PHP download remote file sharing

<?php

/**

 * 下载远程文件类支持断点续传

 */

class HttpDownload {

  private $m_url = "";

  private $m_urlpath = "";

  private $m_scheme = "http";

  private $m_host = "";

  private $m_port = "80";

  private $m_user = "";

  private $m_pass = "";

  private $m_path = "/";

  private $m_query = "";

  private $m_fp = "";

  private $m_error = "";

  private $m_httphead = "" ;

  private $m_html = "";

  /**

   * 初始化

   */

  public function PrivateInit($url){

    $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;

      }

    }

  }

  /**

  * 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->m_httphead = "" ;

    $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

  */

  public function printError() {

    echo "错误信息：".$this->m_error;

    echo "具体返回头：<br>";

    foreach($this->m_httphead as $k=>$v) {

      echo "$k => $v <br>\r\n";

    }

  }

  /**

  * 判别用Get方法发送的头的应答结果是否正确

  */

  public function IsGetOK() {

    if( ereg("^2",$this->GetHead("http-state")) ) {

      return true;

    } else {

      $this->m_error .= $this->GetHead("http-state")." - ".$this->GetHead("http-describe")."<br>";

      return false;

    }

  }

  /**

  * 看看返回的网页是否是text类型

  */

  public 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<br>";

      return false;

    }

  }

  /**

  * 判断返回的网页是否是特定的类型

  */

  public 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")."<br>";

      return false;

    }

  }

  /**

  * 用 HTTP 协议下载文件

  */

  public 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") or die("写入文件 $savefilename 失败！");

    while (!feof($this->m_fp)) {

      @fwrite($fp,fgets($this->m_fp,256));

    }

    @fclose($this->m_fp);

    return true;

  }

  /**

  * 保存网页内容为 Text 文件

  */

  public function SaveToText($savefilename) {

    if ($this->IsText()) {

      $this->SaveBinFile($savefilename);

    } else {

      return "";

    }

  }

  /**

  * 用 HTTP 协议获得一个网页的内容

  */

  public 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

  */

  public 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";

    }

    fputs($this->m_fp,"GET ".$this->m_urlpath." $httpv\r\n");

    fputs($this->m_fp,"Host: ".$this->m_host."\r\n");

    fputs($this->m_fp,"Accept: */*\r\n");

    fputs($this->m_fp,"User-Agent: Mozilla/4.0+(compatible;+MSIE+6.0;+Windows+NT+5.2)\r\n");

    #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");

    }

    $httpstas = fgets($this->m_fp,256);

    $httpstas = split(" ",$httpstas);

    $this->m_httphead["http-edition"] = trim($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]);

    }

    while (!feof($this->m_fp)) {

      $line = str_replace("\"","",trim(fgets($this->m_fp,256)));

      if($line == "") break;

      if (ereg(":",$line)) {

        $lines = split(":",$line);

        $this->m_httphead[strtolower(trim($lines[0]))] = trim($lines[1]);

      }

    }

  }

  /**

  * 获得一个Http头的值

  */

  public function GetHead($headname) {

    $headname = strtolower($headname);

    if (isset($this->m_httphead[$headname])) {

      return $this->m_httphead[$headname];

    } else {

      return "";

    }

  }

  /**

  * 打开连接

  */

  public 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

  */

  public function Close(){

    @fclose($this->m_fp);

  }

}

#两种使用方法，分别如下：

#打开网页

$httpdown = new HttpDownload();

$httpdown->OpenUrl("http://www.google.com.hk");

echo $httpdown->GetHtml();

$httpdown->Close();

#下载文件

$file = new HttpDownload(); # 实例化类

$file->OpenUrl("http://www.ti.com.cn/cn/lit/an/rust020/rust020.pdf"); # 远程文件地址

$file->SaveToBin("rust020.pdf"); # 保存路径及文件名

$file->Close(); # 释放资源

?>