How to synchronize MySQL time with server time?

This command

SET GLOBAL time_zone = 'SYSTEM';

If you can edit my.cnf file, set MySQL default timezone with this line

[mysqld]

default-time-zone='SYSTEM'

How to save progressive JPEG with GD Library?

PHP imageinterlace() funtion turns the interlace bit on or off.

If the interlace bit is set and the image is used as a JPEG image, the image is created as a progressive JPEG.

<?php

// Create an image instance

$im = imagecreatefromjpeg('test.jpg');

// Enable interlancing

imageinterlace($im, true);

// Save the interlaced image

imagegif($im, './progressive.jpg');

imagedestroy($im);

?>

How to [recursively] Zip a directory in PHP?

You can Zip a directory with ZipArchive Class in PHP easily.


<?php
function archive($path, $archive, $pathcleaning = false){
$zip = new ZipArchive();
if ($zip->open($archive, ZIPARCHIVE::CREATE) !== TRUE) {  die ("Could not open archive");  }
$iterator = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($path));
foreach ($iterator as $key=>$value) 
if(basename($key) != '.' && basename($key) != '..'){
$zip->addFile(realpath($key), $pathcleaning ? str_replace($path, '', $key) : $key) or die ("ERROR: Could not add file: $key");
}
$zip->close();
}


// zip a directory
archive('data/', 'data.zip', true);


// get the zip file
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename="data.zip"');
header('Content-Transfer-Encoding: binary');
readfile('data.zip');
?>

How to create subdomains using htaccess?

First, you should set all subdomains to one directory in your web server config.

like this one below: 

ServerName  mydomain.com

ServerAlias   *.mydomain.com

Second, add this code to your .htacess file

RewriteEngine on
# SUB DOMAINS
RewriteCond %{http_host} !www\.([a-z0-9-]+)\.([a-z0-9-]{2,5})$ [NC]
RewriteCond %{http_host} ^(www.)?([a-z0-9-]+)\.([a-z0-9-]+)\.([a-z0-9-]{2,5})$ [NC]
RewriteRule (.*) /clients/%2/$1 [L]
# /SUB DOMAINS 

Finally, you should create a /clients/ folder in the main directory. Now every folder under /clients/ folder is a subdomain. 

For ex. If you have a test/ folder under the /clients/ folder, you can call the folder test.mydomain.com