Configure Amazon EC2

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1.Boot 2 linux servers on EC2
2.Assign elastic IP to each of them
3.Register a domain (eg
4.On the domain settings – create 2 host records – and and point each record to each of the elastic IPs.
5.On your 2 nameserver instances – create dns zone for ns1. and ns2 respectively
6.Make ns2 a slave of ns1 – you can if you wish add ns3… ns4.. etc etc but its not necessary unless your site is getting millions of users.
7.Boot another EC instance and install the Scalr application.
8.Create a user on ns1. called “named” that has permissions to update the dns zone records on ns1.
9.The DNS settings of the scalr application will refer to the nameservers ns1. with user “named” and password as set on ns1.
10.Your application for example will have the domain  Register this domain and set its nameservers to your ns1. and ns2 mentioned previously.
11.You need to first create a new zone file on ns1 for
12.In Scalr when asked for the application domain name – simply enter – and scalr will handle the rest.


You will need to register a domain name with a domain registrar.  After registering, you will need to enter your NS records for the domain name.  The NS records should point to a Domain Name Server (DNS).  Most registrars require at least two DNS servers to eliminate a single point of failure.

Some registrars provide free DNS services.  If you choose such a registrar, you would need to add a CNAME record for your sub-domain and ask any DNS application support related questions to your registrar.

Alternatively, you can launch and configure your own DNS servers on Amazon EC2.  A popular choice for Linux based DNS servers is BIND:

Another option is to outsource your DNS servers using a third-party provider, for example


Mysql useful queries

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Select DATE_FORMAT (NOW(), ‘%Y’) – DATE_FORMAT(BirthDate, ‘%Y’) – (DATE_FORMAT(NOW(), ’00-%m-%d’) < DATE_FORMAT(BirthDate, ’00-%m-%d’)) AS Age From tbl_member where 1;

Change collation:

Alter table `tbl_student` convert to character set utf8 collate utf8_swedish_ci;

Shift mysql column:

ALTER TABLE tableName MODIFY column column_2 int AFTER column_1;

Get video info with user info:
SELECT `video_id` , `video_title` ,
( SELECT userid FROM tbl_members
WHERE `member_id` = v.member_id
) AS owner
FROM `tbl_video` AS v

Select concat(a.Day,’_’,a.Hour) as IDX From tbl_time;

Switch Case:
SELECT, a.group_name ,
WHEN a.is_feature= ‘t’ THEN ‘Featured’
ELSE ‘Unfeatured’
END as Featured
FROM `tbl_member_groups` a;

2 Way Friendship:
SELECT CASE WHEN mf.member_id = ‘”78″
THEN mf.friend_id
ELSE mf.member_id
END AS f_id,
FROM tbl_member
WHERE mid = f_id
) AS uname
FROM tbl_member_friend AS mfWHERE ( member_id = ’78’ OR friend_id = ’78’ ) AND is_accepted = ‘t’;

SELECT b.ID as us_id,c.ID as ctu,c.Nationality,e.Name as cname, b.Username, d.Name FROM user b
LEFT JOIN teacher c ON b.ID = c.UserID
LEFT JOIN teacher_photo d ON c.ID = d.TeacherID
LEFT JOIN country e on e.ID=c.Nationality
IN ( SELECT CASE WHEN tf.user_id = ‘$ID’
THEN tf.friend_id
ELSE tf.user_id
END AS f_id
FROM friend tf
user_id = ‘$ID’
OR friend_id = ‘$ID’
AND tf.`is_accept` = ‘t’ order by tf.date_added desc

SELECT a. * , c.Nationality, e.Name AS cname, b.Username, d.Name
FROM forum_reply a
LEFT JOIN user b ON a.poster_thread_id = b.ID
LEFT JOIN teacher c ON a.poster_thread_id = c.UserID
AND b.ID = c.UserID
LEFT JOIN teacher_photo d ON c.ID = d.TeacherID
LEFT JOIN country e ON e.ID = c.Nationality
WHERE a.thread_id = ‘1’;

Remove duplicate records:
SELECT * FROM old_table WHERE 1 GROUP BY [COLUMN TO remove duplicates BY];

Stored Porcedures:
CREATE PROCEDURE simpleproc (OUT param1 INT)
SELECT * FROM testimonial;
CALL simpleproc(@a);

SQL Injection:
Select * from tbl_user where name = ‘sandeep’ OR ‘1’ = ‘1’;

Insert Duplicate:
INSERT INTO `teacher_photo` SET TeacherID =7, Name = ‘7-teacher.jpeg’,
FileType = ‘image/jpeg’ ON DUPLICATE KEY UPDATE Name = ‘7-teacher.jpeg’, FileType = ‘image/jpeg’;

Reporting month year wise:
Select count(hits), month(add_date) m, year(add_date) y From ‘sales’ where 1 group by m,y;

Interchange columns values:
Update userinfo set sex = case
when sex = ‘f’ then m
when sex = ‘m’ then f

Case sensitive data:
Select * From member where BINARY uname = “sandeep”;

Get third max mark holder:
Select * From ‘marks’ where 1 order by mark desc limit 2,1;

Get duplicate in table:
Select title From ‘books’ group by title having count(*) > 1;

Set Character set to UTF-8:
SET NAMES ‘utf8’;

Check for Online:
FROM tbl_member_groups

Form’s array element in javascript

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How to access form’s array element in javascript?

Web Post
Mobile Post
Application Post
Open Source Post


<form action=”<?=$_SERVER[‘PHP_SELF’]?>” method=”post”>

<input name=”post[]” type=”checkbox” value=”web” /> Web Post
<input name=”post[]” type=”checkbox” value=”mobile” /> Mobile Post
<input name=”post[]” type=”checkbox” value=”application” />Application Post
<input name=”post[]” type=”checkbox” value=”open” /> Open Source Post


<script type=”text/javascript”>

if([i].type==”checkbox” &&[i].name==”post[]”)




HTML WYSIWYG Editor for Fedora

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Quanta Plus is a web development tool for the K Desktop Environment. Quanta is designed for quick web development and is rapidly becoming a mature editor with a number of great features and lies at the heart of the KDE Web Dev suite of tools.

Bluefish is a powerful editor targeted towards programmers and webdesigners, with many options to write websites, scripts and programming code. Bluefish supports many programming and markup languages, and it focuses on editing dynamic and interactive websites.

Run C program in Linux

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This is the simple C file “svnlabs.c” to execute on linux terminal


int main()
int i;

printf(”n%d %s”,i,””);

return 0;


[root@localhost ~]# gcc svnlabs.c
[root@localhost ~]# make svnlabs
cc svnlabs.c -o svnlabs
[root@localhost ~]# ./svnlabs

[root@localhost ~]#

Run Java program in Linux

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This is the sample java file “” to be executed on linux command line…..

import java.lang.*;

public class Svnlabs

public static void main(String args[])



[root@localhost ~]# javac
[root@localhost ~]# java Svnlabs
[root@localhost ~]#

wine – run Windows programs on Linux

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wine – run Windows programs on Linux/Unix

wine program.exe [arguments …]
wine –help
wine –version

wine loads and runs the given program, where the program is a DOS, Win-       dows 3.x, or Win32 executable (x86 binaries only).

This will display all the output in a  separate  win-dows (this requires X11 to run).

Install wine on linux (RedHat, Fedora, CentOS…)

# yum install wine

# man wine


# wine /opt/test.exe


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Xmanager is a powerful and easy-to-use PC X server that runs on Windows platforms. It allows you to bring remote Unix/Linux desktops to your Windows PC seamlessly. You can also run remote X applications securely through the SSH (Secure Shell) protocol even when your Windows PC is inside a private network and a firewall is between your PC and the remote server.

Xmanager is used in various fields of work including large-scale craft and semiconductor designing and server management in an IDC (Internet Data Center). It is widely used by server administrators of universities and corporations, and personal users who simply want to connect to remote hosts over the internet. Xmanager is an easy and powerful PC X server designed to satisfy the needs and wants of these various users.


Lab Tips

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1. Delete all information from databse related to, if deleting user or any content from CMS.
2. Use PDO, ADO, Pear, Zend etc. library to connect to database.
3. Take regular backup for database.
4. Use better naming convension.

1. Use better naming convension.
2. Take regular backup for folders.
3. Protect project’s folder to unauthorized access, just put index.html or use apache security.
4. Folder name are case sensitive on servers like linux.
5. Don’t use 0777 permission on any folder use 0755.

1. Use better naming convension.
2. Use better documentation for web files, apply comments for coding and indent it.
3. Make consistency in DB, Filesnames, Variables, Page design.
4. Take regular backup for files.
5. Use caching for file to make site speed more fast.
6. Create debug files .txt, .log, .html etc. (fopen() | fwrite()) for tracking logical bugs.

1. Use version number in image URL to avoid image caching.
(<img src=”san.jpg?ver=123″ alt=”san” />)
2. Images should have Etags, Max Age and far future expired header for caching.
3. Use a global funtion to display images ( draw_images($src, $attr); )

1. Use better naming convension.
2. Use encryption class (md5, sha, base64 etc. with salt) for storing password and important data into database.
3. Spidering web page (Curl, Pear etc.) is used for getting content of web page.

1. Use function or include files for multiple use of web data to make reusability, integrity and productivity.
2. Use PHP session ID, remote IP and page name on increment views/hits.
3. Make function to load CSS, JS, Links, Forms & Elements, Images, Iframes etc. on webpage. (load_css_file(), load_js_file()….)
4. Looping should be start from Left to Right…

1. Use better naming convension.
2. Use defined variables/constants for folder names, DB table names, Files and global variables (avoid hard coding, be happy coder).

1. Avoid inline CSS on pages because it effect the page load time & speed also it matter in W3C validation.
2. Combine multiple CSS file in a single file with cached version.
3. Avoid conflict in CSS.
4. Avoid CSS expressions.
5. Use CSS Sprite for images.

1. Avoid inline JS on pages because it effect the page load time & speed also it matter in W3C validation.
2. Combine multiple JS file in a single file with cached version.
3. Use valid syntax for browser checking in javascript.
4. Avoid duplicate JS function.

1. Minimize the errors in HTML closing tags etc.
2. Use proper hyrarchy for HTML tags.
3. Use Math.random() in Ajax URL as parameter.
4. Send URL as parameter after encodeURIComponent() similar to urlencode() in PHP.
5. Use file_get_contents($url) for first time filling Ajax DIV.
6. Use new window to display javascript alert debug messages as append messages in log files.
7. Use Ajax Cached version.

1. On login page username/password should be case sensitive.
2. Open terms of use page in popup window on registration page.
3. Use better UI for Errors/Success messages.
4. Use cancle button near submit button.
5. Use captcha code on pages by session value to avoid Spams.
6. Put valid ALT values in IMG tags.
7. Use Enter button event on form’s submit control.
8. Use scrolling DIV on webpages for better GUI.
9. Use returnto parameter for redirecting page after login.
10. Use remember option on login page.
11. Use valid/correct statements in error/success/warning messages.
12. Use dynamic Title and Meta tags on page.
13. Use error pages like 404, 500 etc. by .htaccess
14. Use good NO/Blank image for image not found.
15. Use htmlspecialchars() in strings displayed on webpages for W3C validations.
16. Use favicon for webpages for better GUI.

1. Use good words like Dear, Regards, Thanks etc. in emails.
2. Attach some links, images, videos etc. for proper understanding.
3. Use reference and ref. # in emails.

1. Use IDE like APTANA, Dreamweaver, Zend Editor.
2. Use DW’s context menu for HTML/PHP code to avoid W3C errors/warnings.
3. Use FireFox plugins for development (Web Developer, Firebug, Scribefire, ColorZilla, FireFTP, S3Fire, ElastoFox, Gtalk, GrabScreen, YSlow, FireShot etc.) for site’s speed, performance and optimization.
4. Make sure we are using secure FTP, Email Client….
5. Command Line tools (putty, CMD etc.) are very good utilities for batch processes and large files.

1. View source and display function (echo, print etc.) are very useful for finding bugs and faults.
2. Try to search visual concept like jQuery, Ajax etc. on google images search engine.
3. Use google operator for getting better results.

Keep browsing, happy coding…………