本文目录一览：
- 1、php中curl爬虫 怎么样通过网页获取所有链接
- 2、php获取数据为什么curl获取不完整？而用file_get_contents能获取完整？
- 3、php如何获取通过CURL或file_get_contents抓取者的IP地址
- 4、php curl 为什么比file
php中curl爬虫 怎么样通过网页获取所有链接
本文承接上面两篇，本篇中的示例要调用到前两篇中的函数，做一个简单的URL采集。一般php采集网络数据会用file_get_contents、file和cURL。不过据说cURL会比file_get_contents、file更快更专业，更适合采集。今天就试试用cURL来获取网页上的所有链接。示例如下：
?php
/*
* 使用curl 采集hao123.com下的所有链接。
*/
include_once('function.php');
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, '');
// 只需返回HTTP header
curl_setopt($ch, CURLOPT_HEADER, 1);
// 页面内容我们并不需要
// curl_setopt($ch, CURLOPT_NOBODY, 1);
// 返回结果，而不是输出它
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
$html = curl_exec($ch);
$info = curl_getinfo($ch);
if ($html === false) {
echo "cURL Error: " . curl_error($ch);
}
curl_close($ch);
$linkarr = _striplinks($html);
// 主机部分，补全用
$host = '';
if (is_array($linkarr)) {
foreach ($linkarr as $k = $v) {
$linkresult[$k] = _expandlinks($v, $host);
}
}
printf("p此页面的所有链接为：/ppre%s/pren", var_export($linkresult , true));
?
function.php内容如下（即为上两篇中两个函数的合集）：
?php
function _striplinks($document) {
preg_match_all("'s*as.*?hrefs*=s*(["'])?(?(1) (.*?)\1 | ([^s]+))'isx", $document, $links);
// catenate the non-empty matches from the conditional subpattern
while (list($key, $val) = each($links[2])) {
if (!empty($val))
$match[] = $val;
} while (list($key, $val) = each($links[3])) {
if (!empty($val))
$match[] = $val;
}
// return the links
return $match;
}
/*===================================================================*
Function: _expandlinks
Purpose: expand each link into a fully qualified URL
Input: $links the links to qualify
$URI the full URI to get the base from
Output: $expandedLinks the expanded links
*===================================================================*/
function _expandlinks($links,$URI)
{
$URI_PARTS = parse_url($URI);
$host = $URI_PARTS["host"];
preg_match("/^[^?]+/",$URI,$match);
$match = preg_replace("|/[^/.]+.[^/.]+$|","",$match[0]);
$match = preg_replace("|/$|","",$match);
$match_part = parse_url($match);
$match_root =
$match_part["scheme"]."://".$match_part["host"];
$search = array( "|^http://".preg_quote($host)."|i",
"|^(/)|i",
"|^(?!http://)(?!mailto:)|i",
"|/./|",
"|/[^/]+/../|"
);
$replace = array( "",
$match_root."/",
$match."/",
"/",
"/"
);
$expandedLinks = preg_replace($search,$replace,$links);
return $expandedLinks;
}
?
php获取数据为什么curl获取不完整？而用file_get_contents能获取完整？
因为，PHP CURL库默认1024字节的长度不等待数据的返回，所以你那段代码需增加一项配置：
curl_setopt($ch, CURLOPT_HTTPHEADER, array('Expect:'));
给你一个更全面的封装方法：
function req_curl($url, $status = null, $options = array())
{
$res = '';
$options = array_merge(array(
'follow_local' = true,
'timeout' = 30,
'max_redirects' = 4,
'binary_transfer' = false,
'include_header' = false,
'no_body' = false,
'cookie_location' = dirname(__FILE__) . '/cookie',
'useragent' = 'Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1',
'post' = array() ,
'referer' = null,
'ssl_verifypeer' = 0,
'ssl_verifyhost' = 0,
'headers' = array(
'Expect:'
) ,
'auth_name' = '',
'auth_pass' = '',
'session' = false
) , $options);
$options['url'] = $url;
$s = curl_init();
if (!$s) return false;
curl_setopt($s, CURLOPT_URL, $options['url']);
curl_setopt($s, CURLOPT_HTTPHEADER, $options['headers']);
curl_setopt($s, CURLOPT_SSL_VERIFYPEER, $options['ssl_verifypeer']);
curl_setopt($s, CURLOPT_SSL_VERIFYHOST, $options['ssl_verifyhost']);
curl_setopt($s, CURLOPT_TIMEOUT, $options['timeout']);
curl_setopt($s, CURLOPT_MAXREDIRS, $options['max_redirects']);
curl_setopt($s, CURLOPT_RETURNTRANSFER, true);
curl_setopt($s, CURLOPT_FOLLOWLOCATION, $options['follow_local']);
curl_setopt($s, CURLOPT_COOKIEJAR, $options['cookie_location']);
curl_setopt($s, CURLOPT_COOKIEFILE, $options['cookie_location']);
if (!empty($options['auth_name']) is_string($options['auth_name']))
{
curl_setopt($s, CURLOPT_USERPWD, $options['auth_name'] . ':' . $options['auth_pass']);
}
if (!empty($options['post']))
{
curl_setopt($s, CURLOPT_POST, true);
curl_setopt($s, CURLOPT_POSTFIELDS, $options['post']);
//curl_setopt($s, CURLOPT_POSTFIELDS, array('username' = 'aeon', 'password' = '111111'));
}
if ($options['include_header'])
{
curl_setopt($s, CURLOPT_HEADER, true);
}
if ($options['no_body'])
{
curl_setopt($s, CURLOPT_NOBODY, true);
}
if ($options['session'])
{
curl_setopt($s, CURLOPT_COOKIESESSION, true);
curl_setopt($s, CURLOPT_COOKIE, $options['session']);
}
curl_setopt($s, CURLOPT_USERAGENT, $options['useragent']);
curl_setopt($s, CURLOPT_REFERER, $options['referer']);
$res = curl_exec($s);
$status = curl_getinfo($s, CURLINFO_HTTP_CODE);
curl_close($s);
return $res;
}
php如何获取通过CURL或file_get_contents抓取者的IP地址
百度搜一下防止采集方面的知识，CURL或file_get_contents可以模拟用户行为，获取ip跟普通用户ip其实是一样的，关键是怎么去区别他们，这就需要在客户端做手脚，一般都用js来在客户端做手脚来区别。
php curl 为什么比file
curl为什么比file_get_contents慢？
还是啥问题？
呃，问太多，我也不懂，反正用就是了，听从大神的测试结果，或者自己不服了，也去跑个测试，实在还想问，那就读源代码~
