10个实用的PHP代码片段
作为一个正常的程序员，会好几种语言是十分正常的，相信大部分程序员也都会编写几句PHP程序；如果你是WEB程序员，那么PHP是必备的一门语言，即使你没用它开发过大型软件项目，也一定多少了解它的语法。
尽管PHP经常被人诟病，被人贬低，被人当玩笑开，事实证明，PHP是全世界网站开发中使用率最高的编程语言。
PHP最大的缺点是太简单，语法不严谨，框架体系很弱，但这也是它最大的优点，一个有点编程背景的普通人，只需要学习PHP半天时间，就可以上手开始开发web应用了。
网上有人总结几种编程语言的特点，我觉得也挺有道理的：
- PHP就是： Quick and Dirty
- Java就是： Beauty and Slowly
- Ruby就是： Quick and Beauty
- python就是： Quick and Simple
在PHP的流行普及中，网上总结出了很多实用的PHP代码片段，这些代码片段在当你遇到类似的问题时，粘贴过去就可以使用，非常的高效，非常的省时省力。将这些程序员前辈总结出的优秀代码放到自己的知识库中，是一个善于学习的程序员的好习惯。
一、黑名单过滤
function is_spam($text, $file, $split = ':', $regex = false){ $handle = fopen($file, 'rb'); $contents = fread($handle, filesize($file)); fclose($handle); $lines = explode("n", $contents); $arr = array(); foreach($lines as $line){ list($word, $count) = explode($split, $line); if($regex) $arr[$word] = $count; else $arr[preg_quote($word)] = $count; } preg_match_all("~".implode('|', array_keys($arr))."~", $text, $matches); $temp = array(); foreach($matches[0] as $match){ if(!in_array($match, $temp)){ $temp[$match] = $temp[$match] + 1; if($temp[$match] >= $arr[$word]) return true; } } return false; } $file = 'spam.txt'; $str = 'This string has cat, dog word'; if(is_spam($str, $file)) echo 'this is spam'; else echo 'this is not spam'; 输出：
ab:3 dog:3 cat:2 monkey:2
二、随机颜色生成器
function randomColor() { $str = '#'; for($i = 0 ; $i < 6 ; $i++) { $randNum = rand(0 , 15); switch ($randNum) { case 10: $randNum = 'A'; break; case 11: $randNum = 'B'; break; case 12: $randNum = 'C'; break; case 13: $randNum = 'D'; break; case 14: $randNum = 'E'; break; case 15: $randNum = 'F'; break; } $str .= $randNum; } return $str; } $color = randomColor(); 三、从网络下载文件
set_time_limit(0); // Supports all file types // URL Here: $url = 'http://somsite.com/some_video.flv'; $pi = pathinfo($url); $ext = $pi['extension']; $name = $pi['filename']; // create a new cURL resource $ch = curl_init(); // set URL and other appropriate options curl_setopt($ch, CURLOPT_URL, $url); curl_setopt($ch, CURLOPT_HEADER, false); curl_setopt($ch, CURLOPT_BINARYTRANSFER, true); curl_setopt($ch, CURLOPT_AUTOREFERER, true); curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true); curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); // grab URL and pass it to the browser $opt = curl_exec($ch); // close cURL resource, and free up system resources curl_close($ch); $saveFile = $name.'.'.$ext; if(preg_match("/[^0-9a-z._-]/i", $saveFile)) $saveFile = md5(microtime(true)).'.'.$ext; $handle = fopen($saveFile, 'wb'); fwrite($handle, $opt); fclose($handle); 四、Alexa/Google Page Rank
function page_rank($page, $type = 'alexa'){ switch($type){ case 'alexa': $url = 'http://alexa.com/siteinfo/'; $handle = fopen($url.$page, 'r'); break; case 'google': $url = 'http://google.com/search?client=navclient-auto&ch=6-1484155081&features=Rank&q=info:'; $handle = fopen($url.'http://'.$page, 'r'); break; } $content = stream_get_contents($handle); fclose($handle); $content = preg_replace("~(n|t|ss+)~",'', $content); switch($type){ case 'alexa': if(preg_match('~<div class="data (down|up)"><img.+?>(.+?) </div>~im',$content,$matches)){ return $matches[2]; }else{ return FALSE; } break; case 'google': $rank = explode(':',$content); if($rank[2] != '') return $rank[2]; else return FALSE; break; default: return FALSE; break; } } // Alexa Page Rank: echo 'Alexa Rank: '.page_rank('techug.com'); echo ' '; // Google Page Rank echo 'Google Rank: '.page_rank('techug.com', 'google'); 五、强制下载文件
$filename = $_GET['file']; //Get the fileid from the URL // Query the file ID $query = sprintf("SELECT * FROM tableName WHERE id = '%s'",mysql_real_escape_string($filename)); $sql = mysql_query($query); if(mysql_num_rows($sql) > 0){ $row = mysql_fetch_array($sql); // Set some headers header("Pragma: public"); header("Expires: 0"); header("Cache-Control: must-revalidate, post-check=0, pre-check=0"); header("Content-Type: application/force-download"); header("Content-Type: application/octet-stream"); header("Content-Type: application/download"); header("Content-Disposition: attachment; filename=".basename($row['FileName']).";"); header("Content-Transfer-Encoding: binary"); header("Content-Length: ".filesize($row['FileName'])); @readfile($row['FileName']); exit(0); }else{ header("Location: /"); exit; } 六、通过Email显示用户的Gravatar头像
$gravatar_link = 'http://www.gravatar.com/avatar/' . md5($comment_author_email) . '?s=32'; echo '<img src="' . $gravatar_link . '" />';
七、通过cURL获取RSS订阅数
$ch = curl_init(); curl_setopt($ch,CURLOPT_URL,'https://feedburner.google.com/api/awareness/1.0/GetFeedData?id=7qkrmib4r9rscbplq5qgadiiq4'); curl_setopt($ch,CURLOPT_RETURNTRANSFER,1); curl_setopt($ch,CURLOPT_CONNECTTIMEOUT,2); $content = curl_exec($ch); $subscribers = get_match('/circulation="(.*)"/isU',$content); curl_close($ch); 八、时间差异计算函数
function ago($time) { $periods = array("second", "minute", "hour", "day", "week", "month", "year", "decade"); $lengths = array("60","60","24","7","4.35","12","10"); $now = time(); $difference = $now - $time; $tense = "ago"; for($j = 0; $difference >= $lengths[$j] && $j < count($lengths)-1; $j++) { $difference /= $lengths[$j]; } $difference = round($difference); if($difference != 1) { $periods[$j].= "s"; } return "$difference $periods[$j] 'ago' "; } 九、裁剪图片
$filename= "test.jpg"; list($w, $h, $type, $attr) = getimagesize($filename); $src_im = imagecreatefromjpeg($filename); $src_x = '0'; // begin x $src_y = '0'; // begin y $src_w = '100'; // width $src_h = '100'; // height $dst_x = '0'; // destination x $dst_y = '0'; // destination y $dst_im = imagecreatetruecolor($src_w, $src_h); $white = imagecolorallocate($dst_im, 255, 255, 255); imagefill($dst_im, 0, 0, $white); imagecopy($dst_im, $src_im, $dst_x, $dst_y, $src_x, $src_y, $src_w, $src_h); header("Content-type: image/png"); imagepng($dst_im); imagedestroy($dst_im); 十、检查网站是否宕机
function Visit($url){ $agent = "Mozilla/4.0 (compatible; MSIE 5.01; Windows NT 5.0)";$ch=curl_init(); curl_setopt ($ch, CURLOPT_URL,$url ); curl_setopt($ch, CURLOPT_USERAGENT, $agent); curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 1); curl_setopt ($ch,CURLOPT_VERBOSE,false); curl_setopt($ch, CURLOPT_TIMEOUT, 5); curl_setopt($ch,CURLOPT_SSL_VERIFYPEER, FALSE); curl_setopt($ch,CURLOPT_SSLVERSION,3); curl_setopt($ch,CURLOPT_SSL_VERIFYHOST, FALSE); $page=curl_exec($ch); //echo curl_error($ch); $httpcode = curl_getinfo($ch, CURLINFO_HTTP_CODE); curl_close($ch); if($httpcode>=200 && $httpcode<300) return true; else return false; } if (Visit("http://www.google.com")) echo "Website OK"."n"; else echo "Website DOWN";