下面介紹的是,在PHP 開發中,經常用到的21個函數代碼段,當我們用到的時候,就可以直接用了。
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,作爲用戶的隨機密碼等。
/*************
*@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爲 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銷燬目錄
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創建日誌縮略名
創建用戶友好的日誌縮略名。
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'];
}
//to check ip is pass from proxy
elseif (!emptyempty($_SERVER['HTTP_X_FORWARDED_FOR'])) {
$ip=$_SERVER[ 'HTTP_X_FORWARDED_FOR' ];
}
else {
$ip=$_SERVER[ 'REMOTE_ADDR' ];
}
return $ip;
}
11. PHP強制性文件下載
爲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 ;
$cloudTags[]='<a style="font-size:'.floor($size).'px'.' "href="#" title="\".$tag.'\' returned a count of '.$count.'">'. htmlspecialchars(stripslashes
($tag)).'</a>';
}
return join("\n",$cloudTags)."\n";
}
/**************************
**** Sample usage ***/
$arr=Array('Actionscrip'=> 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
隨着 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
$zip ->close();
echo 'Archive extracted to directory';
}
18. PHP爲 URL 地址預設 http 字符串
有時需要接受一些表單中的網址輸入,但用戶很少添加 http:// 字段,此代碼將爲網址添加該字段。
if(!preg_match("/^(http|ftp):/",$_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 地址字符串轉換爲可點擊的超級鏈接。
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,此代碼將有助於瞭解縮略圖的邏輯。
/**********************
*@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
}
到這,21個經常用到的PHP函數代碼段,就大家介紹完了。希望對你有幫助。
分享經常用到的21個PHP函數代碼段
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