給大家分享21個常用的PHP函數代碼段，內容如下：
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=’[email protected]’, $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”:”[email protected]”,”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>[email protected]</name>
</user>
<user id=’867′>
<name>Foobar</name>
<email>[email protected]</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[] = ‘<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，用於比較兩個字符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在應用程序中使用 Gravatar 通用頭像
隨著 WordPress 越來越普及，Gravatar 也隨之流行。由於 Gravatar 提供了易於使用的 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 $text;
}
20. PHP調整圖像尺寸
創建圖像縮略圖需要許多時間，此代碼將有助於了解縮略圖的邏輯。
/**********************
*@filename – path to the image
*@tmpname – temporary path to thumbnail
*@xmax – max width
*@ymax – max height
*/
function resize_image($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 $im2;
}
21. PHP檢測 ajax 請求
大多數的 JavaScript 框架如 jquery，Mootools 等，在發出 Ajax 請求時，都會發送額外的 HTTP_X_REQUESTED_WITH 頭部信息，頭當他們一個ajax請求，因此你可以在服務器端偵測到 AJax 請求。
if(!emptyempty($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == ‘XMLhttprequest’){
//If AJax Request Then
}else{
//something else
}
