Astuces

PHP Tutorial

2013-08-19T13:55:00.003-07:00

Introduction

Up until recently, scripting on the internet was something which very few people even attempted, let alone mastered. Recently though, more and more people have been building their own websites and scripting languages have become more important. Because of this, scripting languages are becomming easier to learn and PHP is one of the easiest and most powerful yet.

What Is PHP?

PHP stands for Hypertext Preprocessor and is a server-side language. This means that the script is run on your web server, not on the user's browser, so you do not need to worry about compatibility issues. PHP is relatively new (compared to languages such as Perl (CGI) and Java) but is quickly becomming one of the most popular scripting languages on the internet.

Why PHP?

You may be wondering why you should choose PHP over other languages such as Perl or even why you should learn a scripting language at all. I will deal with learning scripting languages first. Learning a scripting language, or even understanding one, can open up huge new possibilities for your website. Although you can download pre-made scripts from sites like Hotscripts, these will often contain advertising for the author or will not do exactly what you want. With an understanding of a scripting language you can easily edit these scripts to do what you want, or even create your own scripts.

Using scripts on your website allows you to add many new 'interactive' features like feedback forms, guestbooks, message boards, counters and even more advanced features like portal systems, content management, advertising managers etc. With these sort of things on your website you will find that it gives a more professional image. As well as this, anyone wanting to work in the site development industry will find that it is much easier to get a job if they know a scripting language.

What Do I Need?

As mentioned earlier, PHP is a server-side scripting language. This means that, although your users will not need to install new software, you web host will need to have PHP set up on their server. It should be listed as part of your package but if you don't know if it is installed you can find out using the first script in this tutorial. If you server does not support PHP you can ask your web host to install it for you as it is free to download and install. If you need a low cost web host which supports PHP I would recommmend HostRocket.

Writing PHP

Writing PHP on your computer is actually very simple. You don't need any specail software, except for a text editor (like Notepad in Windows). Run this and you are ready to write your first PHP script.

Declaring PHP

PHP scripts are always enclosed in between two PHP tags. This tells your server to parse the information between them as PHP. The three different forms are as follows:

<?
PHP Code In Here
?>

<?php
PHP Code In Here
php?>

<script language="php">
PHP Code In Here
</script>

All of these work in exactly the same way but in this tutorial I will be using the first option (<? and ?>). There is no particular reason for this, though, and you can use either of the options. You must remember, though, to start and end your code with the same tag (you can't start with <? and end with </script> for example).

Your First Script

The first PHP script you will be writing is very basic. All it will do is print out all the information about PHP on your server. Type the following code into your text editor:

<?
phpinfo();
?>

As you can see this actually just one line of code. It is a standard PHP function called phpinfo which will tell the server to print out a standard table of information giving you information on the setup of the server.

One other thing you should notice in this example is th
at the line ends in a semicolon. This is very important. As with many other scripting and programming languages nearly all lines are ended with a semicolon and if you miss it out you will get an error.

Finishing and Testing Your Script

Now you have finished your script save it as phpinfo.php and upload it to your server in the normal way. Now, using your browser, go the the URL of the script. If it has worked (and if PHP is installed on your server) you should get a huge page full of the information about PHP on your server.

If your script doesn't work and a blank page displays, you have either mistyped your code or your server does not support this function (although I have not yet found a server that does not). If, instead of a page being displayed, you are prompted to download the file, PHP is not installed on your server and you should either serach for a new web host or ask your current host to install PHP.

It is a good idea to keep this script for future reference.

Part 2

In this part I have introduced you to the basics of writing and running PHP. By this time you should now know if your host supports PHP and should have a basic understanding of how PHP scripts are structured. In part 2 I will show you how to print out information to the browser.

PHP 5.x is standard on iPage™ hosting (see tutorials for website setup help), which supports the most popular PHP scripts and content management systems.

A PHP Times Table Programme

2013-08-19T13:48:00.001-07:00

In the previous part, you saw what a For Loop was. In this section, we'll write a times table programme to illustrate how for loops work.
There's a script called timesTable.php amongst the files you downloaded (in the scripts folder). When loaded into the browser, it looks like this:
There's a script called timesTable.php amongst the files you downloaded (in the scripts folder.). When loaded into the browser, it looks like this:

What we're going to do is to get the values from the textboxes and create a Times Table proramme. When the button is clicked, the output will be something like this:

In other words, when the button is clicked we'll print the Times Table to the page. You can have a different Times Table, depending on what values you enter in the textboxes. To make a start with the coding, move on to the next part.

Some Practise with PHP If Statements

2013-08-19T13:47:00.002-07:00

We can use an if statement to display our image, from the previous section. If the user selected "church", then display the church image. If the user selected "kitten", then display another image (the kitten image, which is also in your images folder). Here's some code:

<?PHP

$kitten_image = 1;
$church_image = 0;

if ($kitten_image == 1) {

print ("<IMG SRC =images/kitten.jpg>");

}

Type that out, and save it as testImages.php. (Notice how there's no HTML!)
When you run the script, the kitten image should display. Let's look at the code and see what's happening.
The first two lines just set up some variables:

$kitten_image = 1;
$church_image = 0;

A value of 1 has been assigned to the variable called $kitten_image. A value of 0 has been assigned to the variable called $church_image. Then we have our if statement. Here it is without the print statement:

if ($kitten_image == 1) {

}

Notice how there's no semi-colon at the end of the first line - you don't need one. After the word "if" we have a round bracket. Then comes our variable name: $kitten_image. We want to test what's inside of this variable. Specifically, we want to test if it has a value of 1. So we need the double equals sign (==). The double equals sign doesn’t really mean “equals”. It means “has a value of”.
What we want to say is:

"If the variable called $kitten_image has a value of 1 then execute some code."

To complete the first line of the if statement we have another round bracket, and a left curly bracket. Miss any of these out, and you'll probably get the dreaded parse error!
The code we want to execute, though, is the print statement, so that our kitten image will display. This goes inside of the if statement:

if ($kitten_image == 1) {

print ("<IMG SRC =images/kitten.jpg>");

}

You need the semi-colon at the end of the print statement.
But if your if statement only runs to one line, you can just do this:

if ($kitten_image == 1) { print ("<IMG SRC = images/kitten.jpg>"); }

In other words, keep everything on one line. PHP doesn't care about your spaces, so it's perfectly acceptable code. Not very readable, but acceptable!
To make use of the church image, here's some new code to try:

<?PHP

$kitten_image = 0;
$church_image = 1;

if ($kitten_image == 1) {

print ("<IMG SRC =images/kitten.jpg>");

}

if ($church_image == 1) {

print ("<IMG SRC =images/church.jpg>");

}

Notice that the $kitten_image variable now has a value of 0 and that $church_image is 1. The new if statement is just the same as the first. When you run the script, however, the church image will display. That's because of this line:

if ($kitten_image == 1) {

That says, "If the variable called $kitten_image has a value of 1 ... ". PHP doesn't bother reading the rest of the if statement, because $kitten_image has a value of 0. It will jump down to our second if statement and test that:

if ($church_image == 1) {

Since the variable called $church_image does indeed have a value of 1, then the code inside of the if statement gets executed. That code prints out the HTML for the church image:

print ("<IMG SRC =images/church.jpg>");

In the next section, we'll take a look at if ... else statements.

What you need to get started with PHP

2013-08-19T13:46:00.002-07:00

Before you can write and test your PHP scripts, there's one thing you'll need - a server! Fortunately, you don't need to go out and buy one. In fact, you won't be spending any extra money. That's why PHP is so popular! But because PHP is a server-sided scripting language, you either have to get some web space with a hosting company that supports PHP, or make your computer pretend that it has a server installed. This is because PHP is not run on your PC - it's executed on the server. The results are then sent back to the client PC (your computer).
Don't worry if this all sounds a little daunting - we've come across an easier way to get you up and running. We're going to be using some software called Wampserver. This allows you to test your PHP scripts on your own computer. It installs everything you need, if you have a Windows PC. We'll explain how to get it installed in a moment, and where to get it from. But just a word for non-windows users.

Apple Users

If you have OS X, then try these sites to get up and running with PHP:

http://www.onlamp.com/pub/a/mac/2001/12/07/apache.html

http://www.entropy.ch/software/macosx/php/

What you're doing here is getting the apache server up and running, so that you can run PHP scripts offline. Pay particular attention to where files are stored, and to the "localhost" address.

Linux Users

There are quite a few sites out there to help Linux users get up and running with the Apache server and PHP. Here are three sites that are worth checking out:

http://en.wikipedia.org/wiki/LAMP_(software_bundle)

http://www.php-mysql-tutorial.com/wikis/php-tutorial/installing-php-and-mysql.aspx

http://www.phpfreaks.com/tutorials/12/0.php

If you know any better ones, we'd be interested in hearing from you!

Windows Users

OK, back to Wampserver and Windows. First, you need to download the software. You can get it from here (this site is nothing to do with ours, by the way):

Download Wampserver

Be sure to click the link for Presentation, as well as the link for Downloads. The Presentation page shows you how to install the file.

What is PHP?

2013-08-19T13:45:00.001-07:00

PHP is probably the most popular scripting language on the web. It is used to enhance web pages. With PHP, you can do things like create username and password login pages, check details from a form, create forums, picture galleries, surveys, and a whole lot more. If you've come across a web page that ends in PHP, then the author has written some programming code to liven up the plain, old HTML.
PHP is known as a server-sided language. That's because the PHP doesn't get executed on your computer, but on the computer you requested the page from. The results are then handed over to you, and displayed in your browser. Other scripting languages you may have heard of are ASP, Python and Perl. (You don't need to know any of these to make a start on PHP. In fact, these tutorials assume that you have no programming experience at all.)
The most popular explanation of just what PHP stands for is "Hypertext Pre-processor". But that would make it HPP, surely? An alternative explanation is that the initials come from the earliest version of the program, which was called Personal Home Page Tools. At least you get the letters "PHP" in the right order!
But PHP is so popular that if you're looking for a career in the web design/web scripting industry then you just have to know it! In these tutorials, we'll get you up and running. And, hopefully, it will be a lot easier than you think.

JavaScript: Password Validation using regular expressions and HTML5

2013-04-18T20:03:00.003-07:00

. Guidelines for Secure Password Input

Use the "password" input type

Instead of <input type="text"> you should always use <input type="password"> as this lets the browser (and the user) know that the contents of that field need to be secured. Your password won't appear on the screen as you type and most browsers also won't 'remember' the values entered in password fields as they do with other form elements.

Confirm password input

Because the password input type obscures the text typed, you should let the user confirm that they haven't made a mistake. The simplest way to do this is to have the password entered twice, and then check that they are identical.
Another method is to display what they've entered as part of a 'confirmation page'. The problem here is that you're making the password visible in the browser, browser cache, proxy, etc. For security a password should never be displayed in HTML or even sent by email.

Enforce 'strong' passwords

If you're concerned about security you should have some policy on what constitutes a valid password. Some common restrictions are:

at least n characters
combination of upper- and lower-case characters
one or more digits
not related to other user data (name, address, username, ...)
not a dictionary word

Leaving the last requirement for now, as it requires a server-side script, let's see what's possible using just client-side HTML and JavaScript.

Server security

While having a strong password is a good first step, it needs to be backed up by additional measures on the server that prevent brute-force attacks. One popular approach is to install Fail2Ban to monitor log files and lock out repeat offendors. Of course that only works if your login system reports failed login attempts to a system log file. Otherwise your application needs to provide this function.

2. Basic Demonstration

The form below has three input fields: username, pwd1 and pwd2. When the form is submitted the checkForm script parses the input values and returns either true or false. If a false value is returned then the form submission is cancelled.
This code will work for browsers as far back as Netscape 4 (circa 1997).
The code behind the form is as follows. If you're not sure how to place this on your page, you might need to read the preceding article on Form Validation, or view the HTML source of this page.

<script type="text/javascript">

  function checkForm(form)
  {
    if(form.username.value == "") {
      alert("Error: Username cannot be blank!");
      form.username.focus();
      return false;
    }
    re = /^\w+$/;
    if(!re.test(form.username.value)) {
      alert("Error: Username must contain only letters, numbers and underscores!");
      form.username.focus();
      return false;
    }

    if(form.pwd1.value != "" && form.pwd1.value == form.pwd2.value) {
      if(form.pwd1.value.length < 6) {
        alert("Error: Password must contain at least six characters!");
        form.pwd1.focus();
        return false;
      }
      if(form.pwd1.value == form.username.value) {
        alert("Error: Password must be different from Username!");
        form.pwd1.focus();
        return false;
      }
      re = /[0-9]/;
      if(!re.test(form.pwd1.value)) {
        alert("Error: password must contain at least one number (0-9)!");
        form.pwd1.focus();
        return false;
      }
      re = /[a-z]/;
      if(!re.test(form.pwd1.value)) {
        alert("Error: password must contain at least one lowercase letter (a-z)!");
        form.pwd1.focus();
        return false;
      }
      re = /[A-Z]/;
      if(!re.test(form.pwd1.value)) {
        alert("Error: password must contain at least one uppercase letter (A-Z)!");
        form.pwd1.focus();
        return false;
      }
    } else {
      alert("Error: Please check that you've entered and confirmed your password!");
      form.pwd1.focus();
      return false;
    }

    alert("You entered a valid password: " + form.pwd1.value);
    return true;
  }

</script>

expand code box

Remember that, as JavaScript isn't available in all browsers, you should user server-side scripting to validate all data before recording it in a database or text file. You might also want to spice up your forms using HTML5 Form Validation as we've done further down the page.

3. Advanced regular expressions

In the latest browsers - those that support JavaScript 1.5 (Firefox, Netscape 6/7, Mozilla, Safari and Opera 7) - you can use more powerful regular expressions. Older browsers will not recognise these patterns so the following is mostly useful for intranet rather than Internet applications.
The code presented above is fine in that it checks everything that we wanted to check, but uses a lot of code to test each requirement individually and present different error messages. We're going to show you now how to apply the password tests using a single regular expression.
Consider the following:

<script type="text/javascript">

  // at least one number, one lowercase and one uppercase letter
  // at least six characters
  var re = /(?=.*\d)(?=.*[a-z])(?=.*[A-Z]).{6,}/;
  var validPassword = re.test(input);

</script>

The type of expression used here is called a 'look-ahead' which tries to match the contained regexp against the 'future' part of the string.
Translation:

matches a string of six or more characters;
that contains at least one digit (\d is shorthand for [0-9]);
at least one uppercase character; and
at least one lowercase character:

input	result of test	reason
abcABC	false	no numbers
abc123	false	no uppercase characters
abAB1	false	too short
abAB12	true	-
Aa123456	true	-

If you are using a supported browser you can use the form below to test the regular expression:
If you want to restrict the password to ONLY letters and numbers (no spaces or other characters) then only a slight change is required. Instead of using . (the wildcard) we use \w:

<script type="text/javascript">

  // at least one number, one lowercase and one uppercase letter
  // at least six characters that are letters, numbers or the underscore
  var re = /^(?=.*\d)(?=.*[a-z])(?=.*[A-Z])\w{6,}$/;
  var validPassword = re.test(input);

</script>

The \w is shorthand for 'any letter, number or the underscore character'.
Again, you can use the form below to test this regular expression:

4. Sample HTML and JavaScript code

You might implement this code on your own website as follows:

<script type="text/javascript">

  function checkPassword(str)
  {
    var re = /^(?=.*\d)(?=.*[a-z])(?=.*[A-Z])\w{6,}$/;
    return re.test(str);
  }

  function checkForm(form)
  {
    if(form.username.value == "") {
      alert("Error: Username cannot be blank!");
      form.username.focus();
      return false;
    }
    re = /^\w+$/;
    if(!re.test(form.username.value)) {
      alert("Error: Username must contain only letters, numbers and underscores!");
      form.username.focus();
      return false;
    }
    if(form.pwd1.value != "" && form.pwd1.value == form.pwd2.value) {
      if(!checkPassword(form.pwd1.value)) {
        alert("The password you have entered is not valid!");
        form.pwd1.focus();
        return false;
      }
    } else {
      alert("Error: Please check that you've entered and confirmed your password!");
      form.pwd1.focus();
      return false;
    }
    return true;
  }

</script>

<form method="POST" action="form-handler.php" onsubmit="return checkForm(this);">
<p>Username: <input type="text" name="username"></p>
<p>Password: <input type="password" name="pwd1"></p>
<p>Confirm Password: <input type="password" name="pwd2"></p>
<p><input type="submit"></p>
</form>

As you can see, it's well worth learning the intricacies of regular expressions. They can be used not just in JavaScript, but also PHP, Perl, Java and many other languages. Some text editors (not just vi) also allow them when searching for or replacing text.

5. HTML5 Form Validation

We earlier mentioned HTML5 form validation. This is a new technique available in modern browsers and definitely the way of the future. A few simple form attributes can have the same effect as reams of JavaScript code libraries.
Here we have an enhanced version of the above code where we've added HTML5 required and pattern elements to apply regular expression tests within the form itself in supporting browsers. Helpfully the regular expression syntax is identical with just the /^ and $/ removed.
We've also added a tricky little onchange handler to the first password field which updates the pattern required by the second password field - in effect forcing them to be identical:
Here you can see a screen shot from Safari of the form being completed. The red/green markers have been implemented using CSS:

In this example it should be clear to the user that the form can only be submitted once all three green ticks appear. In any case browsers such as Firefox and Opera will enforce the HTML5 validation rules and present messages as shown here:

Presumably the browser messages will change according to the users language - something that would never be possible using only JavaScript.
All we have changed from the previous example is to add some extra attributes to the form input fields. The rest of the HTML and JavaScript remains unaltered:

...
<p>Username: <input type="text" required pattern="\w+" name="username"></p>
<p>Password: <input type="password" required pattern="(?=.*\d)(?=.*[a-z])(?=.*[A-Z])\w{6,}" name="pwd1" onchange="form.pwd2.pattern = this.value;"></p>
<p>Confirm Password: <input type="password" required pattern="(?=.*\d)(?=.*[a-z])(?=.*[A-Z])\w{6,}" name="pwd2"></p>
...

The best thing about HTML5 attributes is that they have no effect whatsoever on unsupported browsers, so Internet Explorer will act as if they are not present and simply run the JavaScript as before.
At this stage both Firefox and Opera enforce HTML5 validation attributes in the browser while Safari only lets you use them in combination with CSS effects.

6. Customised HTML5 browser alerts

As you can see from the screenshot above the alert message in Firefox for when the input doesn't match the pattern attribute is simply "Please match the requested format.". Not entirely helpful in this case where we have a number of different requirements.
Fortunately it is possible to customise this message using just a touch of JavaScript.
The only change between this and the previous example is that we've modified the onchange handler for the Password input and added one for Confirm Password:

...
<p>Password: <input type="password" required pattern="(?=.*\d)(?=.*[a-z])(?=.*[A-Z])\w{6,}" name="pwd1" onchange="
  this.setCustomValidity(this.validity.patternMismatch ? 'Password must contain at least 6 characters, including UPPER/lowercase and numbers' : '');
  if(this.checkValidity()) form.pwd2.pattern = this.value;
"></p>
<p>Confirm Password: <input type="password" required 
pattern="(?=.*\d)(?=.*[a-z])(?=.*[A-Z])\w{6,}" name="pwd2" onchange="
  this.setCustomValidity(this.validity.patternMismatch ? 'Please enter 
the same Password as above' : '');
"></p>
...

When the Password input is changed we check its validity.patternMismatch flag to see whether it matches the pattern attribute. If it doesn't match we set a custom error message to appear when the form is submitted.
Whenever setCustomValidity() has been used to set a custom message the field in question will be regarded as invalid and prevent the form from submitting (at least in Firefox and Opera). To reverse this it needs to be set to blank, which we do when the input matches our regex rules.
The custom message we have set appears in Firefox as shown here:

You can see from the code that we have applied a similar technique to the Confirm Password field so it will now display "Please enter the same Password as above" if there is a mismatch between the two fields. Basically what we've achieved here is to replicate our JavaScript validation script using HTML5.
Because we are only checking for patternMismatch we are not affecting the other default validation options - namely the required attribute - so submitting the form with blank fields will still display the generic "Please fill out this field" alert message. To override those errors you would need to check the validity.valueMissing flag.

7. Conclusions

As you can see there's a lot involved in providing a rich user experience even for something as simple as changing a password. To summarise what we've covered:

Always start by emailing new users a random password or unique activation link;
Use the password input type to prevent passwords appearing on screen;
Decide what constitutes a 'strong' password for your system and enforce it:
- server-side for spambots and users with JavaScript disabled;
- using JavaScript for browsers that don't support HTML5 validation;
- using HTML5 for a more user-friendly experience;
Use CSS rules to highlight valid/invalid input for browsers that don't have alerts built-in; and
Customise the HTML5 error messages where appropriate for improved usability;

Most of all don't feel you have to install massive JavaScript or jQuery libraries just to validate a form. By taking advantage of new browser standards as show in this article you can save time and resources and at the same time provide a better user experience.

Passing variables to JavaScript usin php

2013-04-18T19:29:00.000-07:00

1. Escaping Quotes and Line Breaks

Suppose you start with a PHP variable that needs to be displayed in a JavaScript alert or confirmation dialog:

  $message = "a short piece of text
spanning more than one line
and containing \"double\" & 'single' quotes";

The obvious way to turn this into an alert is:

<script type="text/javascript">
  alert("<?PHP echo $message ?>");
</script>

but that results in invalid JavaScript code:

<script type="text/javascript">
  alert("a short piece of text
spanning more than one line
and containing "double" & 'single' quotes");
</script>

There are two problems. Firstly, having line breaks inside a JavaScript variable is not an option. They'll need to be replaced with \n (character representation of a line break). Secondly, the double quotes inside the text conflict with the outer quotes of the alert call.
Learning from our mistakes, here's some code that actually works:

<script type="text/javascript">
  alert("<?php echo preg_replace("/\r?\n/", "\\n", addslashes($message)); ?>");
</script>

The above code relies on PHP being embedded within HTML code. If you're outputting the entire page from PHP then you need to go a step further:

  $message = preg_replace("/\r?\n/", "\\n", addslashes($message));
  echo "<script type=\"text/javascript\">\n";
  echo "  alert(\"$message\");\n";
  echo "</script>\n\n";

The output is now:

<script type="text/javascript">
  alert("a short piece of text\nspanning more than one line\nand containing \"double\" & \'single\' quotes");
</script>

The same approach can be applied in pretty much any situation where PHP needs to pass variables to JavaScript.
When trying to debug this kind of code you should always check first what's valid in JavaScript (most modern browsers have a built-in debugger for this) and only then see how it can be generated from PHP.
Note: It's not necessary to encode characters such as & and " to their HTML entities as JavaScript is a separate language from HTML and can handle them without problem.

Exporting Data to Excel usin php

2013-04-18T19:04:00.000-07:00

1. Preparing the data

The following examples use the dataset created for Sorting Arrays of Arrays which is defined as follows:

<?PHP
  $data = array(
    array("firstname" => "Mary", "lastname" => "Johnson", "age" => 25),
    array("firstname" => "Amanda", "lastname" => "Miller", "age" => 18),
    array("firstname" => "James", "lastname" => "Brown", "age" => 31),
    array("firstname" => "Patricia", "lastname" => "Williams", "age" => 7),
    array("firstname" => "Michael", "lastname" => "Davis", "age" => 43),
    array("firstname" => "Sarah", "lastname" => "Miller", "age" => 24),
    array("firstname" => "Patrick", "lastname" => "Miller", "age" => 27)
  );
?>

Note: Further down this page you can find an example on creating an export from an SQL query.
The first step is to output the data in a tab-delimited format (CSV can also be used but is slightly more complicated). To achieve this we use the following code:

<?PHP
  header("Content-Type: text/plain");

  $flag = false;
  foreach($data as $row) {
    if(!$flag) {
      // display field/column names as first row
      echo implode("\t", array_keys($row)) . "\r\n";
      $flag = true;
    }
    echo implode("\t", array_values($row)) . "\r\n";
  }
  exit;
?>

We set the content type to text/plain so that the output can more easily be viewed in the browser. Otherwise, because there is no HTML formatting, the output would appear as a single line of text.
The first line of output will be the column headings (in this case the field names are used). Values are separated with a tab \t and rows with a line break \n. The output should look something like the following:

firstname lastname age
Mary Johnson 25
Amanda Miller 18
James Brown 31
Patricia Williams 7
Michael Davis 43
Sarah Miller 24
Patrick Miller 27

There's already a weakness in this code that may not be immediately obvious. What if one of the fields to be ouput already contains one or more tab characters, or worse, a newline? That's going to throw the whole process out as we rely on those characters to indicate column- and line-breaks.
The solution is to 'escape' the tab characters. In this case we're going to replace tabs with a literal \t and line breaks with a literal \n so they don't affect the formatting:

<?PHP
  function cleanData(&$str)
  {
    $str = preg_replace("/\t/", "\\t", $str);
    $str = preg_replace("/\r?\n/", "\\n", $str);
  }

  header("Content-Type: text/plain");

  $flag = false;
  foreach($data as $row) {
    if(!$flag) {
      // display field/column names as first row
      echo implode("\t", array_keys($row)) . "\r\n";
      $flag = true;
    }
    array_walk($row, 'cleanData');
    echo implode("\t", array_values($row)) . "\r\n";
  }
  exit;
?>

Now, before each row is echoed any tab characters are replaced "\t" so that our columns aren't broken up. Also any line breaks within the data are replaced with "\n". Now, how to set this up as a download...

2. Triggering a download

What many programmers don't realise is that you don't have to create a file, even a temporary one, in order for one to be downloaded. It's sufficient to 'mimic' a download by passing the equivalent HTTP headers followed by the data.
If we create a PHP file with the following code then when it's called a file will be downloaded which can be opened directly using Excel.

<?PHP
  function cleanData(&$str)
  {
    $str = preg_replace("/\t/", "\\t", $str);
    $str = preg_replace("/\r?\n/", "\\n", $str);
    if(strstr($str, '"')) $str = '"' . str_replace('"', '""', $str) . '"';
  }

  // filename for download
  $filename = "website_data_" . date('Ymd') . ".xls";

  header("Content-Disposition: attachment; filename=\"$filename\"");
  header("Content-Type: application/vnd.ms-excel");

  $flag = false;
  foreach($data as $row) {
    if(!$flag) {
      // display field/column names as first row
      echo implode("\t", array_keys($row)) . "\r\n";
      $flag = true;
    }
    array_walk($row, 'cleanData');
    echo implode("\t", array_values($row)) . "\r\n";
  }
  exit;
?>

Note that we've added an extra line to the cleanData function to detect double-quotes and escape any value that contains them. Without this an uneven number of quotes in a string can confuse Excel.

This should result in a file being downloaded and saved to your computer. If all goes well then the filename will be named "website_data_20130419.xls" and will open in Excel looking something like this:

How does it work? Setting the headers tells the browser to expect a file with a given name and type. The data is then echoed, but instead of appearing on the page it becomes the downloaded file.
Because of the .xls extension and the ms-excel file type, most computers will associate it with Excel and double-clicking will cause that program to open. You could also modify the file name and mime type to indicate a different spreadsheet package or database application.
There is no way to specify data or cell formatting, column widths, etc, using this method. We are only passing a tab-delimited text file. To include formatting try generating HTML code or a script that actually builds an Excel file. Or create your own macro in Excel that applies formatting after the import.
A similar technique can be used to allow users to download files that have been uploaded previously using PHP and stored with different names. More on that later...

3. Exporting from an SQL database

If your goal is to allow data to be exported from a query result then the changes are relatively simple:

<?PHP
  // Original PHP code by Chirp Internet: www.chirp.com.au
  // Please acknowledge use of this code by including this header.

  function cleanData(&$str)
  {
    $str = preg_replace("/\t/", "\\t", $str);
    $str = preg_replace("/\r?\n/", "\\n", $str);
    if(strstr($str, '"')) $str = '"' . str_replace('"', '""', $str) . '"';
  }

  // filename for download
  $filename = "website_data_" . date('Ymd') . ".xls";

  header("Content-Disposition: attachment; filename=\"$filename\"");
  header("Content-Type: application/vnd.ms-excel");

  $flag = false;
  $result = pg_query("SELECT * FROM table ORDER BY field") or die('Query failed!');
  while(false !== ($row = pg_fetch_assoc($result))) {
    if(!$flag) {
      // display field/column names as first row
      echo implode("\t", array_keys($row)) . "\r\n";
      $flag = true;
    }
    array_walk($row, 'cleanData');
    echo implode("\t", array_values($row)) . "\r\n";
  }
  exit;
?>

This would be the entire file required to query the database and trigger the file download. The database functions need to match the database you're using. MySQL users for example will need to use mysql_query and either mysql_fetch_assoc or mysqli_fetch_assoc in place of the PostgreSQL functions.
For other databases see under User Comments below or check the PHP documentation. If you are seeing duplicate columns (numbered as well as labeled) you need to change the fetch call to return only the associative (ASSOC) array.
If you're having trouble at this stage, remove the Content-Disposition header and change the Content-Type back to text/plain. This makes debugging a lot easier as you can see the output in your browser rather than having to download and open the generated file every time you edit the script.

4. Preventing Excel's ridiculous auto-format

When importing from a text file as we're essentially doing here, Excel has a nasty habit of mangling dates, timestamps, phone numbers and similar input values.
For our purposes, some simple additions to the cleanData function take care of most of the problems:

<?PHP
  // Original PHP code by Chirp Internet: www.chirp.com.au
  // Please acknowledge use of this code by including this header.

  function cleanData(&$str)
  {
    // escape tab characters
    $str = preg_replace("/\t/", "\\t", $str);

    // escape new lines
    $str = preg_replace("/\r?\n/", "\\n", $str);

    // convert 't' and 'f' to boolean values
    if($str == 't') $str = 'TRUE';
    if($str == 'f') $str = 'FALSE';

    // force certain number/date formats to be imported as strings
    if(preg_match("/^0/", $str) || preg_match("/^\+?\d{8,}$/", $str) || preg_match("/^\d{4}.\d{1,2}.\d{1,2}/", $str)) {
      $str = "'$str";
    }

    // escape fields that include double quotes
    if(strstr($str, '"')) $str = '"' . str_replace('"', '""', $str) . '"';
  }
?>

The section that prevents values being scrambled does so by inserting an apostrophe at the start of the cell. When you open the resuling file in Excel you may see the apostrophe, but editing the field will make it disappear while retaining the string format. Excel is strange that way.
The types of values being escape this way are: values starting with a zero; values starting with an optional + and at least 8 consecutive digits (phone numbers); and values starting with numbers in YYYY-MM-DD format (timestamps). The relevant regular expressions have been highlighted in the code above.

5. Formatting - colours, numbers, dates

Again, this script generates and triggers the download of a tab-delimited text file with an .xls extension and Excel Mime-Type. We are not building an actual Excel document.
Defining styles, colours, column widths, etc, is not possible using this technique. You may be able to generate an HTML table with some formatted data that Excel will recognise, otherwise you need a much more complicated script.

6. Exporting to CSV format

The tab-delimited text options describe above may be a bit limiting if your data contains newlines or tab breaks that you want to preserve when opened in Excel or another spreadsheet application.
A better format then is comma-separated variables (CSV) which can be generated as follows:

<?PHP
  function cleanData(&$str)
  {
    if($str == 't') $str = 'TRUE';
    if($str == 'f') $str = 'FALSE';
    if(preg_match("/^0/", $str) || preg_match("/^\+?\d{8,}$/", $str) || preg_match("/^\d{4}.\d{1,2}.\d{1,2}/", $str)) {
      $str = "'$str";
    }
    if(strstr($str, '"')) $str = '"' . str_replace('"', '""', $str) . '"';
  }

  // filename for download
  $filename = "website_data_" . date('Ymd') . ".csv";

  header("Content-Disposition: attachment; filename=\"$filename\"");
  header("Content-Type: text/csv;");

  $out = fopen("php://output", 'w');

  $flag = false;
  $result = pg_query("SELECT * FROM table ORDER BY field") or die('Query failed!');
  while(false !== ($row = pg_fetch_assoc($result))) {
    if(!$flag) {
      // display field/column names as first row
      fputcsv($out, array_keys($row), ',', '"');
      $flag = true;
    }
    array_walk($row, 'cleanData');
    fputcsv($out, array_values($row), ',', '"');
  }

  fclose($out);
  exit;
?>

Normally the fputcsv command is used to write data in CSV format to a separate file. In this script we're tricking it into writing directly to the page by telling it to write to php://output instead of a regular file.

7. Exporting to CSV with Unicode intact

If like us your data contains UTF-8 characters you will notice that Excel doesn't handle them very well. Other applications can open UTF-8 content without problems, but for some reason Microsoft wants to keep you in the dark ages.
Fortunately, there is a trick you can use. Below you can see how we modify the script to convert everything from UTF-8 to UTF-16 Lower Endian (UTF-16LE) format which Excel, at least on Windows, will recognise.
Please Note: When you open the file in Excel you might find all the data bunched into the first column. This should be fixable using the "Text to Columns..." command in the Data menu.

<?PHP
  function cleanData(&$str)
  {
    if($str == 't') $str = 'TRUE';
    if($str == 'f') $str = 'FALSE';
    if(preg_match("/^0/", $str) || preg_match("/^\+?\d{8,}$/", $str) || preg_match("/^\d{4}.\d{1,2}.\d{1,2}/", $str)) {
      $str = "'$str";
    }
    if(strstr($str, '"')) $str = '"' . str_replace('"', '""', $str) . '"';
    $str = mb_convert_encoding($str, 'UTF-16LE', 'UTF-8');
  }

  // filename for download
  $filename = "website_data_" . date('Ymd') . ".csv";

  header("Content-Disposition: attachment; filename=\"$filename\"");
  header("Content-Type: text/csv; charset=UTF-16LE");

  $out = fopen("php://output", 'w');

  $flag = false;
  $result = pg_query("SELECT * FROM table ORDER BY field") or die('Query failed!');
  while(false !== ($row = pg_fetch_assoc($result))) {
    if(!$flag) {
      // display field/column names as first row
      fputcsv($out, array_keys($row), ',', '"');
      $flag = true;
    }
    array_walk($row, 'cleanData');
    fputcsv($out, array_values($row), ',', '"');
  }

  fclose($out);
  exit;
?>

This script may not work for all versions of Excel. Please let us know using the Feedback form below if you encounter problems or come up with a better solution.

8. Specifying column headings

The above database download examples all use the database field names for the first row of the exported file which may not be what you want. If you want to specify your own more user-friendly headings you can modify the code as follow:

<PHP
  $colnames = array(
    'memberno' => "Member No.",
    'date_joined' => "Date joined",
    'title' => "Title",
    'firstname' => "First name",
    'lastname' => "Last name",
    'address' => "Address",
    'postcode' => "Postcode",
    'city' => "City",
    'country' => "Country",
    'phone' => "Telephone",
    'mobile' => "Mobile",
    'fax' => "Facsimile",
    'email' => "Email address",
    'notes' => "Notes"
  );

  function map_colnames($input)
  {
    global $colnames;
    return isset($colnames[$input]) ? $colnames[$input] : $input;
  }

  // filename for download
  $filename = "website_data_" . date('Ymd') . ".csv";

  ...

    if(!$flag) {
      // display field/column names as first row
      $firstline = array_map("map_colnames", array_keys($row));
      fputcsv($outstream, $firstline, ',', '"');
      $flag = true;
    }

   ...

?>

The values in the first row will be mapped according to the $colnames associative array. If no mapping is provided for a fieldname it will remain unchanged. Of course you will want to provide your own list of suitable headings. They don't have to be in order.

Why do you need an Ecommerce website?

2013-03-26T06:23:00.000-07:00

If you’re looking to sell your products online, you would need an Ecommerce store. Who does not want a fully featured site or portal for less money? We can provide you tailor made solutions for your online shopping needs matching your budget. You can easily make profits with our custom Ecommerce solutions.

At Infilon, we keep in mind the target audience while designing and developing any Ecommerce store. Our designs are influenced by who is going to buy your products. All the websites we build are user friendly and creative. We do not do what everybody does and that makes us distinguish from the crowd. We can make your Ecommerce website stand out from the pool of websites.

We have helped many small and large businesses make huge profits with having an online presence. Once you come to us, you can get tension-free about the development and you can focus on your core business. Now, you don’t need to spend thousands of dollars for having an Ecommerce store. We provide cost effective solutions for all your Ecommerce needs.

There might be countless competitors in your business. So standing out of the competition is mandatory. We analyse the markets and then come to an idea and plan to design an Ecommerce website for you. At Infilon, we can help you build a larger turn over in no time. The experts at Infilon always strive to create new ways to enhance our services and help our clients to get the maximum Returns on Investment.

The key to a successful Ecommerce website is easy navigation, user-friendly, multiple payment options and content. After the development, you would obviously need branding. We prepare a good marketing strategy for your website or portal. The key to a successful and profit-generating ecommerce website is easy navigable, user friendly, multiple payment options and easy search options.

You should make your website customers’ favorite and their shopping experience with your website memorable. With years of experience, we know how to offer a high conversion ratio for your products. By using our Ecommerce solutions, showcase your products to the world and build a flourishing online business.

what is new in windows 8 server ?

2013-03-23T18:15:00.003-07:00

Hello again. This is another article about Windows 8. But this time I will talk about the server version of this operating system. As you all know, approximately 1 month ago, Microsoft made the Developer Preview of its next generation operating system available through its MSDN website. The installation of the operating system is somehow similar (but shorter) to the installation of its client version brother. But the interior is different of course. Let me first show you the installation and then I will talk about new features coming with the Server 8.

The ISO file of the setup DVD for Windows 8 Server is reachable through the MSDN site as I mentioned before. Therefore if you are an MSDN subscriber, you can download it via http://msdn.microsoft.com/en-us/subscriptions/downloads/default.aspx . As you can see in Figure 1, you have to sign in to the website and you must have the permission to download this server product.

Figure 1: MSDN Subscriber webpage

You may want to read the system requirements for Windows Server 8 Developer Preview installation first. This information can be reached through http://msdn.microsoft.com/en-us/windowsserver/hh440457 webpage (actually using resources less than the ones mentioned in the webpage doesn’t prevent the installation to be completed).
OK. Let me start with the installation process now. After I insert my installation DVD into my server, I boot the server with it and the first screen is (as usual) time/keyboard/language selection screen as seen in Figure 2. After I complete the selections, I begin to install Windows 8 Server by pressing “Install Now” button on the next screen (Figure 3).

Figure 2: Time/keyboard/language selection screen

Figure 3: “Install now”

The following screen is the selection of the operating system type screen. Here, I have three types of operating system to install and I select the first choice which is full installation (Figure 4). In here, a very new installation type “Features on Demand” is also listed (which I am not very familiar with for now). The next 3 screens are License Agreement, type of installation (upgrade or Custom) and disk selection screens. After a couple of Next buttons, I finish the installation of Developer Preview edition of the new Windows operating system. The first screen represented after a reboot is “Settings” screen which is actually the place that I decide the administrators password (Figure 5). That is all :) . No more questions. This represents me the CTRL+ALT+DEL screen (Figure 6) and I logon to my new server.

Figure 4: Operating System types

Figure 5: Settings screen

Figure 6: CTRL+ALT+DEL screen

After I logon to the operating system, “Server Manager” window is opened automatically. It is completely different than its predecessors as you can see in Figure 7. I will not get into detail about it now because we will play with it in future articles. Therefore that is end of installation part. Not that difficult, huh?

Figure 7: New “Server manager” interface

Now I want to talk about the new features coming with this new operating system. According to the Windows guys, there are 300 new features/improvements in this version but I couldn’t explain all of them of course :) . Therefore I will talk about the most important ones (according to me).
You saw Server Manager in Figure 7 and as you understand it had a new Metro Style interface. That is not I am going to talk about Server Manager but it has a new capability now. You can do multiserver management via Server Manager of Windows 8 Server (Figure 8). What I mean by this? With Server Manager, you can (for example) install updates, reboot and load File Services Role or DNS role on four servers simultaneously. No need to do one by one.

Figure 8: You can put additional servers in the list to add the same role simultaneously

Another new feature (actually an improvement) is Hyper-V version 3. It has new specifications now (and may change with RTM). Hyper-V version 3 supports 160 CPU cores and 2TB memory on host machines. It supports 32 CPU cores and 512 GB memory per virtual machine. Another feature it has is the new file format VHDX. VHDX can exceed 2TB in size and runs faster than VHD format. Hyper-V version 3 can grow up to 63 nodes in a cluster and supports 4000 virtual machines per cluster.
Windows 8 Server can team the network cards natively. Before Windows 8 Server, we can team the network cards with the manufacturer’s teaming tools/softwares but now it is not needed. Most importantly, we can team NICs that have totally different chipsets. Therefore Windows can load balance the network job and if one of the NICs fails, It continues its job seamlessly.
One of the coolest feature that Windows 8 Server introduces is Dynamic Access Control. It is a new approach for file/folder permissions. To be clear, it uses tags for file/folder access (like Microsoft Office Tags). For example, you can give each personnel of the Finance department a specific title in Active Directory and Windows 8 File Server can use the Active Directory Title Attribute as a tag. As a result, it lets the personnel reach the files and folders which are classified for this tag. This feature may rescue administrators from too many security groups which are created just for giving permissions on file server.
The last feature that I want to mention in this article is de-duplication feature. If there are files with multiple copies in the hard drive, Windows 8 Server can save space by keeping one real copy of them and pointer for the rest. For example, you have multiple Windows Server 2003 virtual machines created on your Windows 8 Hyper-V server and each of these virtual machines have calculator.exe file. Windows 8 Server knows about these redundant files and keep only one of them. The rest is just pointers to this kept one. I think you got the idea ;)
Hopefully and most probably, there will be more stuff in Windows 8 Server when it is released. I tried to mention the most important ones (in my opinion) in this article. I hope you enjoyed it. See you next time.

what is new in windows 8 ?

2013-03-23T18:13:00.001-07:00

Last weeks Microsoft released the Developer Preview for its new operating system, Windows 8, to public. It is known that Windows 8 Final Release will be available in 2012. As all new operating systems come with improvements and differences, Windows 8 promises to give customers a new and improved Windows experience. Throughout this article, I want to show you some of these new features of Windows 8.

Windows 8 Developer Preview can be downloaded through the link http://msdn.microsoft.com/en-us/windows/apps/br229516 . The operating system is coming with 32bit and 64 bit options. I will explain the main differences of Windows 8 but you can reach a long list of new Windows 8 features in winrumors.com website. So what are the main newly coming features of Windows 8?
The first thing a user will notice is metro style user interface (Figure 1). This interface is mainly designed for tablets and is build for touch. You can access your applications (Apps) from this single interface with a fingertip. This interface is a personalized layout with clean animations and writings to make the user interact with his/her PC fluid. The new Start screen puts everything you want and you need in front of you for immediate access. It is also alive! What I mean by that is the Apps show user up-to-date information as long as your device is connected to the internet. Therefore, you can access the information as it produced.

Figure 1: Metro Style start screen

Previous Windows client operating systems support x86 or x64 platforms. Another new feature of Windows 8 is its ARM support. As the new Windows 8 operating system is mainly designed for mobile devices, it supports ARM-based chipsets now. The users will experience their new Windows in various types of devices such as a 10-inch tablet or ultra lightweight laptops.
Cloud computing is seen as the future of computing world today and Applications (as in the Android operating system) is the new trend in IT world. Therefore Microsoft implements its application solution to Windows 8 (Apps). Windows Store (identical to Google Android Market) will serve as a central point for application downloads. Windows Apps can work together by the way; making it easy to search, share, and send content between them. As I said before, when a user is connected to the Internet, Apps come alive with activity and show the latest content. May be the most powerful side of Windows Apps is their ability to come with the user! As a user sign in with his connected Microsoft account (LiveID) to another PC running Windows 8, his Metro style apps and settings go with him, so it’s just like using his own PC.
Another improvement Windows 8 has is the faster boot start. In windows8center.com website, there is a good explanation of why it is faster than its predecessors. Figure 2 shows the comparison of Windows 8 and Windows 7 boot up speeds for various PC configurations. Therefore, one of the most frastrating downside (long startup time) of Windows operating systems is not a downside anymore. :)

Figure 2: Windows 8 vs Windows 7 boot start comparison (taken from windows8center.com)

Windows 8 supports USB 3.0 standard natively. As I talked about USB standard, there is a big improvement that Windows 8 can be booted from a USB memory stick. This feature which is called “Windows To Go” will be very helpful especially for system administrators I think. You can boot a corrupted or infected machine with Windows 8 and perform administrative tasks on that. Also a user can bring his operating system with him wherever he wants. Just plug the stick in, work as he wants, finish the job and plug the operating system out. :)
Uptil now, I talked about the general changes that the new operating system has over the previous one. But what about the user experience? Is there any changes or improvements in Windows while we are using it? Let me talk about it from now on.
Task Manager looks different now (Figure3). It is easy-to-use and all-in-one dashboard for monitoring the PC’s resources and services. The data is presented in color-coded tiles to point out the items that are using the bulk of a resource. There are 7 tabs included in Task Manager now which are; Processes, Performance, App History, Startup, Users, Details and Services.

Figure 3: New Task Manager

Another new feature (which is not a big one but very important in my opinion) is the ability to mount ISO and VHD files natively. From now on with Windows 8, you can mount your ISO files as CD-Drive and your VHD files as harddisks without needing a third party solution. As an administrator, one of the first things that I’ve done is to install a mounting software to my operating system. With Windows 8, I don’t need it anymore (Figure 4).

Figure 4: Mounting ISO and VHD files

Windows Explorer has a big difference now because it has a ribbon bar which organizes the rich functionality of Explorer (Figure 5). Mostly used commands are now organized in ribbon and users can reach most of the functionalities with one mouse click.

Figure 5: Ribbon bar of Windows Explorer

Other than these, few additional changes that the users experience at first glance are Internet Explorer 10, Push-button Reset, Lock Screen & Notifications, LiveID logon. As I said before there will be lots of improvements when Windows 8 is on the market. You can read more explanation about the new features in http://download.microsoft.com/download/1/E/4/1E455D53-C382-4A39-BA73-55413F183333/Windows_Developer_Preview-Windows8_guide.pdf .
I think Windows 8 will be a realistic change for Microsoft and the real first step to cloud computing on the client side. It seems that user habits will change with this new release. Users will get what they want from the operating system more easily and friendly. I hope the article is helpful to you. See you next time.

top 10 favorite Twitter tips and tricks

2013-03-22T19:03:00.003-07:00

Below is a listing of our top 10 favorite Twitter tips and tricks. These tips will help make your Twitter experience more enjoyable and can help increase your followers.
Customize

Change your profile picture. Use a picture of yourself to make it seem more personalized if this is your personal Twitter account.
Utilize as much of the 160-character limit Twitter BIO space allows. Include keywords your followers or potential followers may be searching for.
Create your own background image. However, do not make the image too much like an ad or sales pitch. The background image must be less than 800k and we recommend a size of 1600x1200 for a large image or smaller if you plan on tiling the image or just having it on the left-hand side. Finally, keep in mind that smaller resolutions and monitor sizes will hide much of the background.

Third-party tools

Take advantage of the hundreds of different third-party online tools and services that enhance your Twitter experience. Below are a few of our favorites.

TwitPic - Take advantage of TwitPic to post pictures on your tweets. If you want to post pictures while away from the computer, use the Twitterific app.
Qwitter - Great service that sends an e-mail any time someone unsubscribes from your Twitter profile and mentions a possible Twitter post you made that may have caused them to leave.
Manageflitter - Fantastic site for managing your followers and getting an easy to read overview of people not following you back, quiet users, and inactive users.
WeFollow - Great website that allows you to add yourself to a listing of Twitter users by tags you find interesting.
SocialOomph - Another great service with a collection of free Twitter tools including the ability to schedule when a tweets gets posted.
Tweetbeat - An excellent site that takes the trending topics on Twitter and gives you a clearer explanation of present and past trending topics.
TwitterMeme - Another great location to find the hottest links on Twitter.
Twitter Grader - Great service that grades any Twitter account and gives you additional details and ranking information.
Twitter Fan Wiki Apps - Finally, this wiki has a listing of several hundred different Twitter applications and tools for users wanting more.

Use Twitter search

Take full advantage of the Twitter search tool. Below are just a few tips that can help improve your search capabilities on Twitter.

Search for your website or blog URL and see if others are mentioning your page.
Search for anything near you by adding near:"city state". For example, typing near:"Salt lake city Utah" club would return current tweets that have happened in Salt Lake City, Utah with the keyword club in them.
Find people who you may enjoy following by searching for keywords that interested you.
If you do not want tweets with links add ? -filter:links at the end of your search query.
Need more options, use the Advanced Twitter search.
Any time you get excellent results click the "Save this search" button to save that search. These searches can then be found under "Saved Searches" on the right-hand part of your profile on the old Twitter interface or under the "Searches" tab next to your timeline on the new Twitter interface.

Followers

Engage followers.
Do not follow too many people. No one is going to follow someone who is following thousands of people but only has 10 followers.
Retweet interesting posts.
Retweet and participate in conversations with people with a lot of followers.
Realize it is impossible for anyone to read every tweet.
When first joining do not follow hundreds of people, doing this may mark you as a bot.

Create useful and interesting tweets

Try making all your tweets informative, useful, or funny.
Do not post mundane posts, e.g. eating a bowl of cereal.
Add hastags to your tweets. For example, if your tweet is about computers, consider adding #computer in the tweet.
Tweet frequently. No one is going to follow someone they do not know who has not tweeted in months. Try at the very least to tweet a few times a week or daily if you can manage.
Do not whine or complain. Everyone will unfollow anyone who constantly whines or complains.
Try making your valuable tweets during the times people will most likely see them.
Keep some space available in your tweet in case someone retweets your post.
Use special characters in your tweets.

Know the lingo

Know the Twitter lingo, these are just a few examples: @reply, Direct Message (DM), Follower, Hashtag, Retweet (RT), Trending Topics, and Tweet. See the Twitter description for a full listing of Twitter terms and Lingo and related terms.

Follow the masters

Following a few of the masters of Twitter and Social Networking will give you an understanding of how to tweet better, posts to RT, and inspiration for tweets of your own. Below are the top ten Twitters we recommend following.

@GuyKawasaki
@Scobleizer
@jeffbullas
@briansolis
@tonyrobbins
@kevinrose
@timoreilly
@donttrythis
@zappos
@brainpicker

Twitaholic - A full listing of the top users on Twitter based on Followers. This is a terrific service to find and follow the top users and possibly incorporate some of the ideas they are doing on their account.

Tip: Many of the first few hundred people are celebrities on Twitaholic, if they do not interest you skip the first page.

Create and use lists

Twitter lists are an excellent method of filtering filter through the people you follow. To create a list, click the Lists link and then Create a list. After creating a list visit the persons profile page you wish to add and click the list icon, as shown in the picture to the right. Our Computers and Tech list is an example of a public list we created.

Go Mobile

Apple iPhones, Blackberry phones, Android phones, Windows phone 7 phones, and most of the other smart phones have Twitter applications. Take full advantage of these applications. For users who do not have smart phones Twitter also has extensive support for SMS, which can send tweets over a text message.

Display Twitter RSS feed using PHP

2013-03-22T18:51:00.000-07:00

Most of the bloggers(and developers), have at least once needed to display a twitter feed on their pages. There are a variety of ways of doing that, but today I`ll write about including a twitter feed in your blog using PHP. The code is pretty much straight-forward. The only thing you have to adjust is the amount of tweets you want shown and the username, which feed you`ll be displaying.

<?php

$twitterUsername = "earthquake_jp";

$amountToShow = 5;

$twitterRssFeedUrl = 'https://api.twitter.com/1/statuses/user_timeline.rss?screen_name='.$twitterUsername.'&count='.$amountToShow;

$twitterPosts = false;

$xml = @simplexml_load_file($twitterRssFeedUrl);

if(is_object($xml)){

foreach($xml->channel->item as $twit){

if(is_array($twitterPosts) && count($twitterPosts)==$amountToShow){

break;

}

$d['title'] = stripslashes(htmlentities($twit->title,ENT_QUOTES,'UTF-8'));

$description = stripslashes(htmlentities($twit->description,ENT_QUOTES,'UTF-8'));

if(strtolower(substr($description,0,strlen($twitterUsername))) == strtolower($twitterUsername)){

$description = substr($description,strlen($twitterUsername)+1);

}

$d['description'] = $description;

$d['pubdate'] = strtotime($twit->pubDate);

$d['guid'] = stripslashes(htmlentities($twit->guid,ENT_QUOTES,'UTF-8'));

$d['link'] = stripslashes(htmlentities($twit->link,ENT_QUOTES,'UTF-8'));

$twitterPosts[]=$d;

}

}else{

die('Can`t fetch the feed you requested');

}

?>

<style>

a, a:link, a:visited, a:hover {

 color:#000;

}

.twitter {

 display:table-cell; vertical-align:middle;

 float:left;

 width:250px;

}

</style>

<!-- Insert your html here -->

<div class="twitter" id="jstweets">

 <?php

 if(is_array($twitterPosts)){

 echo '';

 foreach($twitterPosts as $post){

$data = $post['description'];

echo '<a href="{$post['link']}">'.$data."<br >Updated on: ".date('l jS of F Y h:i:s A',$post['pubdate']).'</a><br ><br >';

 }

 echo '';

 }else{

 echo 'No Twitter posts have been made';//Error message

 }

 ?>

</div>

Swing: User Interfaces in Java

2013-02-18T16:07:00.001-08:00

Swing: User Interfaces in Java

Java has a fairly rich framework for creating user interfaces "out of the box". That framework is called Swing. Before learning Swing, it's worth making sure that you really understand the following:

the basic concepts of object-oriented programming (e.g. the notion of classes, object creation, inheritance);
basic Java syntax: how to call methods, how to create loops etc;
interfaces, in the programming sense.

Why am I being so insistent? Essentially, because the Swing framework is highly object-oriented. It contains various classes that extend one another, and the notion of extending a base class to add required functionality to that class is key to user interface programming in Java (and indeed in other languages). Another key part of Swing programming is the notion of listeners: classes or components that "listen out for" a particular event happening such as a button being clicked. And listeners are generally implemented as Java interfaces (in the programming sense), so they're also an important notion to understand. We'll give a brief review of interfaces as we go along, but it helps if you've come across them before.

Introduction to the Swing and user interface packages

Many of the Swing classes representing windows, lists, buttons etc live in the javax.swing package and subpackages. The names of most Swing classes start with the letter J: JFrame, JPanel, JButton, JList etc. In general, if you're looking for the class that represents some visual component in Swing, its name will start with J.
A few classes also live in the java.awt package and subpackages. AWT stands for Abstract Window Toolkit and was in some sense the precursor to Swing. AWT provides a bare-bones way of creating a user interface, based directly on "native" user interface components of the operating system. Swing actually builds on AWT, and some AWT classes are still used directly in Swing programming. For example, many of the classes responsible for laying out user interface components lie inside the java.awt package, and many classes to do with handling events live in java.awt.event; the Graphics interface, which represents a graphics context and is key to rendering graphics inside a window or component, is also originally part of the AWT package.

Example: a first Swing application

By way of a vary basic example which we will extent on the next page, the following application displays a window:

import javax.swing.JFrame;

public class MyApp {
  public static void main(String[] args) {
    // Actually slightly incorrect from a threading point of view
    JFrame frame = new JFrame("My Swing app");
    frame.setSize(500, 500);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);
  }
}

The lines that arguably do most of the work are the ones in bold which construct the window, specifically an instance of JFrame, and then make it visible. We mentioned that user interface components are generally represented by classes inside the javax.swing package with names beginning with J. In this case, a "window with decorations" is strictly speaking called a frame, and represented by the JFrame class. So creating a window means creating an instance of JFrame. We construct one just like most Java objects: by calling its constructor. Note that, as with many constructors, most allow us to specify some common parameters: in this case, the title of the window.
The call to set the size of the window is hopefully self-explanatory once you see it; let us just comment for now that in general, you need to think about the size (and potentially layout) of all windows/components when you're programming with Swing. The call to setDefaultCloseOperation() is a shortcut we can use in the very simple case where we want our application to exit when the window is closed: Swing will dutifully call System.exit() for us. We'll see later that we can customise what happens when a window is closed.

Understanding HTTP Web Proxy Caching

2013-01-31T14:04:00.002-08:00

Internet users direct their requests to web servers all over the Internet. A caching server must act as a web proxy server so it can serve those requests. After a web proxy server receives requests for web objects, it either serves the requests or forwards them to the origin server (the web server that contains the original copy of the requested information). The Traffic Server proxy supports explicit proxy caching, in which the user's client software must be configured to send requests directly to the Traffic Server proxy. The following overview illustrates how Traffic Server serves a request.

Traffic Server receives a client request for a web object.
Using the object address, Traffic Server tries to locate the requested object in its object database (cache).
If the object is in the cache, then Traffic Server checks to see if the object is fresh enough to serve. If it is fresh, then Traffic Server serves it to the client as a cache hit (see the figure below).
If the data in the cache is stale, then Traffic Server connects to the origin server and checks if the object is still fresh (a revalidation). If it is, then Traffic Server immediately sends the cached copy to the client.
If the object is not in the cache (a cache miss) or if the server indicates the cached copy is no longer valid, then Traffic Server obtains the object from the origin server. The object is then simultaneously streamed to the client and the Traffic Server local cache (see the figure below). Subsequent requests for the object can be served faster because the object is retrieved directly from cache.

Caching is typically more complex than the preceding overview suggests. In particular, the overview does not discuss how Traffic Server ensures freshness, serves correct HTTP alternates, and treats requests for objects that cannot/should not be cached. The following sections discuss these issues in greater detail.

Ensuring Cached Object Freshness

When Traffic Server receives a request for a web object, it first tries to locate the requested object in its cache. If the object is in cache, then Traffic Server checks to see if the object is fresh enough to serve. For HTTP objects, Traffic Server supports optional author-specified expiration dates. Traffic Server adheres to these expiration dates; otherwise, it picks an expiration date based on how frequently the object is changing and on administrator-chosen freshness guidelines. Objects can also be revalidated by checking with the origin server to see if an object is still fresh.

HTTP Object Freshness

Traffic Server determines whether an HTTP object in the cache is fresh by:

Checking the Expires or max-age header
Some HTTP objects contain Expires headers or max-age headers that explicitly define how long the object can be cached. Traffic Server compares the current time with the expiration time to determine if the object is still fresh.
Checking the Last-Modified / Date header
If an HTTP object has no Expires header or max-age header, then Traffic Server can calculate a freshness limit using the following formula:
```
freshness_limit = ( date - last_modified ) * 0.10
```
where date is the date in the object's server response header and last_modified is the date in the Last-Modified header. If there is no Last-Modified header, then Traffic Server uses the date the object was written to cache. The value 0.10 (10 percent) can be increased or reduced to better suit your needs (refer to Modifying the Aging Factor for Freshness Computations).

The computed freshness limit is bound by a minimum and maximum value - refer to Setting an Absolute Freshness Limit for more information.
Checking the absolute freshness limit
For HTTP objects that do not have Expires headers or do not have both Last-Modified and Date headers, Traffic Server uses a maximum and minimum freshness limit (refer to Setting an Absolute Freshness Limit).
Checking revalidate rules in the cache.config file
Revalidate rules apply freshness limits to specific HTTP objects. You can set freshness limits for objects originating from particular domains or IP addresses, objects with URLs that contain specified regular expressions, objects requested by particular clients, and so on (refer to cache.config).

Modifying Aging Factor for Freshness Computations

If an object does not contain any expiration information, then Traffic Server can estimate its freshness from the Last-Modified and Date headers. By default, Traffic Server stores an object for 10% of the time that elapsed since it last changed. You can increase or reduce the percentage according to your needs.
To modify the aging factor for freshness computations

Edit the following variables in records.config
- proxy.config.http.cache.heuristic_lm_factor
Run the traffic_line -x command to apply the configuration changes.

Setting absolute Freshness Limits

Some objects do not have Expires headers or do not have both Last-Modified and Date headers. To control how long these objects are considered fresh in the cache, specify an absolute freshness limit.
To specify an absolute freshness limit

Edit the following variables in records.config
- proxy.config.http.cache.heuristic_min_lifetime
- proxy.config.http.cache.heuristic_max_lifetime
Run the traffic_line -x command to apply the configuration changes.

Specifying Header Requirements

To further ensure freshness of the objects in the cache, configure Traffic Server to cache only objects with specific headers. By default, Traffic Server caches all objects (including objects with no headers); you should change the default setting only for specialized proxy situations. If you configure Traffic Server to cache only HTTP objects with Expires or max-age headers, then the cache hit rate will be noticeably reduced (since very few objects will have explicit expiration information).
To configure Traffic Server to cache objects with specific headers

Edit the following variable in records.config
- proxy.config.http.cache.required_headers
Run the traffic_line -x command to apply the configuration changes.

Cache-Control Headers

Even though an object might be fresh in the cache, clients or servers often impose their own constraints that preclude retrieval of the object from the cache. For example, a client might request that a object not be retrieved from a cache, or if it does, then it cannot have been cached for more than 10 minutes. Traffic Server bases the servability of a cached object on Cache-Control headers that appear in both client requests and server responses. The following Cache-Control headers affect whether objects are served from cache:

The no-cache header, sent by clients, tells Traffic Server that it should not to serve any objects directly from the cache; therefore, Traffic Server will always obtain the object from the origin server. You can configure Traffic Server to ignore client no-cache headers - refer to Configuring Traffic Server to Ignore Client no-cache Headers for more information.
The max-age header, sent by servers, is compared to the object age. If the age is less than max-age, then the object is fresh and can be served.
The min-fresh header, sent by clients, is an acceptable freshness tolerance. This means that the client wants the object to be at least this fresh. Unless a cached object remains fresh at least this long in the future, it is revalidated.
The max-stale header, sent by clients, permits Traffic Server to serve stale objects provided they are not too old. Some browsers might be willing to take slightly stale objects in exchange for improved performance, especially during periods of poor Internet availability.

Traffic Server applies Cache-Control servability criteria after HTTP freshness criteria. For example, an object might be considered fresh but will not be served if its age is greater than its max-age.

Revalidating HTTP Objects

When a client requests an HTTP object that is stale in the cache, Traffic Server revalidates the object. A revalidation is a query to the origin server to check if the object is unchanged. The result of a revalidation is one of the following:

If the object is still fresh, then Traffic Server resets its freshness limit and serves the object.
If a new copy of the object is available, then Traffic Server caches the new object (thereby replacing the stale copy) and simultaneously serves the object to the client.
If the object no longer exists on the origin server, then Traffic Server does not serve the cached copy.
If the origin server does not respond to the revalidation query, then Traffic Server serves the stale object along with a 111 Revalidation Failed warning.

By default, Traffic Server revalidates a requested HTTP object in the cache if it considers the object to be stale. Traffic Server evaluates object freshness as described in HTTP Object Freshness. You can reconfigure how Traffic Server evaluates freshness by selecting one of the following options:

Traffic Server considers all HTTP objects in the cache to be stale: always revalidate HTTP objects in the cache with the origin server.
Traffic Server considers all HTTP objects in the cache to be fresh: never revalidate HTTP objects in the cache with the origin server.
Traffic Server considers all HTTP objects without Expires or Cache-control headers to be stale: revalidate all HTTP objects without Expires or Cache-Control headers.

To configure how Traffic Server revalidates objects in the cache, you can set specific revalidation rules in cache.config.
To configure revalidation options

Edit the following variable in records.config
- proxy.config.http.cache.when_to_revalidate
Run the traffic_line -x command to apply the configuration changes.

Scheduling Updates to Local Cache Content

To further increase performance and to ensure that HTTP objects are fresh in the cache, you can use the Scheduled Update option. This configures Traffic Server to load specific objects into the cache at scheduled times. You might find this especially beneficial in a reverse proxy setup, where you can preload content you anticipate will be in demand.
To use the Scheduled Update option, you must perform the following tasks.

Specify the list of URLs that contain the objects you want to schedule for update,
the time the update should take place,
and the recursion depth for the URL.
Enable the scheduled update option and configure optional retry settings.

Traffic Server uses the information you specify to determine URLs for which it is responsible. For each URL, Traffic Server derives all recursive URLs (if applicable) and then generates a unique URL list. Using this list, Traffic Server initiates an HTTP GET for each unaccessed URL. It ensures that it remains within the user-defined limits for HTTP concurrency at any given time. The system logs the completion of all HTTP GET operations so you can monitor the performance of this feature.
Traffic Server also provides a Force Immediate Update option that enables you to update URLs immediately without waiting for the specified update time to occur. You can use this option to test your scheduled update configuration (refer to Forcing an Immediate Update).

Configuring the Scheduled Update Option

To configure the scheduled update option

Edit update.config to enter a line in the file for each URL you want to update.
Edit the following variables in records.config
Run the traffic_line -x command to apply the configuration changes.

Forcing an Immediate Update

Traffic Server provides a Force Immediate Update option that enables you to immediately verify the URLs listed in the update.config file. The Force Immediate Update option disregards the offset hour and interval set in the update.config file and immediately updates the URLs listed.
To configure the Force Immediate Update option

Edit the following variables in records.config
- proxy.config.update.force
- Make sure the variable proxy.config.update.enabled is set to 1.
Run the command traffic_line -x to apply the configuration changes.

IMPORTANT: When you enable the Force Immediate Update option, Traffic Server continually updates the URLs specified in the update.config file until you disable the option. To disable the Force Immediate Update option, set the variable proxy.config.update.force to 0 (zero).

Pushing Content into the Cache

Traffic Server supports the HTTP PUSH method of content delivery. Using HTTP PUSH, you can deliver content directly into the cache without client requests.

Configuring Traffic Server for PUSH Requests

Before you can deliver content into your cache using HTTP PUSH, you must configure Traffic Server to accept PUSH requests.
To configure Traffic Server to accept PUSH requests

Edit records.config, modify the super mask to allow PUSH request.
- proxy.config.http.quick_filter.mask
Edit the following variable in records.config, enable the push_method.
- proxy.config.http.push_method_enabled
Run the command traffic_line -x to apply the configuration changes.

Understanding HTTP PUSH

PUSH uses the HTTP 1.1 message format. The body of a PUSH request contains the response header and response body that you want to place in the cache. The following is an example of a PUSH request:

PUSH http://www.company.com HTTP/1.0
Content-length: 84

HTTP/1.0 200 OK
Content-type: text/html
Content-length: 17

<HTML>
a
</HTML>

IMPORTANT: Your header must include Content-length - Content-length must include both header and body byte count.

Tools that will help manage pushing

There is a perl script for pushing, tools/push.pl, which can help you understanding how to write some script for pushing content.

Pinning Content in the Cache

The Cache Pinning Option configures Traffic Server to keep certain HTTP objects in the cache for a specified time. You can use this option to ensure that the most popular objects are in cache when needed and to prevent Traffic Server from deleting important objects. Traffic Server observes Cache-Control headers and pins an object in the cache only if it is indeed cacheable.
To set cache pinning rules

Make sure the following variable in records.config is set
- proxy.config.cache.permit.pinning
Add a rule in cache.config for each URL you want Traffic Server to pin in the cache. For example:
```
url_regex=^https?://(www.)?apache.org/dev/ pin-in-cache=12h
```
Run the command traffic_line -x to apply the configuration changes.

To Cache or Not to Cache?

When Traffic Server receives a request for a web object that is not in the cache, it retrieves the object from the origin server and serves it to the client. At the same time, Traffic Server checks if the object is cacheable before storing it in its cache to serve future requests.

Caching HTTP Objects

Traffic Server responds to caching directives from clients and origin servers, as well as directives you specify through configuration options and files.

Client Directives

By default, Traffic Server does not cache objects with the following request headers:

Authorization: header
Cache-Control: no-store header
Cache-Control: no-cache header
To configure Traffic Server to ignore the Cache-Control: no-cache header, refer to Configuring Traffic Server to Ignore Client no-cache Headers.
Cookie: header (for text objects)
By default, Traffic Server caches objects served in response to requests that contain cookies (unless the object is text). You can configure Traffic Server to not cache cookied content of any type, cache all cookied content, or cache cookied content that is of image type only. For more information, refer to Caching Cookied Objects.

Configuring Traffic Server to Ignore Client no-cache Headers

By default, Traffic Server strictly observes client Cache-Control: no-cache directives. If a requested object contains a no-cache header, then Traffic Server forwards the request to the origin server even if it has a fresh copy in cache. You can configure Traffic Server to ignore client no-cache directives such that it ignores no-cache headers from client requests and serves the object from its cache.
To configure Traffic Server to ignore client no-cache headers

Edit the following variable in records.config
- proxy.config.cache.ignore_client_no_cache
Run the command traffic_line -x to apply the configuration changes.

Origin Server Directives

By default, Traffic Server does not cache objects with the following response headers:

Cache-Control: no-store header
Cache-Control: private header
WWW-Authenticate: header
To configure Traffic Server to ignoreWWW-Authenticate headers, refer to Configuring Traffic Server to Ignore WWW-Authenticate Headers.
Set-Cookie: header
Cache-Control: no-cache headers
To configure Traffic Server to ignore no-cache headers, refer to Configuring Traffic Server to Ignore Server no-cache Headers.
Expires: header with value of 0 (zero) or a past date

Configuring Traffic Server to Ignore Server no-cache Headers

By default, Traffic Server strictly observes Cache-Control: no-cache directives. A response from an origin server with a no-cache header is not stored in the cache and any previous copy of the object in the cache is removed. If you configure Traffic Server to ignore no-cache headers, then Traffic Server also ignores no-store headers. The default behavior of observing no-cache directives is appropriate in most cases.
To configure Traffic Server to ignore server no-cache headers

Edit the following variable in records.config
- proxy.config.cache.ignore_server_no_cache
Run the command traffic_line -x to apply the configuration changes.

Configuring Traffic Server to Ignore WWW-Authenticate Headers

By default, Traffic Server does not cache objects that contain WWW-Authenticate response headers. The WWW-Authenticate header contains authentication parameters the client uses when preparing the authentication challenge response to an origin server.
When you configure Traffic Server to ignore origin server WWW-Authenticate headers, all objects with WWW-Authenticate headers are stored in the cache for future requests. However, the default behavior of not caching objects with WWW-Authenticate headers is appropriate in most cases. Only configure Traffic Server to ignore server WWW-Authenticate headers if you are knowledgeable about HTTP 1.1.
To configure Traffic Server to ignore server WWW-Authenticate headers

Edit the following variable in records.config
- proxy.config.cache.ignore_authentication
Run the command traffic_line -x to apply the configuration changes.

Configuration Directives

In addition to client and origin server directives, Traffic Server responds to directives you specify through configuration options and files.
You can configure Traffic Server to do the following:

Not cache any HTTP objects (refer to Disabling HTTP Object Caching).
Cache dynamic content - that is, objects with URLs that end in .asp or contain a question mark (?), semicolon (;), or cgi. For more information, refer to Caching Dynamic Content.
Cache objects served in response to the Cookie: header (refer to Caching Cookied Objects).
Observe never-cache rules in the cache.config file.

Disabling HTTP Object Caching

By default, Traffic Server caches all HTTP objects except those for which you have set never-cache rules in the cache.config file. You can disable HTTP object caching so that all HTTP objects are served directly from the origin server and never cached, as detailed below.
To disable HTTP object caching manually

Edit the following variable in records.config
- proxy.config.cache.http
Run the command traffic_line -x to apply the configuration changes.

Caching Dynamic Content

A URL is considered dynamic if it ends in .asp or contains a question mark (?), a semicolon (;), or cgi. By default, Traffic Server caches dynamic content. You can configure the system to ignore dyanamic looking content, although this is recommended only if the content is truely dyanamic, but fails to advertise so with appropriate Cache-Control headers.
To configure Traffic Server's cache behaviour in regard to dynamic content

Edit the following variable in records.config
- proxy.config.http.cache.cache_urls_that_look_dynamic
Run the command traffic_line -x to apply the configuration changes.

Caching Cookied Objects

By default, Traffic Server caches objects served in response to requests that contain cookies. This is true for all types of objects except for text. Traffic Server does not cache cookied text content because object headers are stored along with the object, and personalized cookie header values could be saved with the object. With non-text objects, it is unlikely that personalized headers are delivered or used.
You can reconfigure Traffic Server to:

Not cache cookied content of any type.
Cache cookied content that is of image type only.
Cache all cookied content regardless of type.

To configure how Traffic Server caches cookied content

Edit the following variable in records.config
- proxy.config.cache_responses_to_cookies
Run the command traffic_line -x to apply the configuration changes.

Forcing Object Caching

You can force Traffic Server to cache specific URLs (including dynamic URLs) for a specified duration, regardless of Cache-Control response headers.
To force document caching

Add a rule for each URL you want Traffic Server to pin to the cache cache.config:
```
url_regex=^https?://(www.)?apache.org/dev/ ttl-in-cache=6h
```
Run the command traffic_line -x to apply the configuration changes.

Caching HTTP Alternates

Some origin servers answer requests to the same URL with a variety of objects. The content of these objects can vary widely, according to whether a server delivers content for different languages, targets different browsers with different presentation styles, or provides different document formats (HTML, XML). Different versions of the same object are termed alternates and are cached by Traffic Server based on Vary response headers. You can specify additional request and response headers for specific Content-Types that Traffic Server will identify as alternates for caching. You can also limit the number of alternate versions of an object allowed in the cache.

Configuring How Traffic Server Caches Alternates

To configure how Traffic Server caches alternates, follow the steps below

Edit the following variables in records.config
Run the command traffic_line -x to apply the configuration changes.

Note: If you specify Cookie as the header field on which to vary in the above variables, make sure that the variable proxy.config.cache.cache_responses_to_cookies is set appropriately.

Limiting the Number of Alternates for an Object

You can limit the number of alternates Traffic Server can cache per object (the default is 3).
IMPORTANT: Large numbers of alternates can affect Traffic Server cache performance because all alternates have the same URL. Although Traffic Server can look up the URL in the index very quickly, it must scan sequentially through available alternates in the object store.
To limit the number of alternates

Edit the following variable in records.config
- proxy.config.cache.limits.http.max_alts
Run the command traffic_line -x to apply the configuration changes.

Using Congestion Control

The Congestion Control option enables you to configure Traffic Server to stop forwarding HTTP requests to origin servers when they become congested. Traffic Server then sends the client a message to retry the congested origin server later.
To use the Congestion Control option, you must perform the following tasks:

Set the following variable in records.config
- proxy.config.http.congestion_control.enabled to 1
Create rules in the congestion.config file to specify:
which origin servers Traffic Server tracks for congestion
the timeouts Traffic Server uses, depending on whether a server is congested
the page Traffic Server sends to the client when a server becomes congested
if Traffic Server tracks the origin servers per IP address or per hostname
Run the command traffic_line -x to apply the configuration changes.

Microsoft Word 2010 Tips And Tricks

2013-01-31T12:39:00.002-08:00

Microsoft Word 2010 is one of our favorite text editors. With such a big array of features, Microsoft Office Word 2010 can look complicated. There are many hidden tricks and shortcuts that make text editing easier. Here are some tips I think will help you when you are using Microsoft Word 2010.

Microsoft Word 2010 Tips And Tricks

1. Vertical Selection Of Text
Normally, we select a character, a word, a sentence or a paragraph. All these selections are horizontal selections. Sometimes you may need to select vertically. For example, if your text has numbers in the beginning, you may want to select only the numbers to delete them at one go (see figure).

To select text horizontally, press ALT and click to drag and make a selection. Remember to release ALT key before releasing mouse else it will open the Research dialog. Check out the different uses of vertical selections and let us know what all you did with this feature.
2. Default Line Spacing
The default line spacing in Microsoft Word 2010 is 1.15 against 1 in Microsoft Word 2003. Microsoft changed the line spacing to make your text more readable. If you want the default line spacing as 1, follow this procedure:

While on the Home tab, right click on the Normal quick style button and select Modify
In the Format list that appears, select Paragraph
Under spacing, change the line spacing from 1.15 to 1
Click OK
Check the box against “New documents based on this template”
Click OK

3. Changing The Default Save Location
By default, MS Word opens Documents folder when you press CTRL+S for first time. If you think this is irritating you, you can change the default file location to some other place where you normally store your documents.

Click on File
Click on Options
Click Advanced in the left side of the window that appears
In the right part of the window, scroll down to the button that says “File Locations”
Select Documents and click on Modify
In the Save File dialog box that appears, enter or select the new path and click on OK to close the Save File dialog box.
Click OK to close the window.

4. Change Default Font
The default font for new documents in MS Word 2010 is Calibri. Though the font is good for online viewing, it creates problems when printing. You may be using Times New Roman or Arial for print jobs. One method is to change the font manually each time after you have typed the document. But then, it would involve formatting the document again. Another method is to change the default font.

Right click on the Normal quick style button on Home tab.
Click Modify
In the dialog box that appears, click on Format… to open the drop down menu and select Font
In the Font dialog box, select the font you wish to use with every document.
Make any other changes you wish such as font size etc
Click OK
Click to select “New documents based on this template”
Click OK to close the Modify dialog box.

5. Move Rows Of Text In Table
Sometimes when you are working on the table, you may want to move one or more rows in the table up or down without having to change the table formatting. One method is copy pasting but that risks formatting.
Another method is using ALT+SHIFT+UP arrow key to move entire row up. Similarly, to move the entire row down, use ALT+SHIFT+DN arrow key. Note that you have to select the row before you can move it using the ALT+SHIFT+Arrow keys. This method makes sure the formatting is not disturbed.
6. Quickly Change Line Spacing
Sometimes need arises that you have to change line spacing among different paragraphs. Here are the shortcut keys:
CTRL + 1 –> Change line spacing to 1
CTRL + 2 –> Change line spacing to 2
CTRL + 5 –> Change line spacing to 1.5
Note that you just need to place the cursor on the paragraph that needs to be styled. You need not select the paragraph.
7. Quickly Adding Borders to Paragraphs
If you wish to add borders to some paragraph, you can use the Borders and Shading dialog box. However, if your need is just to add bottom border to text/paragraph, you can do it by adding three special characters and hitting Enter.
Press – (hyphen) three times and press Enter to draw an underline border of 3/4 points
Press _ (underscore) three times and press Enter to draw an underline border of 1.5 points
Press ~ (tilde) three times and press Enter to draw a zigzag underline border
Press * (asterisk) three times and press Enter to draw a dotted underline border
Press = (equal to) three times and press Enter to draw a double underline border
8. Find Special Formatting
You can find text that is specially formatted. For example, you can find highlighted text or text whose font is Times New Roman. You can also search for bold text or italics. There are many more options when you use the Find option.

Press CTRL+F to open the Find pane. In Word 2010 it appears to the left side of the window.
Click on the down facing triangle next to magnifying glass and click on Advanced Find…
In the Find dialog box that appears, click on More.
You can see plenty of options under Format.
When you select anything, it appears under the “Find What” textbox. When you click Find Next without entering anything in the “Find What” text box, it searches for the format you have selected. For example, you can select Font and in the Font dialog box, select a font and its properties (bold, italics etc).

9. Merging Formatting When Pasting Across Documents
When you copy anything from another document and paste it in the current document, you will want the copied text to match the formatting of the current document. While you can manually format each time you copy text from other documents to the current one, you can also set the default paste to merge formatting so that the text copied from other sources acquires formatting of current document.

To set the default formatting, click on the down facing triangle below Paste on Home tab
Click Set Default Paste
In the window that appears, Select Merge Destinations in: 1: When Pasting in Same Document and 2: When Pasting between Documents.
Click OK to close the window

10. Copy Only Formatting
Sometimes you may want to apply an already existing formatting from one part of your document to another part. You have the Format Painter for the purpose. Using the Format Painter can be irritating when dealing with long documents. Here is another method that is easier to use.
Press CTRL+SHIFT+C instead of CTRL+C. This will copy only the formatting and leave the text.
Move to the destination where the formatting is to be applied. Select the text to which formatting is to be applied. Press CTRL+SHIFT+V to paste the formatting to the selection.
Above are some Microsoft Word 2010 tips and tricks that make your working on the editor easy. If you have anything to share, please use the comments section.

10 cool Microsoft Word tips and tricks

2013-01-31T12:28:00.004-08:00

If you are a Word power-user, then these tips may well help you get more done

Despite the many alternatives that are out there, Microsoft Word remains one of the most popular word processors available.
However, most of us barely scratch the surface of its abilities.
With this selection of Microsoft Word tips, you can really step up your game, no matter which version you use, and you'll be able to work more efficiently than ever before.
1. Configure paste options
Word tries to be helpful when copied text is pasted into a document by automatically retaining the source formatting, while providing the option to change the text to match the formatting of the current document.

To avoid having to choose formatting options every time text is pasted, click the 'Office' button, followed by 'Word Options', then move to the 'Advanced' section. Under the 'Cut, copy and paste' heading, use the first four dropdown menus to choose a default setting for format pasting.
While configuring these options, untick the box labelled 'Show Paste Options Buttons' to prevent the formatting options pop-up from being displayed in the future.
2. Change full-justification formatting
When full justification is applied to a paragraph, Word ensures that text is vertically aligned on the left and right of the page by adjusting the spacing between words. While this usually isn't a problem, there are occasions when it can lead to a lot of visible white space.
By opting to use the justification style that's utilised in WordPerfect, the spacing between individual letters on each line is adjusted to allow for better-looking text when it spans from margin to margin.
To activate this option, click the 'Office' button, followed by 'Word Options', and then click the 'Advanced' link on the left. Scroll to the bottom of the advanced options and expand the 'Layout Options' entry. Now you just need to tick the box labelled 'Do Full Justification The Way WordPerfect 6.x For Windows Does', then click 'OK'.
3. Use a hanging indent
One of the less frequently used means of formatting paragraphs is the hanging indent. This is where the first line is not indented, but all of the rest are.

Select the paragraph you'd like to format in this way, move to the Home tab and double-click the arrow icon in the lower right-hand corner of the 'Paragraph' pane.
On the Indents and Spacing tab, use the 'Special' dropdown menu in the middle of the dialog to select the 'Hanging' option and then indicate the indentation level. To apply the indent, click 'OK'.
4. Show and hide the ribbon
For many people, the ribbon interface used in Office 2007 is a great step forward, while others find it somewhat overwhelming. If you fall into the latter category, you'll be happy to know that the ribbon can be temporarily hidden to provide you with a larger working area and clear away the clutter.
It's also worth noting that the ribbon can quite easily be hidden by accident, so if this has happened, these tips can be used to show and hide it as required.
The first option is to click the down arrow icon at the end of the Quick Access Toolbar and tick or untick the 'Minimize the Ribbon' option. This menu can also be accessed by right-clicking anywhere on the ribbon.
The third option is to double-click one of the tabs at the top of the ribbon to toggle the ribbon on and off. Finally, you can always use the keyboard shortcut – simply press [Ctrl]+[F1].
5. Number pages
It's easy to configure a header and footer for your Word document so the page number is displayed on every page. In many instances, though, a document will have a title page for which a number is not required.

Set up page numbering as required and then in Word 2007 and 2010, move to the Page Layout tab before clicking the button in the lower right-hand corner. Switch to the Layout tab and tick the box labelled 'Different first page', before clicking OK.
6. Back up the Quick Access Toolbar
If you've spent a great deal of time customising the Quick Access Toolbar (QAT), it's all too easy to forget about it if you ever need to reinstall Windows. Thankfully, you can create a backup of the toolbar, which means it can be brought back without any hassle, or copied to other machines that you work with.
In Windows XP, use Explorer to navigate to 'C:\Documents and Settings\[username]\Local Settings\Application Data\ Microsoft\Office', while in Windows Vista or 7, you should head to 'C:\Users\[username]\ AppData\Local\Microsoft\ Office'.
Here you'll find a file called 'Word.qat' – this can be duplicated for backup purposes, or copied to another computer.
7. Remove formatting
If text has been formatted and you change your mind about how it should appear, click the word in question, or select a section of text, and press [Ctrl]+[Space] simultaneously. If the formatting has been applied with a style, press [Ctrl]+[Shift]+[N] and it will then revert to the default style.
8. Adjust font spacing in headings
Text space can be adjusted to help ensure that a heading fits on a single line, rather than wrapping onto a second, or expanded to reduce the amount of white space in a line.
Select a line of text, right click and select Font from the context menu. Letter widths can be adjusted by selecting a new size from the Scale dropdown menu, but it's also possible to adjust spacing. Use the up and down arrows in the Spacing section to expand or compress it.
9. Compare documents
There are various reasons why you might want to compare two documents and Word provides the option to open two files side by side for this very purpose. However, if you're using a monitor in portrait mode, side-by-side document comparison is less useful than having one document displayed above the other.

Thankfully, this arrangement option is available. In Word 2003 and older, open the two documents you want to compare, click the 'Window' menu and select 'Compare Side by Side'. Now click the 'Window' menu again and select the 'Arrange All' option.
In Word 2007 and 2010, open the documents that you want to compare and move to the View tab of the ribbon. Click the 'View Side by Side' button, and then click 'Arrange All'. Press 'Synchronous Scrolling' and you can scroll then through both of your documents at the same time.
10. Paste text with the Spike
While the clipboard provides a useful way to copy and move text around a Word document, there's a little-known feature called the Spike that provides an alternative. Text that's added to the Spike is cut from the document and there's no limit to the number of entries that can be added.

When the content of the Spike is pasted into a document, it's done so in the order that it was spiked. This provides a very handy way of reorganising paragraphs or lists, without the need for endless cutting and pasting.
To add text to the Spike, select it and press [Ctrl]+[F3] simultaneously – this can be repeated as many times as required. To paste the contents of the Spike back into a document, you just need to press [Ctrl]+[Shift]+[F3].
This will clear the Spike, ready to start collecting more data, but it's also possible to paste the Spike while retaining its contents for future use. Position the cursor where the pasted text should appear, type the word spike and then press [F3].

Mot de passe oublié

2013-01-31T12:21:00.001-08:00

Vous pouvez créer sous Windows XP une disquette de réinitialisation de mot de passe. Cette disquette a pour but de vous empêcher d'oublier votre mot de passe. Pour créer cette disquette, rendez-vous dans le panneau de configuration et cliquez sur Comptes utilisateurs. Cliquez sur le compte pour lequel vous souhaitez créer une disquette et cliquez à gauche sur Empêcher un mot de passe oublié. L'assistant s'affiche :

Cliquez sur suivant et insérez une disquette vierge et formatée dans le lecteur A.

Cliquez ensuite sur suivant. Indiquez ensuite votre mot de passe actuel, et cliquez sur suivant

L'assistant réalise la disquette. Cliquez sur suivant une fois la réalisation terminée..

Cliquez ensuite sur suivant pour terminer la réalisation de la disquette.

Ensuite si vous oubliez votre mot de passe, voici la méthode pour accéder à votre ordinateur :

Si votre ordinateur ne fait pas partie d'un domaine ou d'un environnement de domaine (c'est généralement le cas) :

Lorsque l'écran d'ouverture de session s'affiche, sélectionnez votre nom d'utilisateur puis tapez votre mot de passe. Une petite boîte intitulée Avez-vous oublié votre mot de passe ? s'affiche.
Cliquez sur utiliser votre disque de réinitialisation de mot de passe pour lancer l'Assistant. Suivez les instructions de l'Assistant qui créera un nouveau mot de passe. Vous pourrez ensuite ouvrir une session en utilisant le nouveau mot de passe. Gardez votre disquette de récupération de mot de passe pour en recréer autant que vous souhaitez, il n'est pas nécessaire de recréer la disquette.

Les instructions suivantes s'appliquent uniquement dans le cas d'un environnement de domaine ou d'un ordinateur qui a fait partie d'un domaine.

Lorsque l'écran d'ouverture de session s'affiche, appuyez sur CTRL+ALT+SUPPR et tapez votre mot de passe dans la zone Mot de passe. Une boîte de dialogue Échec de l'ouverture de session s'affiche. Cliquez sur Réinitialiser et insérez la disquette de réinitialisation de mot de passe. Suivez les instructions de l'Assistant qui créera un nouveau mot de passe. Ouvrez une session en utilisant le nouveau mot de passe, puis rangez la disquette de réinitialisation des mots de passe dans un endroit sûr en vue d'une utilisation ultérieure. Il n'est pas nécessaire de créer une nouvelle disquette.
Pour obtenir des informations générales sur l'Assistant Mot de passe oublié et sur l'Assistant Réinitialisation du mot de passe, et pour prendre connaissance des instructions permettant de créer une disquette de réinitialisation des mots de passe, cliquez sur Rubriques connexes.

Créer une disquette de démarrage [Windows XP]

2013-01-31T12:09:00.003-08:00

Voici l'étape à suivre pour créer une disquette de démarrage qui vous servira à démarrer la console en cas de problème.
Insérez une disquette (qui sera la future disquette de démarrage) dans le lecteur. Allez dans le poste de travail et faites une clic droit sur le lecteur de disquettes. Choisissez "formater".
Vous avez un écran ressemblant à ceci normalement :

Cochez la case "créer une disquette de démarrage MS-DOS" et cliquez sur Ok.
Voilà, votre disquette de démarrage est terminée.

Nettoyer Windows : supprimez tous les programmes et fichiers inutiles

2013-01-31T12:08:00.003-08:00

Windows est très gourmand en espace disque et provoque un désordre dans tout le PC. Pour bénéficier du maximum d'espace sur votre disque dur et accélérer votre PC, il n'est pas inutile de le nettoyer en profondeur.
Voici comment procéder :

(le texte noté en gras et en rouge est à répéter pour tous les lecteurs du poste de travail).

Tout d'abord, rendez vous dans le poste de travail. Sélectionnez le lecteur C: et faites un clic avec le bouton droit de la souris. Cliquez ensuite sur "propriétés". Vous vous retrouvez face à cet écran :

Cliquez sur "nettoyage de disque". Une nouvelle fenêtre apparaît : vous êtes dans l'utilitaire qui permet de nettoyer le disque dur. Cochez toutes les cases qui se trouvent dans le cadre "Fichier à supprimer :" puis cliquez sur ok. Répondez "oui" à la boîte de dialogue qui s'affiche.

Revenez à la fenêtre du nettoyage de disque et cliquez ensuite sur l'onglet "autres options". Ces options sont les plus importantes et permettent de gagner énormément d'espace disque :

Certains composants de Windows sont cachés et ne peuvent être supprimés sans la modification d'un fichier. Cliquez sur "démarrer", puis sur "rechercher" et indiquez dans la zone de recherche le fichier "sysoc.inf". Le fichier se trouve dans le répertoire "C:\windows\inf". Cochez dans les préférences les cases qui permettent de rechercher dans les fichiers cachés et les fichiers système. Une fois ce fichier ouvert (dans le bloc notes), cliquez sur "édition", puis "remplacer". Une nouvelle fenêtre apparaît. Dans la case "Rechercher :", indiquez "hide" et dans la case "Remplacer par :", mettez "*". Cliquez sur remplacer. Les modifications sont apportées au fichier. Cliquez sur "fichier", puis sur "enregistrer". Vous pouvez fermer le bloc notes. Revenez à la fenêtre du nettoyage de disque. Dans la case "Composants Windows", cliquez sur "Nettoyer". Vous vous retrouvez face à cette fenêtre :

Sélectionnez "Accessoires et utilitaires" et cliquez sur "détails". Décochez les composants dont vous n'avez pas besoin. Décochez ensuite les autres accessoires tels que : "MSN explorer", "Service d'indexation", "Windows Messenger".
Cliquez ensuite sur suivant et revenez à la fenêtre du nettoyage de disque. Dans la case "Programmes installés", cliquez sur "nettoyer". L'écran que vous voyez devrait être similaire à celui-ci :

Pour chaque programme que vous n'avez pas besoin, sélectionnez le et cliquez sur "supprimer". Répétez l'opération autant de fois que nécessaire. Revenez à la fenêtre du nettoyage de disque et dans la case "Restauration du système", cliquez sur "Nettoyer". Répondez "oui" à la boîte de dialogue qui s'affiche. Faites ensuite un clic droit sur le bouton démarrer, et cliquez sur "explorer". Rendez vous tout d'abord dans le dossier C:\WINDOWS\Help\Tours. Supprimez tous les fichiers et dossiers résiduels. Un seul dossier restera : mmTour, qui refuse de se supprimer. Rendez vous ensuite au dossier parent, celui nommé Help. Ici se trouvent les fichiers d'aide de Windows, au format .hlp et .chm. Vous pouvez supprimer les fichiers portant cette extension si vous ne vous servez pas de l'aide de vos logiciels, ni de celle de Windows.

Rendez vous ensuite dans le répertoire temporaire en tapant dans la barre d'adresses %temp%. Appuyez sur la touche "Entrée". Ce dossier contient les fichiers normalement utilisés par les applications et supprimés dès qu'il n'y en a plus besoin. En réalité il reste toujours des fichiers dans ce dossier si l'application a planté ou si elle est mal conçue. Cliquez ensuite sur entrée et supprimez tous les dossiers et fichiers. Voilà ! vous devriez avoir normalement gagné plusieurs dizaines de méga octets sur votre disque.

Créer un point de restauration système

2013-01-31T12:07:00.002-08:00

Créer un point de restauration système permet, le cas échéant, de revenir à une configuration telle qu'elle se trouve au jour où le point à été créé.
Nous aurons besoin de l'outil de Windows disponible ici :

Menu démarrer/programmes/accessoires/outils système/restauration système

Voici l'écran d'accueil du programme :

Trois options sont disponibles. Celle qui nous intéresse est 'Créer un point de restauration'. Sélectionnez cette option et cliquez sur suivant.
Une autre page apparaît. Vous devez entrer une description de la restauration. Entrez une description et cliquez sur créer. Un descriptif s'affiche. Cliquez ensuite sur démarrage, puis annuler. Votre point de restauration à été créé. Il vous servira par la suite à restaurer votre système tel qu'il est maintenant.

La mise en forme conditionnelle [Excel]

2013-01-31T12:03:00.001-08:00

La mise en forme conditionnelle va vous permettre de mettre en forme (couleur de fond, changement de police, etc) une ou plusieurs cellules en fonction de conditions que vous définirez. Vous pourrez par exemple colorier en vert toutes les cellules ayant leur valeur supérieure à 10 et en rouge celles ayant une valeur inférieure à 0. Les possibilités sont infinies.
Pour ce tutorial, nous allons reprendre l'exemple du fichier excel que nous avons pris pour le premier tutorial : Créer une macro - Excel.

Notre objectif sera de faire une mise en forme selon la valeur des chiffres de la colonne C. Spécifions des règles (une seule règle peut suffir, mais ici nous allons en spécifier plusieurs de manière à montrer un exemple) :

Si la valeur de la cellule se trouve comprise entre 1 et 45, la cellule deviendra rouge avec une police d'écriture jaune.
Si la valeur de la cellule se trouve comprise entre 46 et 70, la cellule deviendra bleue avec une police d'écriture jaune.
Si la valeur de la cellule se trouve comprise entre 71 et 100, la cellule deviendra verte avec une police d'écriture noire.

Maintenant que les règles sont définies, nous allons les mettre en pratique. Sélectionnez entièrement la colonne C en cliquant dans la liste des colonnes sur la lettre C. Vous vous retrouvez avec un écran de ce style :

Cliquez ensuite sur le menu Format => Mise en forme conditionnelle. Une nouvelle fenêtre apparaît :

Dans le cadre Condition1, prenez l'option La valeur de la cellule est et à droit de cette option choisissez l'option comprise entre. Ensuite dans l’autre case à droite, vous marquez la valeur 1 et dans la dernière case, la valeur 45, ce qui aura pour but d'activer une règle conditionnelle pour les valeurs comprises entre 1 et 45.
Nous allons maintenant spécifier la mise en forme de la cellule. Pour ce faire, cliquez sur le bouton Format :

Dans l'onglet police, vous pouvez choisir la couleur du texte (prenez pour cette règle un jaune assez voyant) ainsi que sa mise en forme générale. Dans l'onglet motifs, vous allez pouvoir modifier l'arrière-plan de la cellule :

Choisissez ici le rouge. Cliquez sur Ok. Cliquez ensuite sur Ajouter pour ajouter une seconde règle conditionnelle :

Vous allez pouvoir maintenant rajouter les deux règles conditionnelles que nous avons établies plus haut (à savoir une cellule bleue avec du texte jaune pour les valeurs comprises entre 46 et 70, ainsi que la dernière règle voulant qu'une cellule ayant sa valeur comprise entre 71 et 100 soit sur fond vert avec du texte noir). Cliquez sur Ajouter une fois que vous aurez complété la deuxième règle, pour pouvoir ajouter la dernière.
Si tout s'est bien passé, vous devriez avoir ce résultat :

Installer apache sous Windows

2013-01-31T11:54:00.000-08:00

Apache est le serveur le plus utilisé au monde. Conçu à l'origine pour les systèmes UNIX, il existe aussi pour windows. Voyons comment l'installer :
Commencez par télécharger Apache ici. Ouvrez ensuite le fichier. Un écran d'accueil s'ouvre :

Cliquez trois fois sur le bouton Next (pour accepter la license et passer la lecture du lisez-moi).
Vous arrivez devant cet écran :

Dans la zone Network Domain indiquez l'adresse IP de votre serveur (en général la machine locale, donc 127.0.0.1). Dans la zone Server Name, indiquez "localhost". Ceci vous permettra d'accéder à votre serveur en tapant ce nom dans votre barre d'adresses d'internet Explorer. Indiquez ensuite un email de contact (vous pouvez mettre n'importe quoi dans cette case).
Sélectionnez ensuite For All Users, on Port 80, as a service -- Recommended, puis cliquez sur le bouton Next.

Sélectionnez l'option Custom, et cliquez sur le bouton Next.

Cliquez sur Apache Documentation de manière à ne pas l'installer. Vous économiserez plus de 30 Mo d'espace disque. Cliquez ensuite sur Apache HTTP Server 2.0.50 puis sur le bouton Change si vous souhaitez changer le répertoire d'installation. Cliquez ensuite sur le bouton Next. Cliquez ensuite sur le bouton Install, puis sur le bouton Finish.
L'installation est terminée !
Rendez-vous dans Internet Explorer, et tapez "http://localhost". Si une page décrivant apache s'affiche, c'est bon ! (vous pouvez alors placer vos fichiers html, zip, etc... dans le dossier htdocs (du répertoire apache2, lui-même situé dans le répertoire d'installation d'apache), sinon recommencez l'installation.

Partager des fichiers sous Windows

2013-01-31T11:51:00.000-08:00

Partager des fichiers sous Windows XP (avec des PC clients sous Windows 98/Me/2000 ou XP) peut vite devenir l'enfer et il arrive souvent de voir des messages "Accès refusé" ou encore "l'utilisateur ne bénéficie pas du type de session demandé sur cet ordinateur" quand ce n'est tout simplement pas une fenêtre qui apparaît avec un mot de passe alors que vous n'en avez jamais défini !
Nous allons donc apprendre ici à paramétrer correctement Windows XP pour qu'il permette un partage de fichiers dans les meilleures conditions, sans messages d'erreurs. La première chose à faire lorsque l'on veut partager des fichiers, est paradoxalement de désactiver le partage de fichiers simple ! Je sais, ce n'est normalement pas logique, mais vous verrez au fur et à mesure de l'utilité d'une telle mesure. Pour désactiver le partage de fichiers simple, allez dans le poste de travail, puis cliquez sur le menu outils => options des dossiers. Cliquez ensuite sur l'onglet Affichage, puis décochez Utiliser le partage de fichiers simple (recommandé). Cliquez ensuite sur Ok.

Une fois ceci fait, il va falloir partager proprement dit les dossiers ou fichiers de votre choix. Nous allons utiliser par défaut le répertoire documents partagés de Windows qui se situe ici : C:\Documents and Settings\All Users\Documents. Il s'agit d'un choix arbitraire, vous pouvez tout à fait utiliser un autre dossier de partage situé n'importe où sur votre disque dur, la procédure sera la même.

Pour que les autres utilisateurs du réseau voient votre dossier partagé, il va falloir lui attribuer des autorisations spéciales. Faites un clic droit sur ce dossier, puis cliquez sur Propriétés, puis sur l'onglet Partage. Vous arrivez devant une fenêtre de ce style :

Sélectionnez la case Partager ce dossier, et attribuez un nom (de préférence faisant moins de 12 caractères, mais bon ce n'est pas une obligation si tous vos postes sont sous XP ou 2000). Il va maintenant falloir attribuer des autorisations d'accès. Cliquez sur le bouton Autorisations. Une fenêtre comme celle-ci s'ouvre alors :

Par défaut les utilisateurs qui accèdent à vos dossiers de partage seront notés comme étant Invité. Il va donc falloir leur permettre d'accéder aux ressources mises à leur disposition. Pour ce faire, cliquez sur Ajouter, puis dans la zone de texte, tapez Invité. Cliquez ensuite sur Ok.

Si tout va bien, vous avez maintenant une fenêtre devant vous qui ressemble à ça :

Sélectionnez le compte "Invité" puis dans la liste des autorisations, vous pouvez maintenant cocher "Lecture" pour que les utilisateurs distants puissent voir vos fichiers, ainsi que "Modification" si vous souhaitez qu'ils puissent supprimer ou écraser vos fichiers. Une fois ceci fait, cliquez sur Ok, puis sur l'onglet "Sécurité". Il va maintenant falloir réitérer les mêmes opérations (cliquer sur Ajouter, taper "Invité", cliquer sur ok puis attribuer des droits).

Une fois tout ceci fait, cliquez sur Ok. Le dossier apparaît désormais avec une main en dessous, signifiant qu'il est partagé. Dans le meilleur des mondes, il nous aurait fallu nous arrêter maintenant pour que tout fonctionne. Oui, mais malheureusement, les messages d'erreurs d'impossibilité d'accès seront présents si on s'arrête là. Il va donc falloir aller dans les méandres de Windows pour aller rajouter des autorisations d'accès via le réseau pour les utilisateurs identifiés comme "Invité". Pour ce faire, il va falloir aller dans la stratégie de groupe de Windows. Cliquez sur démarrer => panneau de configuration => outils d'administration => stratégie de sécurité locale. Déroulez à gauche Stratégies locales, puis cliquez sur Attribution des droits utilisateur. Vous arrivez devant une fenêtre de ce style :

L'option qui nous intéresse est la première, intitulée Accéder à cet ordinateur depuis le réseau. Double-cliquez dessus. Vous arrivez devant une fenêtre de ce style :

Si la mention "Invité" n'apparaît pas, cliquez sur Ajouter un utilisateur ou un groupe. Cliquez sur Avancé puis sur Rechercher. Sélectionnez ensuite Invité puis cliquez deux fois sur Ok. Vérifiez que l'option "Refuser l'accès à cet ordinateur depuis le réseau" ne comporte pas la mention "Invité" puis fermez la fenêtre. Maintenant, vos documents sont visibles des autres ordinateurs du réseau et la procédure est terminée.

Partager sa connexion internet

2013-01-31T11:49:00.002-08:00

Le partage d'une connexion internet sous Windows XP est très simple. Nous supposerons que votre réseau local est déjà créé. Si votre réseau n'est pas encore créé, vous pouvez regarder cet article : Tutorial de création d'un réseau local.
Une fois votre réseau créé, il nous reste à partager la connexion internet proprement dite. Si vous avez appliqué quelques astuces disponibles sur le site pour rendre votre ordinateur plus rapide, le partage de connexion pourra se faire avec quelques difficultés supplémentaires. Nous irons donc voir que tout va bien au niveau des paramètres du système d'exploitation.

Vérification des paramètres du système d'exploitation :

Il s'agit surtout de vérifier que les services dont a besoin le partage de connexion peuvent être lancés à tout moment par le système d'exploitation. Pour ce faire, cliquez sur démarrer, exécuter puis tapez services.msc. Cliquez sur Ok, une fenêtre ressemblant à celle-ci devrait apparaître :

Cherchez le service nommé Client DHCP et double-cliquez dessus. Dans la zone intitulée Type de démarrage sélectionnez la valeur Automatique.

Si le service n'est pas lancé, cliquez ensuite sur le bouton Démarrer. Cliquez sur Ok puis procédez de la même façon pour le service intitulé Pare feu Windows / Partage de connexion internet.

Les services sont maintenant configurés correctement pour accepter le partage de connexion internet. Nous allons maintenant paramétrer votre connexion internet pour la partager.

Partage de la connexion proprement dit - PC hôte :

Cliquez sur le menu démarrer, puis sur Connexions réseau. Vous arrivez devant une fenêtre ressemblant à celle-ci :

Faites un clic droit sur votre connexion internet qui sera utilisée pour le partage, cliquez sur Propriétés. Dans la fenêtre qui s'ouvre, cliquez sur l'onglet Avancé. Vous arrivez devant une fenêtre ressemblant à celle-ci :

Cochez les deux cases intitulées respectivement Autoriser d'autres ordinateurs du réseau à se connecter via la connexion internet de cet ordinateur, et Etablir une connexion d'accès à distance chaque fois qu'un ordinateur de mon réseau tente de se connecter à internet.

Partage de la connexion proprement dit - PC clients :

Une fois le PC qui partagera sa connexion internet configuré, il faut maintenant paramétrer les PC clients, ceux qui bénéficieront du partage.

Pour Windows XP :

Retournez dans la fenêtre des connexions réseau puis faites un clic droit sur votre connexion au réseau local. Cliquez ensuite sur propriétés. Vous arrivez devant un écran ressemblant à celui-ci :

Sélectionnez ensuite Protocole TCP / IP puis cliquez sur Propriétés. Dans la zone intitulée Passerelle par défaut, indiquez l'adresse IP du PC hôte. Sélectionnez ensuite Utiliser l'adresse de serveur DNS suivante et indiquez les DNS de votre fournisseur d'accès (si vous ne les connaissez pas mettez l'adresse IP du PC hôte). La configuration du PC client est terminée.

Pour Windows 98 / Me :

Rendez-vous dans le panneau de configuration et double-cliquez sur l'icône Réseau. Vous arrivez devant une fenêtre ressemblant à celle-ci :

Cliquez sur l'onglet Identification et notez le nom de votre ordinateur.

Retournez ensuite sur l'onglet Configuration puis sélectionnez "TCP / IP" et cliquez sur Paramètres. Cliquez ensuite sur l'onglet passerelle. Vous arrivez devant un écran comme celui-ci :

Indiquez dans la zone intitulée nouvelle passerelle l'adresse IP du PC hôte, puis cliquez sur Ajouter. Cliquez ensuite sur l'onglet Configuration DNS. Un écran de ce style apparaît :

Sélectionnez Activer DNS. Dans la zone Hôte, indiquez le nom que vous avez noté tout à l'heure. Dans la zone Ordre de recherche DNS, indiquez un DNS de votre fournisseur d'accès puis cliquez sur Ajouter. Faites de même avec le second DNS fourni par votre fournisseur d'accès. Cliquez ensuite sur Ok, fermez tout et redémarrez votre PC.