再来二十一段救命的PHP代码

1. PHP可阅读随机字符串 此代码将创建一个可阅读的字符串,使其更接近词典中的单词,实用且具有密码验证功能。
  1. /**************
  2. *@length - length of random string (must be a multiple of 2)
  3. **************/
  4. function readable_random_string($length = 6){
  5. $conso=array("b","c","d","f","g","h","j","k","l",
  6. "m","n","p","r","s","t","v","w","x","y","z");
  7. $vocal=array("a","e","i","o","u");
  8. $password="";
  9. srand ((double)microtime()*1000000);
  10. $max = $length/2;
  11. for($i=1; $i<=$max; $i++)
  12. {
  13. $password.=$conso[rand(0,19)];
  14. $password.=$vocal[rand(0,4)];
  15. }
  16. return $password;
  17. }
2. PHP生成一个随机字符串 如果不需要可阅读的字符串,使用此函数替代,即可创建一个随机字符串,作为用户的随机密码等。
  1. /*************
  2. *@l - length of random string
  3. */
  4. function generate_rand($l){
  5. $c= "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
  6. srand((double)microtime()*1000000);
  7. for($i=0; $i<$l; $i++) {
  8. $rand.= $c[rand()%strlen($c)];
  9. }
  10. return $rand;
  11. }
3. PHP编码电子邮件地址 使用此代码,可以将任何电子邮件地址编码为 html 字符实体,以防止被垃圾邮件程序收集。
  1. function encode_email($email='info@domain.com', $linkText='Contact Us', $attrs ='class="emailencoder"' )
  2. {
  3. // remplazar aroba y puntos
  4. $email = str_replace('@', '&#64;', $email);
  5. $email = str_replace('.', '&#46;', $email);
  6. $email = str_split($email, 5);
  7. $linkText = str_replace('@', '&#64;', $linkText);
  8. $linkText = str_replace('.', '&#46;', $linkText);
  9. $linkText = str_split($linkText, 5);
  10. $part1 = '<a href="ma';
  11. $part2 = 'ilto&#58;';
  12. $part3 = '" '. $attrs .' >';
  13. $part4 = '</a>';
  14. $encoded = '<script type="text/javascript">';
  15. $encoded .= "document.write('$part1');";
  16. $encoded .= "document.write('$part2');";
  17. foreach($email as $e)
  18. {
  19. $encoded .= "document.write('$e');";
  20. }
  21. $encoded .= "document.write('$part3');";
  22. foreach($linkText as $l)
  23. {
  24. $encoded .= "document.write('$l');";
  25. }
  26. $encoded .= "document.write('$part4');";
  27. $encoded .= '</script>';
  28. return $encoded;
  29. }
4. PHP验证邮件地址 电子邮件验证也许是中最常用的网页表单验证,此代码除了验证电子邮件地址,也可以选择检查邮件域所属 DNS 中的 MX 记录,使邮件验证功能更加强大。
  1. function is_valid_email($email, $test_mx = false)
  2. {
  3. if(eregi("^([_a-z0-9-]+)(\.[_a-z0-9-]+)*@([a-z0-9-]+)(\.[a-z0-9-]+)*(\.[a-z]{2,4})$", $email))
  4. if($test_mx)
  5. {
  6. list($username, $domain) = split("@", $email);
  7. return getmxrr($domain, $mxrecords);
  8. }
  9. else
  10. return true;
  11. else
  12. return false;
  13. }
5. PHP列出目录内容
  1. function list_files($dir)
  2. {
  3. if(is_dir($dir))
  4. {
  5. if($handle = opendir($dir))
  6. {
  7. while(($file = readdir($handle)) !== false)
  8. {
  9. if($file != "." && $file != ".." && $file != "Thumbs.db")
  10. {
  11. echo '<a target="_blank" href="'.$dir.$file.'">'.$file.'</a><br>'."\n";
  12. }
  13. }
  14. closedir($handle);
  15. }
  16. }
  17. }
6. PHP销毁目录 删除一个目录,包括它的内容。
  1. /*****
  2. *@dir - Directory to destroy
  3. *@virtual[optional]- whether a virtual directory
  4. */
  5. function destroyDir($dir, $virtual = false)
  6. {
  7. $ds = DIRECTORY_SEPARATOR;
  8. $dir = $virtual ? realpath($dir) : $dir;
  9. $dir = substr($dir, -1) == $ds ? substr($dir, 0, -1) : $dir;
  10. if (is_dir($dir) && $handle = opendir($dir))
  11. {
  12. while ($file = readdir($handle))
  13. {
  14. if ($file == '.' || $file == '..')
  15. {
  16. continue;
  17. }
  18. elseif (is_dir($dir.$ds.$file))
  19. {
  20. destroyDir($dir.$ds.$file);
  21. }
  22. else
  23. {
  24. unlink($dir.$ds.$file);
  25. }
  26. }
  27. closedir($handle);
  28. rmdir($dir);
  29. return true;
  30. }
  31. else
  32. {
  33. return false;
  34. }
  35. }
7. PHP解析 JSON 数据 与大多数流行的 Web 服务如 twitter 通过开放 API 来提供数据一样,它总是能够知道如何解析 API 数据的各种传送格式,包括 JSON,XML 等等。
  1. $json_string='{"id":1,"name":"foo","email":"foo@foobar.com","interest":["wordpress","php"]} ';
  2. $obj=json_decode($json_string);
  3. echo $obj->name; //prints foo
  4. echo $obj->interest[1]; //prints php
8. PHP解析 XML 数据
  1. //xml string
  2. $xml_string="<?xml version='1.0'?>
  3. <users>
  4. <user >
  5. <name>Foo</name>
  6. <email>foo@bar.com</name>
  7. </user>
  8. <user >
  9. <name>Foobar</name>
  10. <email>foobar@foo.com</name>
  11. </user>
  12. </users>";
  13. //load the xml string using simplexml
  14. $xml = simplexml_load_string($xml_string);
  15. //loop through the each node of user
  16. foreach ($xml->user as $user)
  17. {
  18. //access attribute
  19. echo $user['id'], ' ';
  20. //subnodes are accessed by -> operator
  21. echo $user->name, ' ';
  22. echo $user->email, '<br />';
  23. }
9. PHP创建日志缩略名 创建用户友好的日志缩略名。
  1. function create_slug($string){
  2. $slug=preg_replace('/[^A-Za-z0-9-]+/', '-', $string);
  3. return $slug;
  4. }
10. PHP获取客户端真实 IP 地址 该函数将获取用户的真实 IP 地址,即便他使用代理服务器。
  1. function getRealIpAddr()
  2. {
  3. if (!emptyempty($_SERVER['HTTP_CLIENT_IP']))
  4. {
  5. $ip=$_SERVER['HTTP_CLIENT_IP'];
  6. }
  7. elseif (!emptyempty($_SERVER['HTTP_X_FORWARDED_FOR']))
  8. //to check ip is pass from proxy
  9. {
  10. $ip=$_SERVER['HTTP_X_FORWARDED_FOR'];
  11. }
  12. else
  13. {
  14. $ip=$_SERVER['REMOTE_ADDR'];
  15. }
  16. return $ip;
  17. }
11. PHP强制性文件下载 为用户提供强制性的文件下载功能。
  1. /********************
  2. *@file - path to file
  3. */
  4. function force_download($file)
  5. {
  6. if ((isset($file))&&(file_exists($file))) {
  7. header("Content-length: ".filesize($file));
  8. header('Content-Type: application/octet-stream');
  9. header('Content-Disposition: attachment; filename="' . $file . '"');
  10. readfile("$file");
  11. } else {
  12. echo "No file selected";
  13. }
  14. }
12. PHP创建标签云
  1. function getCloud( $data = array(), $minFontSize = 12, $maxFontSize = 30 )
  2. {
  3. $minimumCount = min( array_values( $data ) );
  4. $maximumCount = max( array_values( $data ) );
  5. $spread = $maximumCount - $minimumCount;
  6. $cloudHTML = '';
  7. $cloudTags = array();
  8. $spread == 0 && $spread = 1;
  9. foreach( $data as $tag => $count )
  10. {
  11. $size = $minFontSize + ( $count - $minimumCount )
  12. * ( $maxFontSize - $minFontSize ) / $spread;
  13. $cloudTags[] = '<a . floor( $size ) . 'px'
  14. . '" href="#" title="\'' . $tag .
  15. '\' returned a count of ' . $count . '">'
  16. . htmlspecialchars( stripslashes( $tag ) ) . '</a>';
  17. }
  18. return join( "\n", $cloudTags ) . "\n";
  19. }
  20. /**************************
  21. **** Sample usage ***/
  22. $arr = Array('Actionscript' => 35, 'Adobe' => 22, 'Array' => 44, 'Background' => 43,
  23. 'Blur' => 18, 'Canvas' => 33, 'Class' => 15, 'Color Palette' => 11, 'Crop' => 42,
  24. 'Delimiter' => 13, 'Depth' => 34, 'Design' => 8, 'Encode' => 12, 'Encryption' => 30,
  25. 'Extract' => 28, 'Filters' => 42);
  26. echo getCloud($arr, 12, 36);
13. PHP寻找两个字符串的相似性 PHP 提供了一个极少使用的 similar_text 函数,但此函数非常有用,用于比较两个字符串并返回相似程度的百分比。
  1. similar_text($string1, $string2, $percent);
  2. //$percent will have the percentage of similarity
14. PHP在应用程序中使用 Gravatar 通用头像 随着 WordPress 越来越普及,Gravatar 也随之流行。由于 Gravatar 提供了易于使用的 API,将其纳入应用程序也变得十分方便。
  1. /******************
  2. *@email - Email address to show gravatar for
  3. *@size - size of gravatar
  4. *@default - URL of default gravatar to use
  5. *@rating - rating of Gravatar(G, PG, R, X)
  6. */
  7. function show_gravatar($email, $size, $default, $rating)
  8. {
  9. echo '<img src="http://www.gravatar.com/avatar.php?gravatar_id='.md5($email).
  10. '&default='.$default.'&size='.$size.'&rating='.$rating.'" width="'.$size.'px"
  11. height="'.$size.'px" />';
  12. }
15. PHP在字符断点处截断文字 所谓断字 (word break),即一个单词可在转行时断开的地方。这一函数将在断字处截断字符串。
  1. // Original PHP code by Chirp Internet: www.chirp.com.au
  2. // Please acknowledge use of this code by including this header.
  3. function myTruncate($string, $limit, $break=".", $pad="...") {
  4. // return with no change if string is shorter than $limit
  5. if(strlen($string) <= $limit)
  6. return $string;
  7. // is $break present between $limit and the end of the string?
  8. if(false !== ($breakpoint = strpos($string, $break, $limit))) {
  9. if($breakpoint < strlen($string) - 1) {
  10. $string = substr($string, 0, $breakpoint) . $pad;
  11. }
  12. }
  13. return $string;
  14. }
  15. /***** Example ****/
  16. $short_string=myTruncate($long_string, 100, ' ');
16. PHP文件 Zip 压缩
  1. /* creates a compressed zip file */
  2. function create_zip($files = array(),$destination = '',$overwrite = false) {
  3. //if the zip file already exists and overwrite is false, return false
  4. if(file_exists($destination) && !$overwrite) { return false; }
  5. //vars
  6. $valid_files = array();
  7. //if files were passed in...
  8. if(is_array($files)) {
  9. //cycle through each file
  10. foreach($files as $file) {
  11. //make sure the file exists
  12. if(file_exists($file)) {
  13. $valid_files[] = $file;
  14. }
  15. }
  16. }
  17. //if we have good files...
  18. if(count($valid_files)) {
  19. //create the archive
  20. $zip = new ZipArchive();
  21. if($zip->open($destination,$overwrite ? ZIPARCHIVE::OVERWRITE : ZIPARCHIVE::CREATE) !== true) {
  22. return false;
  23. }
  24. //add the files
  25. foreach($valid_files as $file) {
  26. $zip->addFile($file,$file);
  27. }
  28. //debug
  29. //echo 'The zip archive contains ',$zip->numFiles,' files with a status of ',$zip->status;
  30. //close the zip -- done!
  31. $zip->close();
  32. //check to make sure the file exists
  33. return file_exists($destination);
  34. }
  35. else
  36. {
  37. return false;
  38. }
  39. }
  40. /***** Example Usage ***/
  41. $files=array('file1.jpg', 'file2.jpg', 'file3.gif');
  42. create_zip($files, 'myzipfile.zip', true);
17. PHP解压缩 Zip 文件
  1. /**********************
  2. *@file - path to zip file
  3. *@destination - destination directory for unzipped files
  4. */
  5. function unzip_file($file, $destination){
  6. // create object
  7. $zip = new ZipArchive() ;
  8. // open archive
  9. if ($zip->open($file) !== TRUE) {
  10. die (’Could not open archive’);
  11. }
  12. // extract contents to destination directory
  13. $zip->extractTo($destination);
  14. // close archive
  15. $zip->close();
  16. echo 'Archive extracted to directory';
  17. }
18. PHP为 URL 地址预设 http 字符串 有时需要接受一些表单中的网址输入,但用户很少添加 http:// 字段,此代码将为网址添加该字段。
  1. if (!preg_match("/^(http|ftp):/", $_POST['url'])) {
  2. $_POST['url'] = 'http://'.$_POST['url'];
  3. }
19. PHP将网址字符串转换成超级链接 该函数将 URL 和 E-mail 地址字符串转换为可点击的超级链接。
  1. function makeClickableLinks($text) {
  2. $text = eregi_replace('(((f|ht){1}tp://)[-a-zA-Z0-9@:%_+.~#?&//=]+)',
  3. '<a href="\1">\1</a>', $text);
  4. $text = eregi_replace('([[:space:]()[{}])(www.[-a-zA-Z0-9@:%_+.~#?&//=]+)',
  5. '\1<a href="http://\2">\2</a>', $text);
  6. $text = eregi_replace('([_.0-9a-z-]+@([0-9a-z][0-9a-z-]+.)+[a-z]{2,3})',
  7. '<a href="mailto:\1">\1</a>', $text);
  8. return $text;
  9. }
20. PHP调整图像尺寸 创建图像缩略图需要许多时间,此代码将有助于了解缩略图的逻辑。
  1. /**********************
  2. *@filename - path to the image
  3. *@tmpname - temporary path to thumbnail
  4. *@xmax - max width
  5. *@ymax - max height
  6. */
  7. function resize_image($filename, $tmpname, $xmax, $ymax)
  8. {
  9. $ext = explode(".", $filename);
  10. $ext = $ext[count($ext)-1];
  11. if($ext == "jpg" || $ext == "jpeg")
  12. $im = imagecreatefromjpeg($tmpname);
  13. elseif($ext == "png")
  14. $im = imagecreatefrompng($tmpname);
  15. elseif($ext == "gif")
  16. $im = imagecreatefromgif($tmpname);
  17. $x = imagesx($im);
  18. $y = imagesy($im);
  19. if($x <= $xmax && $y <= $ymax)
  20. return $im;
  21. if($x >= $y) {
  22. $newx = $xmax;
  23. $newy = $newx * $y / $x;
  24. }
  25. else {
  26. $newy = $ymax;
  27. $newx = $x / $y * $newy;
  28. }
  29. $im2 = imagecreatetruecolor($newx, $newy);
  30. imagecopyresized($im2, $im, 0, 0, 0, 0, floor($newx), floor($newy), $x, $y);
  31. return $im2;
  32. }
21. PHP检测 ajax 请求 大多数的 JavaScript 框架如 jquery,Mootools 等,在发出 Ajax 请求时,都会发送额外的 HTTP_X_REQUESTED_WITH 头部信息,头当他们一个ajax请求,因此你可以在服务器端侦测到 Ajax 请求。
  1. if(!emptyempty($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest'){
  2. //If AJAX Request Then
  3. }else{
  4. //something else
  5. }