Encryption with JavaScript

DIGEST

digest.js is a javascript library implementing cryptographic digest and HMAC algorithms.

digest.js is designed for modern web browsers and requires the W3C Typed Arrays support. digest.js has been successfully tested with these web browsers:

• Chrome 11
• Firefox 4
• Safari 5.1
• IE 10

Supported algorithms:

• digest
  • MD5
  • SHA-1
  • SHA-256
• Message Authentication Code (MAC)
  • HMAC/MD5
  • HMAC/SHA-1
  • HMAC/SHA-256
• Password-Based Key Derivation Function (PBKDF)
• PBKDF1/SHA1
• PBKDF1/MD5
• PBKDF2/HMAC/SHA1
• PBKDF2/HMAC/SHA-256

NODE

Transports

• TLS
• HTTP
• SSH
• XHR
• Sockets

Ciphers

• CIPHER
• AES
• DES
• RC2

PKI

• RSA
• RSA-KEM
• X.509
• PKCS#5
• PKCS#7
• PKCS#8
• PKCS#10
• PKCS#12
• ASN.1

Message Digests

• SHA1
• SHA256
• SHA384
• SHA512
• MD5
• HMAC

Utilities

• Prime
• PRNG
• Tasks
• Utilities
• Logging
• Debugging
• Flash Socket Policy Module

Proxy Coding: Take control with the Proxy

Provide a surrogate or placeholder for another object to control access to it.

If the programming model for your distributed technology of choice includes the concept of a proxy, you're being forced into distributed object semantics

DATE with BASH Shell

Was struggling to get date validated in linux ... writing a script with all that date parsing checks (valid day, month etc.) naah there mus be some easy way, something that is built in. The OS itself manages date and time so it should have the logic built in. Why not leverage it.

Came across this date command in shell, which is designed to handle relative date calculations and return/print them to you in a user defined way.

Everyone is familiar with the $ date command

cmd:   $ date
result:  Tue May 14 07:47:45 IST 2013 


Now getting the previous day
cmd:   $ date --date="yesterday"
result:  Tue May 13 07:50:35 IST 2013 



Now getting the next day

cmd:   $ date --date="next day"
result:  Tue May 15 07:50:55 IST 2013 

Looks  great isn't it and not only this one can use different string formats to get the same output
Example

cmd:   $ date --date="1 days ago"   or
cmd:   $ date --date="1 day ago"  or
cmd:   $ date --date="-1 day"    or
cmd:   $ date --date="yesterday"    
result:  Tue May 13 07:50:35 IST 2013

Example of various string formats is
Past:
cmd:   $ date --date="yesterday"
cmd:   $ date --date="20 minute ago"
cmd:   $ date --date="2 hour ago"
cmd:   $ date --date="last Friday"
cmd:   $ date --date="10 days ago"
cmd:   $ date --date="10 week ago"
cmd:   $ date --date="10 month ago"

Future:
cmd:   $ date --date="tommorrow"
cmd:   $ date --date="20 minute"
cmd:   $ date --date="2 hour"
cmd:   $ date --date="this Friday"
cmd:   $ date --date="10 days "
cmd:   $ date --date="10 week"
cmd:   $ date --date="10 month "

Its amazing... very nicely coded and not only this you can specify your custom date format

cmd:   $ date --date="tommorrow" + "%d/%m/%Y"

Hope you find it interesting and helpful too..

Have a nice time playing with your dates. -S

UPDATE .. FROM syntax difference in Sql Server and Oracle

There is syntactical difference in few operations in SQL in Oracel and Sql server

For example: UPDATE .. FROM

UPDATE students

     SET grade='A'

FROM students s 

INNER JOIN students_marks sm ON sm.student_id = s.student_id

WHERE sm.total_marks>80;

The above query syntax works in Sql Server but will fail in Oracle.

Below is the Oracle alternative.

UPDATE 

     (SELECT grade 

             FROM students s

             INNER JOIN students_marks sm ON sm.student_id = s.student_id

             WHERE sm.total_marks>80) t 

SET t.grade='A';

Below is the block diagram for the Oracle query

Find when a DB Object was created in ORACLE

I came across a requirement where I need to find when a table on the schema was modified. I am posting the solution here so as my other fellow programmers can get the idea.

SELECT * FROM  all_objects
WHERE  owner = 'object_owner'
AND object_name = 'object_name'

The column "CREATED" tells you when the object was created. The column "LAST_DDL_TIME" tells you when the last DDL was performed against the object.

Example:

SELECT created
FROM all_objects
WHERE object_name = 'my_table'
AND owner = 'sysdba'
AND object_type = 'TABLE'

It will tell you when a table was created.

The odds are good, but the goods are odd. -S

Awesome Java NIO

Easy File Reading

public static List getNamesFromFile(String filetoread)
{
 List lines = null;    
 try
 {
  lines = Files.readAllLines(Paths.get(filetoread), Charset.forName("UTF-8"));
 }
 catch(Exception e)
 {
  System.out.println("Error reading list file \n " + e);     
 }

 return lines;
} // end getNames



Easy File Copy

public static void copyFile(File src, File dest) throws IOException
{
 if (!src.exists())
 {
  // either return quietly OR throw an exception
  return;
 }

 if (!dest.exists())
 {
  dest.createNewFile();
 }

 try
 {
  FileChannel source = new FileInputStream(src).getChannel();
  FileChannel destination = new FileOutputStream(dest).getChannel();

  try
  {
   source.transferTo(0, source.size(), destination);
   // destination.transferFrom(source, 0, source.size());
  }
  finally
  {
   if (destination != null)
   {
    destination.close();
   }
  }
 }
 finally
 {
  if (source != null)
  {
   source.close();
  }
 }

} // function ends
 

Neo here is new NIO. -S

CSS ... Selectors to be learned

Selector	Example	Example description	Since CSS version	Supported in
.class	.intro	Selects all elements with class="intro"	1	IE6+ Firefox Chrome Safari Opera
#id	#firstname	Selects the element with id="firstname"	1	IE6+ Firefox Chrome Safari Opera
*	*	Selects all elements	2	IE6+ Firefox Chrome Safari Opera
element	p	Selects all elements	1	IE6+ Firefox Chrome Safari Opera
element,element	div,p	Selects all elements and all elements	1	IE6+ Firefox Chrome Safari Opera
element element	div p	Selects all elements inside elements	1	IE6+ Firefox Chrome Safari Opera
element>element	div>p	Selects all elements where the parent is a element	2	IE6+ Firefox Chrome Safari Opera
element+element	div+p	Selects all elements that are placed immediately after elements	2	IE6+ Firefox Chrome Safari Opera
[attribute]	[target]	Selects all elements with a target attribute	2	IE6+ Firefox Chrome Safari Opera
[attribute=value]	[target=_blank]	Selects all elements with target="_blank"	2	IE6+ Firefox Chrome Safari Opera
[attribute~=value]	[title~=flower]	Selects all elements with a title attribute containing the word "flower"	2	IE6+ Firefox Chrome Safari Opera
[attribute|=value]	[lang|=en]	Selects all elements with a lang attribute value starting with "en"	2	IE6+ Firefox Chrome Safari Opera
:link	a:link	Selects all unvisited links	1	IE6+ Firefox Chrome Safari Opera
:visited	a:visited	Selects all visited links	1	IE6+ Firefox Chrome Safari Opera
:active	a:active	Selects the active link	1	IE6+ Firefox Chrome Safari Opera
:hover	a:hover	Selects links on mouse over	1	IE7+ Firefox Chrome Safari Opera
:focus	input:focus	Selects the input element which has focus	2	IE8+ Firefox Chrome Safari Opera
:first-letter	p:first-letter	Selects the first letter of every element	1	IE8+ Firefox Chrome Safari Opera
:first-line	p:first-line	Selects the first line of every element	1	IE8+ Firefox Chrome Safari Opera
:first-child	p:first-child	Selects every element that is the first child of its parent	2	IE8+ Firefox Chrome Safari Opera
:before	p:before	Insert content before the content of every element	2	IE7+ Firefox Chrome Safari Opera
:after	p:after	Insert content after every element	2	IE7+ Firefox Chrome Safari Opera
:lang(language)	p:lang(it)	Selects every element with a lang attribute value starting with "it"	2	IE8+ Firefox Chrome Safari Opera
element1~element2	p~ul	Selects every element that are preceded by a element	3	IE8+ Firefox Chrome Safari Opera
[attribute^=value]	a[src^="https"]	Selects every element whose src attribute value begins with "https"	3	IE8+ Firefox Chrome Safari Opera
[attribute$=value]	a[src$=".pdf"]	Selects every element whose src attribute value ends with ".pdf"	3	IE8+ Firefox Chrome Safari Opera
[attribute*=value]	a[src*="coffee"]	Selects every element whose src attribute value contains the substring "coffee"	3	IE8+ Firefox Chrome Safari Opera
:first-of-type	p:first-of-type	Selects every element that is the first element of its parent	3	IE8+ Firefox Chrome Safari Opera
:last-of-type	p:last-of-type	Selects every element that is the last element of its parent	3	IE8+ Firefox Chrome Safari Opera
:only-of-type	p:only-of-type	Selects every element that is the only element of its parent	3	IE8+ Firefox Chrome Safari Opera
:only-child	p:only-child	Selects every element that is the only child of its parent	3	IE8+ Firefox Chrome Safari Opera
:nth-child(n)	p:nth-child(2)	Selects every element that is the second child of its parent	3	IE8+ Firefox Chrome Safari Opera
:nth-last-child(n)	p:nth-last-child(2)	Selects every element that is the second child of its parent, counting from the last child	3	IE8+ Firefox Chrome Safari Opera
:nth-of-type(n)	p:nth-of-type(2)	Selects every element that is the second element of its parent	3	IE8+ Firefox Chrome Safari Opera
:nth-last-of-type(n)	p:nth-last-of-type(2)	Selects every element that is the second element of its parent, counting from the last child	3	IE8+ Firefox Chrome Safari Opera
:last-child	p:last-child	Selects every element that is the last child of its parent	3	IE8+ Firefox Chrome Safari Opera
:root	:root	Selects the document’s root element	3	IE9+ Firefox Chrome Safari Opera
:empty	p:empty	Selects every element that has no children (including text nodes)	3	IE9+ Firefox3+ Chrome Safari Opera
:target	#news:target	Selects the current active #news element (clicked on a URL containing that anchor name)	3	IE8+ Firefox Chrome Safari Opera
:enabled	input:enabled	Selects every enabled input element	3	IE9+ Firefox3+ Chrome Safari Opera
:disabled	input:disabled	Selects every disabled input element	3	IE9+ Firefox3+ Chrome Safari Opera
:checked	input:checked	Selects every checked input element	3	IE9+ Firefox3+ Chrome Safari Opera
:not(selector)	:not(p)	Selects every element that is not a element	3	IE9+ Firefox Chrome Safari Opera
::selection	::selection	Selects the portion of an element that is selected by a user	3	IE6+ Firefox Chrome Safari Opera

Selecting the selectors. -S