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。
function getRealIpAddr() {
if (!emptyempty($_SERVER['HTTP_CLIENT_IP'])) {
$ip=$_SERVER['HTTP_CLIENT_IP'];
} elseif (!emptyempty($_SERVER['HTTP_X_FORWARDED_FOR'])) {
$ip=$_SERVER['HTTP_X_FORWARDED_FOR'];
} else {
$ip=$_SERVER['REMOTE_ADDR'];
}
return $ip;
}11. PHP强制性文件下载
为用户提供强制性的文件下载功能。
/******************** *@file - path to file */
function force_download($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创建标签云
function getCloud( $data = array(), $minFontSize = 12, $maxFontSize = 30 ) {
$minminimumCount = min( array_values( $data ) );
$maxmaximumCount = 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[] = '' . 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。
similar_text($string1, $string2, $percent); //$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。
/****************** *@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, $rating) {
echo '';
}15. PHP在字符断点处截断文字
所谓断字 (word break)，即一个单词可在转行时断开的地方。这一函数将在断字处截断字符串。
// Original PHP code by Chirp Internet: www.chirp.com.au
// Please acknowledge use of this code by including this header.
function myTruncate($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 压缩
/* 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解压缩 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。
if (!preg_match("/^(http|ftp):/", $_POST['url'])) {
$_POST['url'] = 'http://'.$_POST['url'];
}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。
function makeClickableLinks($text) {
$text = eregi_replace('(((f|ht){1}tp://)[-a-zA-Z0-9@:%_+.~#?&//=]+)', '\1a>',$text);
$text = eregi_replace('([[:space:]()[{}])(www.[-a-zA-Z0-9@:%_+.~#?&//=]+)', '\1\2a>', $text);
$text = eregi_replace('([_.0-9a-z-]+@([0-9a-z][0-9a-z-]+.)+[a-z]{2,3})', '\1a>', $text);
return $text;
}20. PHP调整图像尺寸
创建图像缩略图需要许多时间，此代码将有助于了解缩略图的逻辑。
/********************** *@filename - path to the image *@tmpname - temporary path to thumbnail *@xmax - max width *@ymax - max height */
function resize_image($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 $im2;
}
21. PHP检测 ajax 请求
大多数的 JavaScript 框架如 jquery，Mootools 等，在发出 Ajax 请求时，都会发送额外的 HTTP_X_REQUESTED_WITH 头部信息，头当他们一个ajax请求，因此你可以在服务器端侦测到 Ajax 请求。
if(!emptyempty($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest'){
//If AJAX Request Then
}else{
//something else
}