本文实例为大家分享了php远程下载类，如下

<?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://dldir1.qq.com/qqfile/qq/QQ8.2/17724/QQ8.2.exe"); # 远程文件地址

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

$file->Close(); # 释放资源

以上就是本文的全部内容，希望对大家的学习有所帮助。