ping ip address every Nth second to keep VPN connection alive

Sometimes 'ping myipadress -t' to keep vpn connection alive doesn't work. Below is Java way.

import java.io.IOException;
import java.net.InetAddress;
import java.net.UnknownHostException;
public class VPNKeepAlive {
   public final static int TIMEOUT = 3000;
   public final static String URL = "myipaddress"; //ip address or domain name
   public static void main(String[] args) {
      try {
         InetAddress inetAddress = InetAddress.getByName(URL);
         while(true) {
            if(inetAddress.isReachable(TIMEOUT)) {
               Thread.sleep(60000);
            }
         }
      } catch (UnknownHostException e) {
         System.err.println(e);
      } catch (IOException e) {
         System.err.println(e);
      } catch (InterruptedException e) {
         System.err.println(e);
      }
   }
}

PHP Y2K38 Bug :furthest date can be stored is on 19 January 2038 ?

$date = '2040-02-01';
$format = 'l d F Y H:i';
$mydate1 = strtotime($date);
echo date($format, $mydate1);

If you’re seeing a date in the late 60’s or early 70’s ,your php affected by Y2K38 Bug.

alternative solution:

Use DateTime class in PHP version 5.2.

$mydate2 = new DateTime($date);
$mydate2->format($format),

javascript : trim white space

// trim blank space at the string
function trim_string( string ) {
   return string.replace(/(^\s*)|(\s*$)/g, '');
}

// trim blank space at the beginning
function left_trim_string( string ) {
   return string.replace(/(^\s*)/g, '');
}

// trim blank space at the end
function right_trim_string( string ) {
   return string.replace(/(\s*$)/g, '');
} 

jquery find selected checkbox

this code will go thru for every checkbox that is checked.
example :

$("input[type=checkbox]:checked").each(function() {
//code here
});
//$("<element>[<attribute>=<value>]:<condition>")

Fast searching with jquery selector

If you wish to use any of the meta-characters (#;&,.+*~':"!^$[]()=>|/ ) as a literal part of a name, you must escape the character with two backslashes: \\. For example, if you have an an input with name="names[]", you can use the selector$("input[name=names\\[\\]]").

• Attribute Contains Selector [name*=value]

  Attribute

  Selects elements that have the specified attribute with a value containing the a given substring.

• Attribute Contains Word Selector [name~=value]

  Attribute

  Selects elements that have the specified attribute with a value containing a given word, delimited by spaces.

• Attribute Ends With Selector [name$=value]

  Attribute

  Selects elements that have the specified attribute with a value ending exactly with a given string.

• Attribute Equals Selector [name=value]

  Attribute

  Selects elements that have the specified attribute with a value exactly equal to a certain value.

• Attribute Not Equal Selector [name!=value]

  Attribute

  Select elements that either don't have the specified attribute, or do have the specified attribute but not with a certain value.

• Attribute Starts With Selector [name^=value]

  Attribute

  Selects elements that have the specified attribute with a value beginning exactly with a given string.

  
  

  full reference : http://api.jquery.com/category/selectors/

  jquery selector cheat sheet : http://www.skidoosh.co.uk/jquery/jquery-selectors-and-attribute-selectors-reference-and-examples-v2/