PHP二十一段救命代碼
1. PHP可閱讀隨機字符串
此代碼將創建一個可閱讀的字符串，使其更接近詞典中的單詞，實用且具有密碼驗證功能。
- /**************
- *@length - length of random string (must be a multiple of 2)
- **************/
- function readable_random_string($length = 6){
- $conso=array("b","c","d","f","g","h","j","k","l",
- "m","n","p","r","s","t","v","w","x","y","z");
- $vocal=array("a","e","i","o","u");
- $password="";
- srand ((double)microtime()*1000000);
- $max = $length/2;
- for($i=1; $i<=$max; $i++)
- {
- $password.=$conso[rand(0,19)];
- $password.=$vocal[rand(0,4)];
- }
- return $password;
- }
2. PHP生成一個隨機字符串
如果不需要可閱讀的字符串，使用此函數替代，即可創建一個隨機字符串，作為用戶的隨機密碼等。
- /*************
- *@l - length of random string
- */
- function generate_rand($l){
- $c= "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
- srand((double)microtime()*1000000);
- for($i=0; $i<$l; $i++) {
- $rand.= $c[rand()%strlen($c)];
- }
- return $rand;
- }
3. PHP編碼電子郵件地址
使用此代碼，可以將任何電子郵件地址編碼為 html 字符實體，以防止被垃圾郵件程序收集。
- function encode_email($email='info@domain.com', $linkText='Contact Us', $attrs ='class="emailencoder"' )
- {
- // remplazar aroba y puntos
- $email = str_replace('@', '@', $email);
- $email = str_replace('.', '.', $email);
- $email = str_split($email, 5);
- $linkText = str_replace('@', '@', $linkText);
- $linkText = str_replace('.', '.', $linkText);
- $linkText = str_split($linkText, 5);
- $part1 = '<a href="ma';
- $part2 = 'ilto:';
- $part3 = '" '. $attrs .' >';
- $part4 = '</a>';
- $encoded = '<script type="text/javascript">';
- $encoded .= "document.write('$part1');";
- $encoded .= "document.write('$part2');";
- foreach($email as $e)
- {
- $encoded .= "document.write('$e');";
- }
- $encoded .= "document.write('$part3');";
- foreach($linkText as $l)
- {
- $encoded .= "document.write('$l');";
- }
- $encoded .= "document.write('$part4');";
- $encoded .= '</script>';
- return $encoded;
- }
4. PHP驗證郵件地址
電子郵件驗證也許是中最常用的網頁表單驗證，此代碼除了驗證電子郵件地址，也可以選擇檢查郵件域所屬 DNS 中的 MX 記錄，使郵件驗證功能更加強大。
- function is_valid_email($email, $test_mx = false)
- {
- if(eregi("^([_a-z0-9-]+)(.[_a-z0-9-]+)*@([a-z0-9-]+)(.[a-z0-9-]+)*(.[a-z]{2,4})$", $email))
- if($test_mx)
- {
- list($username, $domain) = split("@", $email);
- return getmxrr($domain, $mxrecords);
- }
- else
- return true;
- else
- return false;
- }
5. PHP列出目錄內容
- function list_files($dir)
- {
- if(is_dir($dir))
- {
- if($handle = opendir($dir))
- {
- while(($file = readdir($handle)) !== false)
- {
- if($file != "." && $file != ".." && $file != "Thumbs.db")
- {
- echo '<a target="_blank" href="'.$dir.$file.'">'.$file.'</a><br>'."n";
- }
- }
- closedir($handle);
- }
- }
- }
6. PHP銷毀目錄
刪除一個目錄，包括它的內容。
- /*****
- *@dir - Directory to destroy
- *@virtual[optional]- whether a virtual directory
- */
- function destroyDir($dir, $virtual = false)
- {
- $ds = DIRECTORY_SEPARATOR;
- $dir = $virtual ? realpath($dir) : $dir;
- $dir = substr($dir, -1) == $ds ? substr($dir, 0, -1) : $dir;
- if (is_dir($dir) && $handle = opendir($dir))
- {
- while ($file = readdir($handle))
- {
- if ($file == '.' || $file == '..')
- {
- continue;
- }
- elseif (is_dir($dir.$ds.$file))
- {
- destroyDir($dir.$ds.$file);
- }
- else
- {
- unlink($dir.$ds.$file);
- }
- }
- closedir($handle);
- rmdir($dir);
- return true;
- }
- else
- {
- return false;
- }
- }
7. PHP解析 JSON 數據
與大多數流行的 Web 服務如 twitter 通過開放 API 來提供數據一樣，它總是能夠知道如何解析 API 數據的各種傳送格式，包括 JSON，XML 等等。
- $json_string='{"id":1,"name":"foo","email":"foo@foobar.com","interest":["wordpress","php"]} ';
- $obj=json_decode($json_string);
- echo $obj->name; //prints foo
- echo $obj->interest[1]; //prints php
8. PHP解析 XML 數據
- //xml string
- $xml_string="<?xml version='1.0'?>
- <users>
- <user id='398'>
- <name>Foo</name>
- <email>foo@bar.com</name>
- </user>
- <user id='867'>
- <name>Foobar</name>
- <email>foobar@foo.com</name>
- </user>
- </users>";
- //load the xml string using simplexml
- $xml = simplexml_load_string($xml_string);
- //loop through the each node of user
- foreach ($xml->user as $user)
- {
- //access attribute
- echo $user['id'], ' ';
- //subnodes are accessed by -> operator
- echo $user->name, ' ';
- echo $user->email, '<br />';
- }
9. PHP創建日志縮略名
創建用戶友好的日志縮略名。
- function create_slug($string){
- $slug=preg_replace('/[^A-Za-z0-9-]+/', '-', $string);
- return $slug;
- }
10. PHP獲取客戶端真實 IP 地址
該函數將獲取用戶的真實 IP 地址，即便他使用代理服務器。
- function getRealIpAddr()
- {
- if (!emptyempty($_SERVER['HTTP_CLIENT_IP']))
- {
- $ip=$_SERVER['HTTP_CLIENT_IP'];
- }
- elseif (!emptyempty($_SERVER['HTTP_X_FORWARDED_FOR']))
- //to check ip is pass from proxy
- {
- $ip=$_SERVER['HTTP_X_FORWARDED_FOR'];
- }
- else
- {
- $ip=$_SERVER['REMOTE_ADDR'];
- }
- return $ip;
- }
11. PHP強制性文件下載
為用戶提供強制性的文件下載功能。
- /********************
- *@file - path to file
- */
- function force_download($file)
- {
- if ((isset($file))&&(file_exists($file))) {
- header("Content-length: ".filesize($file));
- header('Content-Type: application/octet-stream');
- header('Content-Disposition: attachment; filename="' . $file . '"');
- readfile("$file");
- } else {
- echo "No file selected";
- }
- }
12. PHP創建標簽云
- function getCloud( $data = array(), $minFontSize = 12, $maxFontSize = 30 )
- {
- $minimumCount = min( array_values( $data ) );
- $maximumCount = max( array_values( $data ) );
- $spread = $maximumCount - $minimumCount;
- $cloudHTML = '';
- $cloudTags = array();
- $spread == 0 && $spread = 1;
- foreach( $data as $tag => $count )
- {
- $size = $minFontSize + ( $count - $minimumCount )
- * ( $maxFontSize - $minFontSize ) / $spread;
- $cloudTags[] = '<a style="font-size: ' . floor( $size ) . 'px'
- . '" href="#" title="'' . $tag .
- '' returned a count of ' . $count . '">'
- . htmlspecialchars( stripslashes( $tag ) ) . '</a>';
- }
- return join( "n", $cloudTags ) . "n";
- }
- /**************************
- **** Sample usage ***/
- $arr = Array('Actionscript' => 35, 'Adobe' => 22, 'Array' => 44, 'Background' => 43,
- 'Blur' => 18, 'Canvas' => 33, 'Class' => 15, 'Color Palette' => 11, 'Crop' => 42,
- 'Delimiter' => 13, 'Depth' => 34, 'Design' => 8, 'Encode' => 12, 'Encryption' => 30,
- 'Extract' => 28, 'Filters' => 42);
- echo getCloud($arr, 12, 36);
13. PHP尋找兩個字符串的相似性
PHP 提供了一個極少使用的 similar_text 函數，但此函數非常有用，用于比較兩個字符串并返回相似程度的百分比。
- similar_text($string1, $string2, $percent);
- //$percent will have the percentage of similarity
14. PHP在應用程序中使用 Gravatar 通用頭像
隨著 WordPress 越來越普及，Gravatar 也隨之流行。由于 Gravatar 提供了易于使用的 API，將其納入應用程序也變得十分方便。
- /******************
- *@email - Email address to show gravatar for
- *@size - size of gravatar
- *@default - URL of default gravatar to use
- *@rating - rating of Gravatar(G, PG, R, X)
- */
- function show_gravatar($email, $size, $default, $rating)
- {
- echo '<img src="http://www.gravatar.com/avatar.php?gravatar_id='.md5($email).
- '&default='.$default.'&size='.$size.'&rating='.$rating.'" width="'.$size.'px"
- height="'.$size.'px" />';
- }
15. PHP在字符斷點處截斷文字
所謂斷字 (word break)，即一個單詞可在轉行時斷開的地方。這一函數將在斷字處截斷字符串。
- // Original PHP code by Chirp Internet: www.chirp.com.au
- // Please acknowledge use of this code by including this header.
- function myTruncate($string, $limit, $break=".", $pad="...") {
- // return with no change if string is shorter than $limit
- if(strlen($string) <= $limit)
- return $string;
- // is $break present between $limit and the end of the string?
- if(false !== ($breakpoint = strpos($string, $break, $limit))) {
- if($breakpoint < strlen($string) - 1) {
- $string = substr($string, 0, $breakpoint) . $pad;
- }
- }
- return $string;
- }
- /***** Example ****/
- $short_string=myTruncate($long_string, 100, ' ');
16. PHP文件 Zip 壓縮
- /* creates a compressed zip file */
- function create_zip($files = array(),$destination = '',$overwrite = false) {
- //if the zip file already exists and overwrite is false, return false
- if(file_exists($destination) && !$overwrite) { return false; }
- //vars
- $valid_files = array();
- //if files were passed in...
- if(is_array($files)) {
- //cycle through each file
- foreach($files as $file) {
- //make sure the file exists
- if(file_exists($file)) {
- $valid_files[] = $file;
- }
- }
- }
- //if we have good files...
- if(count($valid_files)) {
- //create the archive
- $zip = new ZipArchive();
- if($zip->open($destination,$overwrite ? ZIPARCHIVE::OVERWRITE : ZIPARCHIVE::CREATE) !== true) {
- return false;
- }
- //add the files
- foreach($valid_files as $file) {
- $zip->addFile($file,$file);
- }
- //debug
- //echo 'The zip archive contains ',$zip->numFiles,' files with a status of ',$zip->status;
- //close the zip -- done!
- $zip->close();
- //check to make sure the file exists
- return file_exists($destination);
- }
- else
- {
- return false;
- }
- }
- /***** Example Usage ***/
- $files=array('file1.jpg', 'file2.jpg', 'file3.gif');
- create_zip($files, 'myzipfile.zip', true);
17. PHP解壓縮 Zip 文件
- /**********************
- *@file - path to zip file
- *@destination - destination directory for unzipped files
- */
- function unzip_file($file, $destination){
- // create object
- $zip = new ZipArchive() ;
- // open archive
- if ($zip->open($file) !== TRUE) {
- die (’Could not open archive’);
- }
- // extract contents to destination directory
- $zip->extractTo($destination);
- // close archive
- $zip->close();
- echo 'Archive extracted to directory';
- }
18. PHP為 URL 地址預設 http 字符串
有時需要接受一些表單中的網址輸入，但用戶很少添加 http:// 字段，此代碼將為網址添加該字段。
- if (!preg_match("/^(http|ftp):/", $_POST['url'])) {
- $_POST['url'] = 'http://'.$_POST['url'];
- }
19. PHP將網址字符串轉換成超級鏈接
該函數將 URL 和 E-mail 地址字符串轉換為可點擊的超級鏈接。
- function makeClickableLinks($text) {
- $text = eregi_replace('(((f|ht){1}tp://)[-a-zA-Z0-9@:%_+.~#?&//=]+)',
- '<a href="1">1</a>', $text);
- $text = eregi_replace('([[:space:]()[{}])(www.[-a-zA-Z0-9@:%_+.~#?&//=]+)',
- '1<a href="http://2">2</a>', $text);
- $text = eregi_replace('([_.0-9a-z-]+@([0-9a-z][0-9a-z-]+.)+[a-z]{2,3})',
- '<a href="mailto:1">1</a>', $text);
- return $text;
- }
20. PHP調整圖像尺寸
創建圖像縮略圖需要許多時間，此代碼將有助于了解縮略圖的邏輯。
- /**********************
- *@filename - path to the image
- *@tmpname - temporary path to thumbnail
- *@xmax - max width
- *@ymax - max height
- */
- function resize_image($filename, $tmpname, $xmax, $ymax)
- {
- $ext = explode(".", $filename);
- $ext = $ext[count($ext)-1];
- if($ext == "jpg" || $ext == "jpeg")
- $im = imagecreatefromjpeg($tmpname);
- elseif($ext == "png")
- $im = imagecreatefrompng($tmpname);
- elseif($ext == "gif")
- $im = imagecreatefromgif($tmpname);
- $x = imagesx($im);
- $y = imagesy($im);
- if($x <= $xmax && $y <= $ymax)
- return $im;
- if($x >= $y) {
- $newx = $xmax;
- $newy = $newx * $y / $x;
- }
- else {
- $newy = $ymax;
- $newx = $x / $y * $newy;
- }
- $im2 = imagecreatetruecolor($newx, $newy);
- imagecopyresized($im2, $im, 0, 0, 0, 0, floor($newx), floor($newy), $x, $y);
- return $im2;
- }
21. PHP檢測 ajax 請求
大多數的 JavaScript 框架如 jquery，Mootools 等，在發出 Ajax 請求時，都會發送額外的 HTTP_X_REQUESTED_WITH 頭部信息，頭當他們一個ajax請求，因此你可以在服務器端偵測到 Ajax 請求。
標簽：北京網站制作 高端網站建設
- if(!emptyempty($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest'){
- //If AJAX Request Then
- }else{
- //something else
- }