一、查看邮件是否已被阅读
当你在发送邮件时，你或许很想知道该邮件是否被对方已阅读。这里有段非常有趣的代码片段能够显示对方IP地址记录阅读的实际日期和时间。
01.<?
02.error_reporting(0);
03.Header("Content-Type: image/jpeg");
04.
05.//Get IP
06.if (!emptyempty($_SERVER[‘HTTP_CLIENT_IP‘]))
07.{
08.$ip=$_SERVER[‘HTTP_CLIENT_IP‘];
09.}
10.elseif (!emptyempty($_SERVER[‘HTTP_X_FORWARDED_FOR‘]))
11.{
12.$ip=$_SERVER[‘HTTP_X_FORWARDED_FOR‘];
13.}
14.else
15.{
16.$ip=$_SERVER[‘REMOTE_ADDR‘];
17.}
18.
19.//Time
20.$actual_time = time();
21.$actual_day = date(‘Y.m.d‘, $actual_time);
22.$actual_day_chart = date(‘d/m/y‘, $actual_time);
23.$actual_hour = date(‘H:i:s‘, $actual_time);
24.
25.//GET Browser
26.$browser = $_SERVER[‘HTTP_USER_AGENT‘];
27.
28.//LOG
29.$myFile = "log.txt";
30.$fh = fopen($myFile, ‘a+‘);
31.$stringData = $actual_day . ‘ ‘ . $actual_hour . ‘ ‘ . $ip . ‘ ‘ . $browser . ‘ ‘ ."\r\n";
32.fwrite($fh, $stringData);
33.fclose($fh);
34.
35.//Generate Image (Es. dimesion is 1x1)
36.$newimage = ImageCreate(1,1);
37.$grigio = ImageColorAllocate($newimage,255,255,255);
38.ImageJPEG($newimage);
39.ImageDestroy($newimage);
40.
41.?>
二、从网页中提取关键字
一段伟大的代码片段能够轻松的从网页中提取关键字。
01.$meta = get_meta_tags(‘http://www.emoticode.net/‘);
02.$keywords = $meta[‘keywords‘];
03.// Split keywords
04.$keywords = explode(‘,‘, $keywords );
05.// Trim them
06.$keywords = array_map( ‘trim‘, $keywords );
07.// Remove empty values
08.$keywords = array_filter( $keywords );
09.
10.print_r( $keywords );
三、查找页面上的所有链接
使用DOM，你可以轻松从任何页面上抓取链接，代码示例如下：
01.$html = file_get_contents(‘http://www.php100.com‘);
02.
03.$dom = new DOMDocument();
04.@$dom->loadHTML($html);
05.
06.// grab all the on the page
07.$xpath = new DOMXPath($dom);
08.$hrefs = $xpath->evaluate("/html/body//a");
09.
10.for ($i = 0; $i < $hrefs->length; $i++) {
11.$href = $hrefs->item($i);
12.$url = $href->getAttribute(‘href‘);
13.echo $url.‘<br />‘;
14.}
四、自动转换URL，跳转至超链接
在WordPress中，如果你想自动转换URL，跳转至超链接页面，你可以利用内置的函数make_clickable()执行此操作。如果你想基于WordPress之外操作该程序，那么你可以参考wp-includes/formatting.php源代码。
01.function _make_url_clickable_cb($matches) {
02.$ret = ‘‘;
03.$url = $matches[2];
04.
05.if ( emptyempty($url) )
06.return $matches[0];
07.// removed trailing [.,;:] from URL
08.if ( in_array(substr($url, -1), array(‘.‘, ‘,‘, ‘;‘, ‘:‘)) === true ) {
09.$ret = substr($url, -1);
10.$url = substr($url, 0, strlen($url)-1);
11.}
12.return $matches[1] . "<a href=\"$url\" rel=\"nofollow\">$url</a>" . $ret;
13.}
14.
15.function _make_web_ftp_clickable_cb($matches) {
16.$ret = ‘‘;
17.$dest = $matches[2];
18.$dest = ‘http://‘ . $dest;
19.
20.if ( emptyempty($dest) )
21.return $matches[0];
22.// removed trailing [,;:] from URL
23.if ( in_array(substr($dest, -1), array(‘.‘, ‘,‘, ‘;‘, ‘:‘)) === true ) {
24.$ret = substr($dest, -1);
25.$dest = substr($dest, 0, strlen($dest)-1);
26.}
27.return $matches[1] . "<a href=\"$dest\" rel=\"nofollow\">$dest</a>" . $ret;
28.}
29.
30.function _make_email_clickable_cb($matches) {
31.$email = $matches[2] . ‘@‘ . $matches[3];
32.return $matches[1] . "<a href=\"mailto:$email\">$email</a>";
33.}
34.
35.function make_clickable($ret) {
36.$ret = ‘ ‘ . $ret;
37.// in testing, using arrays here was found to be faster
38.$ret = preg_replace_callback(‘#([\s>])([\w]+?://[\w\\x80-\\xff\#$%&~/.\-;:=,?@\[\]+]*)#is‘, ‘_make_url_clickable_cb‘, $ret);
39.$ret = preg_replace_callback(‘#([\s>])((www|ftp)\.[\w\\x80-\\xff\#$%&~/.\-;:=,?@\[\]+]*)#is‘, ‘_make_web_ftp_clickable_cb‘, $ret);
40.$ret = preg_replace_callback(‘#([\s>])([.0-9a-z_+-]+)@(([0-9a-z-]+\.)+[0-9a-z]{2,})#i‘, ‘_make_email_clickable_cb‘, $ret);
41.
42.// this one is not in an array because we need it to run last, for cleanup of accidental links within links
43.$ret = preg_replace("#(<a( [^>]+?>|>))<a [^>]+?>([^>]+?)</a></a>#i", "$1$3</a>",$ret);
44.$ret = trim($ret);
45.return $ret;
46.}
五、创建数据URL
数据URL可以直接嵌入到HTML/CSS/JS中，以节省大量的 HTTP请求。 下面的这段代码可利用$file轻松创建数据URL。
1.function data_uri($file, $mime) {
2.$contents=file_get_contents($file);
3.$base64=base64_encode($contents);
4.echo "data:$mime;base64,$base64";
5.}
六、从服务器上下载&保存一个远程图片
当你在搭建网站时，从远程服务器下载某张图片并且将其保存在自己的服务器上，这一操作会经常用到。代码如下：
1.$image = file_get_contents(‘http://www.php100.com/image.jpg‘);
2.file_put_contents(‘/images/image.jpg‘, $image);//Where to save the image
七、移除Remove Microsoft Word HTML Tag
当你使用Microsoft Word会创建许多Tag，比如font，span，style，class等。这些标签对于Word本身而言是非常有用的，但是当你从Word粘贴至网页时，你会发现很多无用的Tag。因此，下面的这段代码可帮助你删除所有无用的Word HTML Tag。
01.function cleanHTML($html) {
02./// <summary>
03./// Removes all FONT and SPAN tags, and all Class and Style attributes.
04./// Designed to get rid of non-standard Microsoft Word HTML tags.
05./// </summary>
06.// start by completely removing all unwanted tags
07.
08.$html = ereg_replace("<(/)?(font|span|del|ins)[^>]*>","",$html);
09.
10.// then run another pass over the html (twice), removing unwanted attributes
11.
12.$html = ereg_replace("<([^>]*)(class|lang|style|size|face)=("[^"]*"|‘[^‘]*‘|[^>]+)([^>]*)>","<\1>",$html);
13.$html = ereg_replace("<([^>]*)(class|lang|style|size|face)=("[^"]*"|‘[^‘]*‘|[^>]+)([^>]*)>","<\1>",$html);
14.
15.return $html
16.}
八、检测浏览器语言
如果你的网站上有多种语言，那么可以使用这段代码作为默认的语言来检测浏览器语言。该段代码将返回浏览器客户端使用的初始语言。
01.function get_client_language($availableLanguages, $default=‘en‘){
02.if (isset($_SERVER[‘HTTP_ACCEPT_LANGUAGE‘])) {
03.$langs=explode(‘,‘,$_SERVER[‘HTTP_ACCEPT_LANGUAGE‘]);
04.
05.foreach ($langs as $value){
06.$choice=substr($value,0,2);
07.if(in_array($choice, $availableLanguages)){
08.return $choice;
09.}
10.}
11.}
12.return $default;
13.}
九、显示Facebook 粉丝数量
如果你的网站或者博客上有内链的Facebook页面，你或许想知道拥有多少粉丝。这段代码将帮助你查看Facebook粉丝数，记住，别忘了在你的页面ID第二行添加该段代码。
1.<?php
2.$page_id = "YOUR PAGE-ID";
3.$xml = @simplexml_load_file("http://api.facebook.com/restserver.php?method=facebook.fql.query&;query=SELECT%20fan_count%20FROM%20page%20WHERE%20page_id=".$page_id."")or die ("a lot");
4.$fans = $xml->page->fan_count;
5.echo $fans;
6.?>