php简单实现spider 抓URL

<?php
//2015-4-16 @developd
//获取网页中的URL 保存URL.txt中
//用法 php spider.php url
if($argc !== 2){
   echo "No Target...\r\n";
   echo "Usage:php spider.php url \r\n";
   echo "eg:php spider.php www.baidu.com \r\n";
   exit();        
}else{
    $url = $argv[‘1‘];
}
if(empty($url)){
    echo "URL Error \r\n";
    exit();    
}
$filename ="$url";
$url = "http://".$url;
if(!file_exists($filename)){
        $file=fopen($filename,"a+");
        fclose($file);
}
$site=substr($url,0,strpos($url,‘/‘,8));
$base=substr($url,0,strpos($url,‘/‘)+1);
$fp=fopen($url,‘r‘);
while(!feof($fp)){
        $contents.= fread($fp,1024);
        //var_dump($content);
}
$pattern = "|href=[‘\"]?([^‘\"]+)[‘\"]|U";
preg_match_all($pattern,$contents,$regArr,PREG_SET_ORDER);

for($i=0;$i<count($regArr);$i++){
    if(substr($regArr[$i][1],0,1)=="/")
            $data ="URL".($i+1).":".$site.$regArr[$i][1].PHP_EOL;
    else
            $data = "URL".($i+1).":".$regArr[$i][1].PHP_EOL;
    $res = file_put_contents($filename,$data,FILE_APPEND);
}
if(empty($res)){
    echo "No URLS...\r\n";
}else{
    echo "Get URLS success...\r\n";
}
fclose($fp);
?>