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Biography : Muhammad Zafar Iqbal

Mohammad Jafar Iqbal is a prominent writer in Bangladesh and of Bangla literature. He is basically a scientific writer what you can assume as a science fiction writer.

Mohammad Jafar Iqbal born on 23 December, 1952 in Sylhet. His father name is Fayzur Rahman who was a police officer. His mother name is Ayesha Foyez. His father was killed in 1971 during the liberation war of Bangladesh. Mohammad Jafar Iqbal has to traveled many areas of Bangladesh with his family in his early life because of types of his father's job.

Mohammad Iqbal has married Dr. Yasmeen Haque in 1978. This couple has two children a son named Nabil and a daughter named Yeshim.

Mohammad Jafar Iqbal has two brother who are also prominent in the Bangla literature. Humayun Ahmed is his elder brother who is the most prominent Bangla novelist in Bangladesh. Ahsan Habib is his younger brother who has written also some Bangla books and editor of Bangla magazine Unmad.

Mohammad Jafar Iqbal basically a science fiction novel writer. Without science fiction, he has written some novel with our regular field of life also. He is a powerful writer of Bangla literature.

Academic career of Mohammad Jafar Iqbal
SSC- Bogora Zila School in 1968
HSC- Dhaka College in 1970
Bsc in Physics- Dhaka University in 1976

Furthermore, Mohammad Jafar Iqbal has obtained his PhD from University of Washington in 1982.

Mohammad Jafar Iqbal has worked as a research scientist in Bell Communication Research from 1988 to 1994(for Six Year). After that he joined as a professor of department CSE and EEE Shahjalal University of Science and Technology.

Mohammad Jafar Iqbal, powerful writer of Bangla literature world, is continuing his writing without stopping.
Few Books of Muhammad Zafar Iqbal
Meyetir Naam Narina
Cromium Aronno
Hat Kata Robin
All Books of Muhammad Zafar Iqbal
Article and Tutorial
25 Acts of Email Cruelty: Do not be cruel in email--stop doing these things
By John Brandon


You arrive at work and the first message waiting at the top of your Gmail is rude, sarcastic, and demeaning. That's not exactly the intended use of the communication method.

Email is great for explaining a complex topic, documenting a subject, and communicating about upcoming plans. Using it to take your anger out on someone? That's just another way of being cruel.

These examples of being harsh by email won't help anyone stay productive and focused on their work, or enjoy being in the office:

1. Responding to an email with just a Web link without any explanation. I am guilty as charged. I recently realized it's a little gruff. It's better to at least give a quick annotation. (In some cases, it's obviously just a quick and helpful aid.)

2. Answering an email with one word and no other explanation. I'll contend it is sometimes the only way to cut people off, but you wouldn't do that in the grocery line, right? Right? One word replies sometimes work, sometimes they are just rude.

3. Using the word unfortunately. I have mentioned this one before. Unfortunately, people keep using it in emails and it still seems dismissive.

4. Swearing. I'm just not a fan of swearing in general--it's a bit lazy. And, you never know if someone will take your humor the wrong way. Or show the message to the boss.

5. Not answering at all. Somehow society in general decided "no reply" to an email is no answer. It's better to at least reply and give an explanation.

6. Pestering. The all-time record for someone asking me about their product is around six emails. It's okay to remind me. It's not okay to pummel.

7. Writing a lengthy email about why that person is an idiot. I understand people get angry and need to vent. My solution? Go ahead and write the long email, then delete it. Or just go talk to the person.

8. Boring people with too much detail. This is not a NASA rocket convention. By cleaning up your prose and summarizing things, you are making the recipient much happier in life.

9. Arguing over email. Arguments sometimes erupt over email, and it just causes people a lot of stress. Stick to the phone or, better yet, just let something slide once in a while.

10. Not calling. Sometimes, it's just cruel to email period. There are some topics, like trying to retain an employee or discussing future plans, that are best voice calls.

11. Blaming by email. It's an easy way to avoid confrontation, but a really terrible way of resolving anything. Blaming by email almost always puts some on the defense.

12. Being terse. Face it, we've all sent short and snappy emails. It's not always a bad thing. However, not explaining yourself fully usually creates a communication nightmare.

13. Criticizing grammar. Sure, your recipient has not mastered the difference betweeneffect and affect. I get that. Calling out bad grammar just slows down the discussion.

14. Explaining at length why it is better to do a phone call. I've received these missives before. Isn't it better to just call and explain that? Or just arranging the call without hammering the point?

15. Making fun of someone for hitting Reply All by mistake. Sure, it's a little dumb. It becomes cruel when everyone starts making fun of the original sender.

16. Making sexual overtones. You'd be surprised how often people send suggestive emails, making a permanent record of the debauchery that's easy to bring up in a performance review.

17. Forwarding spam. Really? I suppose there might be a small minority of spam messages that are funny or weird, but please keep them to yourself.

18. Sending chain mail. These are not just annoying, they usually don't make any sense. Plus, no one will ever know that you broke the chain--not even Stevie Nicks.

19. Letting everyone knowyou're the boss. Another tactic that just looks bad by email (or in any context). It's better to develop trust, respect, and even admiration from employees by making good decisions.

20. Belittling. Sure, the recipient screwed up a project and doesn't seem to understand basic business practices. Using email to chastise them just makes you look mean.

21. Telling lies. Watch yourself on this one. If you lie by email, the recipient can pretty easily prove you wrong--and they will hang onto the message as proof.

22. Sending an animate GIF. Apart from clogging up the email pathways, not everyone is amused by a dancing kitten. Plus, not every email program can read them.

23. Firing someone. Well, this one is obvious but it has happened. If you have to terminate someone, always do it in person and follow well-established guidelines.

24. Dramatically altering a project. I'm convinced people use email to make a sweeping change because they don't want to deal with the backlash. It's just not the best way to make big changes.

25. Closing down a business entirely. Has it finally come to the bitter end? Hold an all-hands meeting or talk to employees one-on-one. Don't use email for it.
Yeah, yeah, yeah. We know breakfast is the most important meal of the day. So we’ve been told by nearly every mother, gym teacher, and nutritionist since the beginning of time. But sometimes, it’s not that we don’t have time to scarf down a bowl of sugary breakfast cereal—we just don’t want to. Sweet breakfasts are not our thing.

If you’re the same way, here are some scrumptiously savory breakfasts…for folks who like life on the savory side.

Writing Secure PHP
Learn how to avoid some of the most common mistakes in PHP, and so make your sites more secure.

PHP is a very easy language to learn, and many people without any sort of background in programming learn it as a way to add interactivity to their web sites. Unfortunately, that often means PHP programmers, especially those newer to web development, are unaware of the potential security risks their web applications can contain. Here are a few of the more common security problems and how to avoid them.

Rule Number One: Never, Ever, Trust Your Users

It can never be said enough times, you should never, ever, ever trust your users to send you the data you expect. I have heard many people respond to that with something like "Oh, nobody malicious would be interested in my site". Leaving aside that that could not be more wrong, it is not always a malicious user who can exploit a security hole - problems can just as easily arise because of a user unintentionally doing something wrong.

So the cardinal rule of all web development, and I can't stress it enough, is: Never, Ever, Trust Your Users. Assume every single piece of data your site collects from a user contains malicious code. Always. That includes data you think you have checked with client-side validation, for example using JavaScript. If you can manage that, you'll be off to a good start. If PHP security is important to you, this single point is the most important to learn. Personally, I have a "PHP Security" sheet next to my desk with major points on, and this is in large bold text, right at the top.
Global Variables

In many languages you must explicitly create a variable in order to use it. In PHP, there is an option, "register_globals", that you can set in php.ini that allows you to use global variables, ones you do not need to explicitly create.

Consider the following code:

    if ($password == "my_password") {

    $authorized = 1;


    if ($authorized == 1) {

    echo "Lots of important stuff.";


To many that may look fine, and in fact this exact type of code is in use all over the web. However, if a server has "register_globals" set to on, then simply adding "?authorized=1" to the URL will give anyone free access to exactly what you do not want everyone to see. This is one of the most common PHP security problems.

Fortunately, this has a couple of possible simple solutions. The first, and perhaps the best, is to set "register_globals" to off. The second is to ensure that you only use variables that you have explicitly set yourself. In the above example, that would mean adding "$authorized = 0;" at the beginning of the script:

$authorized = 0;

if ($password == "my_password") {

    $authorized = 1;


if ($authorized == 1) {

    echo "Lots of important stuff.";


Error Messages

Errors are a very useful tool for both programmer and hacker. A developer needs them in order to fix bugs. A hacker can use them to find out all sorts of information about a site, from the directory structure of the server to database login information. If possible, it is best to turn off all error reporting in a live application. PHP can be told to do this through .htaccess or php.ini, by setting "error_reporting" to "0". If you have a development environment, you can set a different error reporting level for that.

SQL Injection

One of PHP's greatest strengths is the ease with which it can communicate with databases, most notably MySQL. Many people make extensive use of this, and a great many sites, including this one, rely on databases to function.

However, as you would expect, with that much power there are potentially huge security problems you can face. Fortunately, there are plenty of solutions. The most common security hazard faced when interacting with a database is that of SQL Injection - when a user uses a security glitch to run SQL queries on your database.

Let's use a common example. Many login systems feature a line that looks a lot like this when checking the username and password entered into a form by a user against a database of valid username and password combinations, for example to control access to an administration area:

$check = mysql_query("SELECT Username, Password, UserLevel FROM Users WHERE Username = '".$_POST['username']."' and Password = '".$_POST['password']."'");

Look familiar? It may well do. And on the face of it, the above does not look like it could do much damage. But let's say for a moment that I enter the following into the "username" input box in the form and submit it:

' OR 1=1 #

The query that is going to be executed will now look like this:

SELECT Username, Password FROM Users WHERE Username = '' OR 1=1 #' and Password = ''

The hash symbol (#) tells MySQL that everything following it is a comment and to ignore it. So it will actually only execute the SQL up to that point. As 1 always equals 1, the SQL will return all of the usernames and passwords from the database. And as the first username and password combination in most user login databases is the admin user, the person who simply entered a few symbols in a username box is now logged in as your website administrator, with the same powers they would have if they actually knew the username and password.

With a little creativity, the above can be exploited further, allowing a user to create their own login account, read credit card numbers or even wipe a database clean.

Fortunately, this type of vulnerability is easy enough to work around. By checking for apostrophes in the items we enter into the database, and removing or neutralising them, we can prevent anyone from running their own SQL code on our database. The function below would do the trick:

function make_safe($variable) {

    $variable = mysql_real_escape_string(trim($variable));

    return $variable;


Now, to modify our query. Instead of using _POST variables as in the query above, we now run all user data through the make_safe function, resulting in the following code:

$username = make_safe($_POST['username']);

$password = make_safe($_POST['password']);

$check = mysql_query("SELECT Username, Password, UserLevel FROM Users WHERE Username = '".$username."' and Password = '".$password."'");

Now, if a user entered the malicious data above, the query will look like the following, which is perfectly harmless. The following query will select from a database where the username is equal to "\' OR 1=1 #".

SELECT Username, Password, UserLevel FROM Users WHERE Username = '\' OR 1=1 #' and Password = ''

Now, unless you happen to have a user with a very unusual username and a blank password, your malicious attacker will not be able to do any damage at all. It is important to check all data passed to your database like this, however secure you think it is. HTTP Headers sent from the user can be faked. Their referral address can be faked. Their browsers User Agent string can be faked. Do not trust a single piece of data sent by the user, though, and you will be fine.

File Manipulation

Some sites currently running on the web today have URLs that look like this:


The "index.php" file then simply includes the "contactus.html" file, and the site appears to work. However, the user can very easily change the "contactus.html" bit to anything they like. For example, if you are using Apache's mod_auth to protect files and have saved your password in a file named ".htpasswd" (the conventional name), then if a user were to visit the following address, the script would output your username and password:


By changing the URL, on some systems, to reference a file on another server, they could even run PHP that they have written on your site. Scared? You should be. Fortunately, again, this is reasonably easy to protect against. First, make sure you have correctly set "open_basedir" in your php.ini file, and have set "allow_url_fopen" to "off". That will prevent most of these kinds of attacks by preventing the inclusion of remote files and system files. Next, if you can, check the file requested against a list of valid files. If you limit the files that can be accessed using this script, you will save yourself a lot of aggravation later.

Using Defaults

When MySQL is installed, it uses a default username of "root" and blank password. SQL Server uses "sa" as the default user with a blank password. If someone finds the address of your database server and wants to try to log in, these are the first combinations they will try. If you have not set a different password (and ideally username as well) than the default, then you may well wake up one morning to find your database has been wiped and all your customers' credit card numbers stolen. The same applies to all software you use - if software comes with default username or password, change them.

Leaving Installation Files Online

Many PHP programs come with installation files. Many of these are self-deleting once run, and many applications will refuse to run until you delete the installation files. Many however, will not pay the blindest bit of attention if the install files are still online. If they are still online, they may still be usable, and someone may be able to use them to overwrite your entire site.


Let us imagine for a second that your site has attracted the attention of a Bad Person. This Bad Person wants to break in to your administration area, and change all of your product descriptions to "This Product Sucks". I would hazard a guess that their first step will be to go to - just in case it exists. Placing your sensitive files and folders somewhere predictable like that makes life for potential hackers that little bit easier.

With this in mind, make sure you name your sensitive files and folders so that they are tough to guess. Placing your admin area at might make it harder to just type in quickly, but it adds an extra layer of security to your site. Pick something memorable by all means if you need an address you can remember quickly, but don't pick "admin" or "administration" (or your username or password). Pick something unusual.

The same applies to usernames and passwords. If you have an admin area, do not use "admin" as the username and "password" as the password. Pick something unusual, ideally with both letters and numbers (some hackers use something called a "dictionary attack", trying every word in a dictionary as a password until they find a word that works - adding a couple of digits to the end of a password renders this type of attack useless). It is also wise to change your password fairly regularly (every month or two).

Finally, make sure that your error messages give nothing away. If your admin area gives an error message saying "Unknown Username" when a bad username is entered and "Wrong Password" when the wrong password is entered, a malicious user will know when they've managed to guess a valid username. Using a generic "Login Error" error message for both of the above means that a malicious user will have no idea if it is the username or password he has entered that is wrong.

Finally, Be Completely and Utterly Paranoid

If you assume your site will never come under attack, or face any problems of any sort, then when something eventually does go wrong, you will be in massive amounts of trouble. If, on the other hand, you assume every single visitor to your site is out to get you and you are permanently at war, you will help yourself to keep your site secure, and be prepared in case things should go wrong.