再來二十一段救命的PHP代碼_PHP教程

上段：http://www.BkJia.com/kf/201110/109143.html

1. PHP可閱讀隨機字串

此代碼將建立一個可閱讀的字串，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產生一個隨機字串

如果不需要可閱讀的字串，使用此函數替代，即可建立一個隨機字串，作為使用者的隨機密碼等。

/*************

*@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 字元實體，以防止被垃圾郵件程式收集。

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 = '

$part2 = 'ilto:';

$part3 = '" '. $attrs .' >';

$part4 = '';

$encoded = '';

return $encoded;

}

4. PHP驗證郵件地址 www.2cto.com

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 ''.$file.'
'."\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 資料

與大多數流行的Web 服務如twitter 通過開放API 來提供資料一樣，它總是能夠知道如何解析API 資料的各種傳送格式，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 資料

//xml string

$xml_string="

Foo

foo@bar.com

Foobar

foobar@foo.com

";

//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, '
';

} 9. PHP建立日誌縮減名

建立方便使用的日誌縮減名。

function create_slug($string){

$slug=preg_replace('/[^A-Za-z0-9-]+/', '-', $string);

return $slug;

} 10. PHP擷取用戶端真實IP 位址

該函數將擷取使用者的真實IP 位址，即便他使用Proxy 伺服器。

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強制性檔案下載

為使用者提供強制性的檔案下載功能。

/********************

*@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建立標籤雲

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[] = '

. '" href="#" title="\'' . $tag .

'\' returned a count of ' . $count . '">'

. htmlspecialchars( stripslashes( $tag ) ) . '';

}

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，用於比較兩個字串並返回相似程度的百分比。

similar_text($string1, $string2, $percent);

//$percent will have the percentage of similarity 14. PHP在應用程式中使用Gravatar 通用頭像

隨著WordPress 越來越普及，Gravatar 也隨之流行。由於Gravatar 提供了便於使用的API，將其納入應用程式也變得十分方便。

/******************

*@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 '

'&default='.$default.'&size='.$size.'&rating='.$rating.'" width="'.$size.'px"

height="'.$size.'px" />';

} 15. PHP在字元斷點處截斷文字

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串。

16. PHP檔案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 檔案

/**********************

*@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 字串

有時需要接受一些表單中的網址輸入，但使用者很少添加http:// 欄位，此代碼將為網址添加該欄位。

if (!preg_match("/^(http|ftp):/", $_POST['url'])) {

$_POST['url'] = 'http://'.$_POST['url'];

} 19. PHP將網址字串轉換成超級連結

該函數將URL 和E-mail 地址字串轉換為可點擊的超級連結。

function makeClickableLinks($text) {

$text = eregi_replace('(((f|ht){1}tp://)[-a-zA-Z0-9@:%_+.~#?&//=]+)',

'\1', $text);

$text = eregi_replace('([[:space:]()[{}])(www.[-a-zA-Z0-9@:%_+.~#?&//=]+)',

'\1\2', $text);

$text = eregi_replace('([_.0-9a-z-]+@([0-9a-z][0-9a-z-]+.)+[a-z]{2,3})',

'\1', $text);

return $text;

} 20. PHP調整映像尺寸

建立映像縮圖需要許多時間，此代碼將有助於瞭解縮圖的邏輯。

/**********************

*@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 架構如jquery，Mootools 等，在發出Ajax 請求時，都會發送額外的HTTP_X_REQUESTED_WITH 頭部資訊，頭當他們一個ajax請求，因此你可以在伺服器端偵測到Ajax 請求。

if(!emptyempty($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest'){

//If AJAX Request Then

}else{

//something else

}

摘自 周飛甫的部落格

http://www.bkjia.com/PHPjc/478555.htmlwww.bkjia.comtruehttp://www.bkjia.com/PHPjc/478555.htmlTechArticle上段：http://www.2cto.com/kf/201110/109143.html 1. PHP可閱讀隨機字串 此代碼將建立一個可閱讀的字串，使其更接近詞典中的單詞，實用且具有密...

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