Here are twenty-one life-saving PHP codes_PHP tutorial

Previous paragraph: http://www.BkJia.com/kf/201110/109143.html

1. PHP can read random strings

This code will create a readable string that is closer to the word in the dictionary, practical, and has password verification capabilities.

/**************

*@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 generates a random string

If a readable string is not required, use this function instead to create a random string that can be used as a random password for the user, etc.

/*************

*@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 encoded email address

Using this code, any email address can be encoded as an html character entity to prevent collection by spam programs.

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 = '';

$part4 = '';

$encoded = '';

Return $encoded;

}

4. PHP verification email address www.2cto.com

Email verification is perhaps the most commonly used web form verification in China. In addition to verifying the email address, this code can also choose to check the MX record in the DNS to which the email domain belongs, making the email verification function more powerful.

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 ''.$file.'
'."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="

Foo

foo@bar.com

Foobar

foobar@foo.com

"; 

 

//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, '
';

} 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[] = ''

. htmlspecialchars( stripslashes( $tag ) ) . '';

} 

 

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

As WordPress becomes more popular, so does Gravatar. Since Gravatar provides an easy-to-use API, it is easy to incorporate it into your application.

/******************

*@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 '

height="'.$size.'px" />';

} 15. PHP truncate text at character breakpoint

The so-called word break is the place where a word can be broken when changing lines. This function will truncate the string at hyphenation points.

16. PHP file Zip compression

/* 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 decompress Zip file

/**********************

*@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 defaults http string for URL address

Sometimes it is necessary to accept URL input in some forms, but users rarely add the http:// field, this code will add that field to the URL.

if (!preg_match("/^(http|ftp):/", $_POST['url'])) {

$_POST['url'] = 'http://'.$_POST['url'];

} 19. PHP converts URL string into hyperlink

This function converts URL and email address strings into clickable hyperlinks.

function makeClickableLinks($text) {

$text = eregi_replace('(((f|ht){1}tp://)[-a-zA-Z0-9@:%_+.~#?&//=]+)',

'1', $text);

$text = eregi_replace('([[:space:]()[{}])(www.[-a-zA-Z0-9@:%_+.~#?&//=]+)',

'12', $text);

$text = eregi_replace('([_.0-9a-z-]+@([0-9a-z][0-9a-z-]+.)+[a-z]{2,3})',

'1', $text);

return $text;

} 20. PHP resize image

Creating image thumbnails takes a lot of time, this code will help to understand the logic of thumbnails.

/**********************

*@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

}

 

摘自 周飞甫的博客

http://www.bkjia.com/PHPjc/478555.htmlwww.bkjia.comtruehttp://www.bkjia.com/PHPjc/478555.htmlTechArticle上段：http://www.2cto.com/kf/201110/109143.html 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...