21个实用PHP代码

 

21个实用PHP代码
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(‘@’, ‘&#64;’, $email);
$email = str_replace(‘.’, ‘&#46;’, $email);
$email = str_split($email, 5);
$linkText = str_replace(‘@’, ‘&#64;’, $linkText);
$linkText = str_replace(‘.’, ‘&#46;’, $linkText);
$linkText = str_split($linkText, 5);
$part1 = ‘<a href=”ma’;
$part2 = ‘ilto&#58;’;
$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 php
8. 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 else
}

来源:http://www.kunshanren.com/2011/03/14/php.html  昆山人网视

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已有 9 条评论
  1. 晨曦

    好东西

    晨曦 回复
  2. Cheap Jordans

    You actually make it seem so easy with your presentation but I find this matter to be actually something that I think I would never understand. It seems too complicated and very broad for me. I'm looking forward for your next post, I抣l try to get the hang of it!

    Cheap Jordans 回复
  3. 电伤圈

    曾学到的皮毛现在也忘了!

    电伤圈 回复
    1. 枫叶红秋雨

      @电伤圈

      @电伤圈 呵呵。没事温习下

      枫叶红秋雨 回复
  4. 減肥

    好文章,收藏

    減肥 回复
  5. 维生素E胶囊

    博文还是一样的好,谢谢你的分享,以后我会常来的。{smile:11}

    维生素E胶囊 回复
  6. 燕窝

    不错·我也要收藏起来

    燕窝 回复
  7. sprityaoyao

    嗯,这个好,先收藏了,以后用得上{smile:3}

    sprityaoyao 回复
    1. 枫叶红秋雨

      @sprityaoyao

      @sprityaoyao
      嗯,备用

      枫叶红秋雨 回复
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