Youtube使用正则表达式下载php [英] Youtube Video download in php using regex

问题描述

我使用以下代码下载YouTube视频。

 <？php 
 header控制：no-cache，must-revalidate）; // HTTP / 1.1 
 header（Expires：Sat，26 Jul 1997 05:00:00 GMT）; //过去的日期
 
 require_once（'lib / youtube.lib.php'）; 
 
 
 
 if（preg_match（'/ youtube\.com / i'，$ _ GET ['url']））{
 
 if （！preg_match（'/ www\。/ i'，$ _ GET ['url']））{
 $ _GET ['url'] = str_replace（'http：//'，'http：// www。'，$ _ GET ['url']）; 
} 
 list（$ video_id，$ download_link）= get_youtube（$ _ GET ['url']）;} 
 
 else {
 die（'< span style =color：red;>抱歉，无法识别网址...< / span>'）; 
} 
 
？> 
 
 
< p> 
< img src =http://img.youtube.com/vi/<?php echo trim（$ video_id）;？> /1.jpgalt =Preview 1class = ythumb/> 
< img src =http://img.youtube.com/vi/<?php echo trim（$ video_id）;？> /2.jpgalt =Preview 2class = ythumb/> 
< img src =http://img.youtube.com/vi/<?php echo trim（$ video_id）;？> /3.jpgalt =Preview 3class = ythumb/> 
< / p> 
< p> 
< a href =<？php echo trim（$ download_link）;？> class =ydltitle =Download as FLV>下载FLV< / a> 
< a href =<？php echo trim（$ download_link）;？>& fmt = 35class =ydltitle =Download as MP4>下载MP4< / a& 
< a href =<？php echo trim（$ download_link）;？>& fmt = 17class =ydltitle =Download as 3GP>下载3GP< / a& 
< / p> 
  

，我的ge_youtube函数包含在youtube.lib.php文件中。该文件包含代码..

 <？php 
 
 
 
 function get_content_of_url（$ url）{
 $ ohyeah = curl_init（）; 
 curl_setopt（$ ohyeah，CURLOPT_RETURNTRANSFER，1）; 
 curl_setopt（$ ohyeah，CURLOPT_URL，$ url）; 
 $ data = curl_exec（$ ohyeah）; 
 curl_close（$ ohyeah）; 
 // print_r（$ data）; 
 return $ data; 
} 
 
 
 function get_flv_link（$ string）{
 if（preg_match（'/ watch_fullscreen（。*）plid / i'，$ string，$ out） ）{
 
 
 if（！preg_match（'/ watch_fullscreen（。*）plid / i'，$ data，$ out））{
 $ outdata = $ out [1 ]; 
 echo'1'。'< br>'; 
 $ arrs =（explode（'&'，$ outdata））; 
 foreach（$ arrs as $ arr）{
 list（$ i，$ x）= explode（=，$ arr）; 
 $$ i = $ x; 
} 
 $ link ='http://www.youtube.com/get_video?video_id='.$video_id.'&t='.$t; 
 echo'2'; 
 echo $ link; 
 array（$ video_id，$ link）; 
 return array（$ video_id，$ link）; 
} 
} 
} 
 
 function get_youtube（$ url）{
 
 $ stream = get_content_of_url（$ url）; 
 return get_flv_link（$ stream）; 
} 
 
 
 
？> 
  

输出对我来说非常有趣。在输出中不显示错误。但仍然可以得到的东西。

 > < a href =<？php echo trim（$ download_link）;？>& fmt = 17class =ydl
> title =Download as 3GP>下载3GP< / a> 
  

显示在结果中，但链接指向localhost。

似乎我缺少一些技巧。让我告诉你，我发现这个脚本，同时试图学习php和curl ..
任何suggesstion或帮助从你？

感谢

解决方案

问题不是正则表达式，问题是图书馆制作的YouTube页面格式的假设。替换：

 } 
 
 function get_youtube（$ url）{
  
 
 
 
与
  else {echo无匹配; } 
} 
 
 function get_youtube（$ url）{
  
 （在 get_flv_link（）添加 else  >），您会收到一条消息，指出内容不匹配。这可能意味着YouTube改变了他们的页面格式（可能是因为人们试图像这样刮）。
 
 
 
此外，我很困惑：
  if（preg_match（'/ watch_fullscreen（。*）plid / i'，$ string，$ out））{
 if ！preg_match（'/ watch_fullscreen（。*）plid / i'，$ data，$ out））{
  
那就说如果匹配，那么检查它是否不匹配一个不同的变量（这里没有声明）。即使页面内容与预期内容相匹配，那么您可能还需要在库中修复的其他位。
 
i am using following code for downloading youtube video.
    <?php
header("Cache-Control: no-cache, must-revalidate"); // HTTP/1.1
header("Expires: Sat, 26 Jul 1997 05:00:00 GMT"); // Date in the past

require_once('lib/youtube.lib.php');



if(preg_match('/youtube\.com/i',$_GET['url'])){

    if(!preg_match('/www\./i',$_GET['url'])){
        $_GET['url'] = str_replace('http://','http://www.',$_GET['url']);
    }
    list($video_id,$download_link) = get_youtube($_GET['url']);}

else{
    die('<span style="color:red;">Sorry, the URL is not recognized..</span>');
}

    ?>


    <p>
    <img src="http://img.youtube.com/vi/<?php echo trim($video_id);?>/1.jpg" alt="Preview 1" class="ythumb" />
    <img src="http://img.youtube.com/vi/<?php echo trim($video_id);?>/2.jpg" alt="Preview 2" class="ythumb" />
    <img src="http://img.youtube.com/vi/<?php echo trim($video_id);?>/3.jpg" alt="Preview 3" class="ythumb" />
    </p>
    <p>
    <a href="<?php echo trim($download_link);?>" class="ydl" title="Download as FLV">Download FLV</a>
    <a href="<?php echo trim($download_link);?>&fmt=35" class="ydl" title="Download as MP4">Download MP4</a>
    <a href="<?php echo trim($download_link);?>&fmt=17" class="ydl" title="Download as 3GP">Download 3GP</a>
    </p>
and my ge_youtube function is included in youtube.lib.php file. the file contains code..
     <?php



function get_content_of_url($url){
    $ohyeah = curl_init();
    curl_setopt($ohyeah, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ohyeah, CURLOPT_URL, $url);
    $data = curl_exec($ohyeah);
    curl_close($ohyeah);
    //print_r($data);
    return $data;
}


function get_flv_link($string) {  
if (preg_match('/watch_fullscreen(.*)plid/i', $string, $out)){


    if (!preg_match('/watch_fullscreen(.*)plid/i', $data, $out)) {  
    $outdata = $out[1];
      echo '1'.'<br>';
    $arrs = (explode('&',$outdata));
    foreach($arrs as $arr){
        list($i,$x) = explode("=",$arr);
        $$i = $x;
    }
    $link = 'http://www.youtube.com/get_video?video_id='.$video_id.'&t='.$t;
    echo '2';
    echo $link;
array($video_id,$link);
    return array($video_id,$link);
} 
}
}

function get_youtube($url){

    $stream = get_content_of_url($url);
 return get_flv_link($stream);
}



?>
the output is very interesting for me. there is no error displayed in output. but still i can get notthing. in code  
> <a href="<?php echo trim($download_link);?>&fmt=17" class="ydl"
> title="Download as 3GP">Download 3GP</a>
is displayed in result but the link points to localhost. 

It seems that i am missing some trick. Let me tell you i found this script while trying to learn php and curl ..
any suggesstion or help from you?? Would you please help me convert this code to a working code?

thanks
解决方案
The problem isn't the regex, the problem is the assumptions of YouTube's page format that the library makes. Replace:
}

function get_youtube($url){
with
    else { echo "No match"; }
}

function get_youtube($url){
(which adds an else to the if in get_flv_link()) and you'll get a message saying that the content doesn't match. This probably means that YouTube have altered their page format (possibly because people were trying to scrape it like this).

Also, I'm confused by:
if (preg_match('/watch_fullscreen(.*)plid/i', $string, $out)){
    if (!preg_match('/watch_fullscreen(.*)plid/i', $data, $out)) {
That says "if it matches then check if it doesn't match on a different variable (which hasn't been declared at this point)". Even if the page content matched the expected content then you'd probably have other bits that needed fixing in the library.

                        
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