);
 if($surl[0]=="/"){
 $okurl = "http://".$this->HomeUrl."/".$surl;
 }
 else if($surl[0]==".")
 {
 if(strlen($surl)<=2) return "";
 else if($surl[0]=="/")
 {
 $okurl = "http://".$this->BaseUrlPath."/".substr($surl,2,strlen($surl)-2);
 }
 else{
 $urls = explode("/",$surl);
 foreach($urls as $u){
 if($u=="..") $pathStep++;
 else if($i<count($urls)-1) $dstr .= $urls[$i]."/";
 else $dstr .= $urls[$i];
 $i++;
 }
 $urls = explode("/",$this->BaseUrlPath);
 if(count($urls) <= $pathStep)
 return "";
 else{
 $pstr = "http://";
 for($i=0;$i<count($urls)-$pathStep;$i++)
 { $pstr .= $urls[$i]."/"; }
 $okurl = $pstr.$dstr;
 }
 }
 }
 else
 {
 if(strlen($surl)<7)
 $okurl = "http://".$this->BaseUrlPath."/".$surl;
 else if(strtolower(substr($surl,0,7))=="http://")
 $okurl = $surl;
 else
 $okurl = "http://".$this->BaseUrlPath."/".$surl;
 }
 $okurl = eregi_replace("^(http://)","",$okurl);
 $okurl = eregi_replace("/{1,}","/",$okurl);
 return "http://".$okurl;
 }
}
?>

发布一个用PHP fsockopen写的HTTP下载的类

您可能感兴趣的文章: