Twenty Examples of Practical PHP Codes_PHP Tutorial

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 you do not need a readable string, use this function instead to create a random string as the user's random password, 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

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 of the email domain, 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. List directory contents with PHP

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 destroy directory

Deletes a directory, including its contents.

/*****
*@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 parsing JSON data

Like most popular web services such as twitter that provide data through open APIs, it always knows how to parse various delivery formats of API data, including JSON, XML, etc.

$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 parses XML data

//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 creates log abbreviation

Create user-friendly log abbreviations.

function create_slug($string){
$slug=preg_replace('/[^A-Za-z0-9-]+/', '-', $string);
return $slug;
}

10. PHP gets the real IP address of the client

This function will get the real IP address of the user, even if he uses a proxy server.

function getRealIpAddr()
{
If (!emptyempty(Twenty-one examples of practical PHP code - Webmaster Academy SERVER['REMOTE_ADDR'];
}
Return $ip;
}

11. PHP mandatory file download

Provide users with mandatory file download functionality.

/********************
*@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. Create tag cloud with PHP

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. Find similarity between two strings in PHP

PHP provides a rarely used similar_text function, but this function is very useful for comparing two strings and returning the percentage of similarity.

similar_text($string1, $string2, $percent);
//$percent will have the percentage of similarity

14. PHP uses Gravatar universal avatar in applications

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

/******************
*@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 truncates text at character breakpoints

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

// 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 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):/", 实用PHP代码二十一个实例 - 站长学院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@:%_+.~#?&//=]+)', '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;
}

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