php获取网页内容方法 采集程序

用php采集程序，抓取页面的内容在实际的开发当中是非常有用的，如作一个简单的内容采集器，提取网页中的部分内容等等

抓取到的内容在通过正则表达式做一下过滤就得到了你想要的内容，几种常用的用php抓取网页中的内容的方法。
1.file_get_contents 

<?php
$url = "http://www.songshujin.com";
$contents = file_get_contents($url);
//如果出现中文乱码使用下面代码
//$getcontent = iconv("gb2312", "utf-8",$contents);
echo $contents;
?>

2.curl 

<?php
$url = "http://www.songshujin.com";
$ch = curl_init();
$timeout = 5;
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $timeout);
//在需要用户检测的网页里需要增加下面两行
//curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
//curl_setopt($ch, CURLOPT_USERPWD, US_NAME.":".US_PWD);
$contents = curl_exec($ch);
curl_close($ch);
echo $contents;
?>

3.fopen->fread->fclose 

<?php
$handle = fopen ("http://www.songshujin.com", "rb");
$contents = "";
do {
$data = fread($handle, 1024);
if (strlen($data) == 0) {
break;
}
$contents .= $data;
} while(true);
fclose ($handle);
echo $contents;
?>

注： 
1.使用file_get_contents和fopen必须空间开启allow_url_fopen。方法：编辑php.ini，设置allow_url_fopen = On，allow_url_fopen关闭时fopen和file_get_contents都不能打开远程文件。 
2.使用curl必须空间开启curl。方法：windows下修改php.ini，将extension=php_curl.dll前面的分号去掉，而且需要拷贝ssleay32.dll和libeay32.dll到C:\WINDOWS\system32下；Linux下要安装curl扩展。
自己写的采集程序：

public function foreign(){
header("Content-type:text/html;charset=utf-8");
$content = file_get_contents("http://www.songshujin.com");
$preg="/<tbody[\s|\S]*?<\/tbody>/";
preg_match_all($preg,$content,$arr);
$content=preg_replace('/<tbody.*?>/',' ',$arr[0][0]);
$content=preg_replace('/<\/tbody>/',' ',$content);
$content=preg_replace('/<tr.*?>/',' ',$content);
$content=preg_replace('/<\/tr>/','|',$content);
$content=preg_replace('/<td.*?>/',' ',$content);
$content=preg_replace('/<\/td>/',' ',$content);
$content=preg_replace('/<span.*?>/',' ',$content);
$content=preg_replace('/<\/span>/',' ',$content);
$content=preg_replace('/<a.*?>/',' ',$content);
$content=preg_replace('/<\/a>/',' ',$content);
$content=preg_replace ( "/\s(?=\s)/","\\1", $content);
$content=substr($content,0,strlen($content)-2);
$content=explode('|',$content);
foreach ($content as $key => $value) {
$value=trim($value);
$value=explode(' ',$value);
$content[$key]=$value;
}
$foreignwhere=array('EURUSD','GBPUSD','USDJPY','USDSEK','USDCAD','AUDUSD','CHFUSD');
foreach ($content as $k=>$v){
if(in_array($v[0], $foreignwhere)){
$foreign[]=$v;
}
}
foreach ($foreign as $k=>$v){
$data['code']=$v[0];
$data['name']=iconv('GB2312','UTF-8',$v[1]);
$data['price']=$v[2];
$data['change']=$v[3];
$data['opened']=$v[4];
$data['max']=$v[5];
$data['min']=$v[6];
$data['prec']=$v[7];
$data['buy']=$v[8];
$data['sell']=$v[9];
$data['time']=time();
M('foreign')->add($data);
}
echo "基本汇率数据注入完成！";
}