PHP一些实用的自定义函数收集
2011-11-05 00:00
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虽然PHP自带的函数库很强大，但是在日常很多情况下，我们也还得自己写自定义的函数去实现某些功能与需求。下面收集了一些比较实用的、解决一些常见需求的自定义函数，比如将网址字符串转换成超级链接、列出目录内容、验证邮件地址等等，如果你觉得好，可以收藏本页，方便以后翻阅～
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。/**************
*@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 $password;
}2. PHP生成一个随机字符串
如果不需要可阅读的字符串，使用此函数替代，即可创建一个随机字符串，作为用户的随机密码等。/*************
*@l - length of random string
*/
function generate_rand($l){
$c= "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
srand((double)microtime()*1000000);
for($i=0; $i < $l; $i++) {
$rand.= $c[rand()%strlen($c)];
}
return $rand;
}3. PHP编码电子邮件地址
使用此代码，可以将任何电子邮件地址编码为 html 字符实体，以防止被垃圾邮件程序收集。function encode_email($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 = '<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 $encoded;
}4. PHP验证邮件地址
电子邮件验证也许是中最常用的网页表单验证，此代码除了验证电子邮件地址，也可以选择检查邮件域所属 DNS 中的 MX 记录，使邮件验证功能更加强大。function is_valid_email($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, $mxrecords);
}
else
return true;
else
return false;
}5. PHP列出目录内容
function list_files($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($handle);
}
}
}6. PHP销毁目录
删除一个目录，包括它的内容。/*****
*@dir - Directory to destroy
*@virtual[optional]- whether a virtual directory
*/
function destroyDir($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 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。$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 php8. PHP解析 XML 数据
//xml string
$xml_string="<?xml version='1.0'?>
<users>
<user id='398'>
<name>Foo</name>
<email>foo@bar.com</name>
</user>
<user id='867'>
<name>Foobar</name>
<email>foobar@foo.com</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 $user->email, '<br />';
}9. PHP创建日志缩略名
创建用户友好的日志缩略名。function create_slug($string){
$slug=preg_replace('/[^A-Za-z0-9-]+/', '-', $string);
return $slug;
}10. PHP获取客户端真实 IP 地址
该函数将获取用户的真实 IP 地址，即便他使用代理服务器。function getRealIpAddr()
{
if (!emptyempty($_SERVER['HTTP_CLIENT_IP']))
{
$ip=$_SERVER['HTTP_CLIENT_IP'];
}
elseif (!emptyempty($_SERVER['HTTP_X_FORWARDED_FOR']))
//to check ip is pass from proxy
{
$ip=$_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 )
{
$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, $rating)
{
echo '<img src="http://www.gravatar.com/avatar.php?gravatar_id='.md5($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@:%_+.~#?&//=]+)',
'<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($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest'){
//If AJAX Request Then
}else{
//something else22. 关键词高亮
function highlight($sString, $aWords) {
if (!is_array ($aWords) || emptyempty ($aWords) || !is_string ($sString)) {
return false;
}
$sWords = implode ('|', $aWords);
return preg_replace ('@\b('.$sWords.')\b@si', '<strong style="background-color:yellow">$1</strong>', $sString);
}23. 获取你的Feedburner的用户
function get_average_readers($feed_id,$interval = 7){
$today = date('Y-m-d', strtotime("now"));
$ago = date('Y-m-d', strtotime("-".$interval." days"));
$feed_url="https://feedburner.google.com/api/awareness/1.0/GetFeedData?uri=".$feed_id."&dates=".$ago.",".$today;
$ch = curl_init();
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_URL, $feed_url);
$data = curl_exec($ch);
curl_close($ch);
$xml = new SimpleXMLElement($data);
$fb = $xml->feed->entry['circulation'];
$nb = 0;
foreach($xml->feed->children() as $circ){
$nb += $circ['circulation'];
}
return round($nb/$interval);
}24. 自动生成密码
function generatePassword($length=9, $strength=0) {
$vowels = 'aeuy';
$consonants = 'bdghjmnpqrstvz';
if ($strength >= 1) {
$consonants .= 'BDGHJLMNPQRSTVWXZ';
}
if ($strength >= 2) {
$vowels .= "AEUY";
}
if ($strength >= 4) {
$consonants .= '23456789';
}
if ($strength >= 8 ) {
$vowels .= '@#$%';
}
$password = '';
$alt = time() % 2;
for ($i = 0; $i < $length; $i++) {
if ($alt == 1) {
$password .= $consonants[(rand() % strlen($consonants))];
$alt = 0;
} else {
$password .= $vowels[(rand() % strlen($vowels))];
$alt = 1;
}
}
return $password;
}25. 压缩多个CSS文件
header('Content-type: text/css');
ob_start("compress");
function compress($buffer) {
/* remove comments */
$buffer = preg_replace('!/\*[^*]*\*+([^/][^*]*\*+)*/!', '', $buffer);
/* remove tabs, spaces, newlines, etc. */
$buffer = str_replace(array("\r\n", "\r", "\n", "\t", ' ', ' ', ' '), '', $buffer);
return $buffer;
}
/* your css files */
include('master.css');
include('typography.css');
include('grid.css');
include('print.css');
include('handheld.css');
ob_end_flush();26. 获取短网址
function getTinyUrl($url) {
return file_get_contents("http://tinyurl.com/api-create.php?url=".$url);
}27. 根据生日计算年龄
function age($date){
$year_diff = '';
$time = strtotime($date);
if(FALSE === $time){
return '';
}
$date = date('Y-m-d', $time);
list($year,$month,$day) = explode("-",$date);
$year_diff = date("Y") – $year;
$month_diff = date("m") – $month;
$day_diff = date("d") – $day;
if ($day_diff < 0 || $month_diff < 0) $year_diff–;
return $year_diff;
}28. 计算执行时间
//Create a variable for start time $time_start = microtime(true); // Place your PHP/HTML/JavaScript/CSS/Etc. Here //Create a variable for end time $time_end = microtime(true); //Subtract the two times to get seconds $time = $time_end - $time_start; echo 'Script took '.$time.' seconds to execute';
29. PHP的维护模式
function maintenance($mode = FALSE){
if($mode){
if(basename($_SERVER['SCRIPT_FILENAME']) != 'maintenance.php'){
header("Location: http://example.com/maintenance.php");
exit;
}
}else{
if(basename($_SERVER['SCRIPT_FILENAME']) == 'maintenance.php'){
header("Location: http://example.com/");
exit;
}
}
}30. 阻止CSS样式被缓存
<link href="/stylesheet.css?<?php echo time(); ?>" rel="stylesheet" type="text/css" /&glt;
31. 为数字增加 st\nd\rd 等
function make_ranked($rank) {
$last = substr( $rank, -1 );
$seclast = substr( $rank, -2, -1 );
if( $last > 3 || $last == 0 ) $ext = 'th';
else if( $last == 3 ) $ext = 'rd';
else if( $last == 2 ) $ext = 'nd';
else $ext = 'st';
if( $last == 1 && $seclast == 1) $ext = 'th';
if( $last == 2 && $seclast == 1) $ext = 'th';
if( $last == 3 && $seclast == 1) $ext = 'th';
return $rank.$ext;
}
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