Seo Tips|PHP|interview questions|hosting|Job|News|Top websites blogs list|Top classifieds

Convert CSV to PHP

PMA05:21

Every once in a while, I have a static list of values that I don't want to put into a database, but that I do want to use in my PHP application. That static data can come from a variety of sources, but often it's in a spreadsheet. This handy hack converts any CSV data (one of the easiest formats to pull from a spreadsheet) to PHP code that I can then copy and paste into my PHP page.

<html>
<body>
<form method="post" action="commaconv.php" />
<table>
<tr><td>CSV Data:</td>
<td><textarea name="data" cols="40" rows="10">
"Alabama",4530182
"Alaska",655435
"Arizona",5743834
"Arkansas",2752629
"California",35893799
"Colorado",4601403
"Connecticut",3503604 
"Delaware",830364 
"District of Columbia",553523 
"Florida",17397161 
"Georgia",8829383 
"Hawaii",1262840 
"Idaho",1393262 
"Illinois",12713634 
"Indiana",6237569

"Iowa",2954451
"Kansas",2735502 
"Kentucky",4145922 
"Louisiana",4515770 
"Maine",1317253 
"Maryland",5558058 
"Massachusetts",6416505 
"Michigan",10112620 
"Minnesota",5100958 
"Mississippi",2902966 
"Missouri",5754618 
"Montana",926865 
"Nebraska",1747214 
"Nevada",2334771 
"New Hampshire",1299500 
"New Jersey",8698879 
"New Mexico",1903289 
"New York",19227088 
"North Carolina",8541221 
"North Dakota",634366 
"Ohio",11459011 
"Oklahoma",3523553 
"Oregon",3594586 
"Pennsylvania",12406292 
"Rhode Island",1080632 
"South Carolina",4198068 
"South Dakota",770883 
"Tennessee",5900962 
"Texas",22490022 
"Utah",2389039 
"Vermont",621394 
"Virginia",7459827 
"Washington",6203788 
"West Virginia",1815354 
"Wisconsin",5509026 
"Wyoming",506529</textarea></td></tr>
<tr><td> Field Name 1:</td><td><input name="field0" value="state" /></td></tr>
<tr><td> Field Name 2:</td><td><input name="field1" value="population" /></td>
		  </tr>
<tr><td> Field Name 3:</td><td><input name="field2" value="" /></td></tr>
<tr><td> Field Name 4:</td><td><input name="field3" value="" /></td></tr>
<tr><td> Field Name 5:</td><td><input name="field4" value="" /></td></tr>
</table>
<input type="submit" />
</form>
</body>
</html>

ommaconv.phphandles the data conversion.

PHP that converts data from CSV just as easily as from XML or SQL

<html><body>
<div style="font-family:courier; font-size:small;">
$data = array(<br/>
<?
$fieldnames = array(
  $_POST['field0' ],
  $_POST['field1' ],
  $_POST['field2' ],
  $_POST['field3' ],
  $_POST['field4' ] );
$rows = split( "\n", $_POST['data'] );
$index = 0;
foreach( $rows as $row )
{
  if ( $index != 0 )
    print( ",<br/>" );
  $index++;
	  print( " array(" );
  $fields = split( ",", $row );
  for( $f = 0; $f < count( $fields ); $f++ )
  {
	  
    $data = $fields[ $f ];
	$data = preg_replace( "/\\\\\"/", "\"", $data );

	if ( $f > 0 )
	  print( ", " );
	print( $fieldnames[ $f ] );
	print( " => " );
	print( $data );
	}
	print( " )" );
  }
  ?><br/>
  );
  </div>
  </body></html>

Using Cookie Authentication PHP

PMA02:19

Store authentication status in a cookie or as part of a session. When a user logs in
successfully, put their username in a cookie. Also include a hash of the username and a secret
word so a user can't just make up an authentication cookie with a username in it:

$secret_word = 'if i ate spinach';
if (pc_validate($_REQUEST['username'],$_REQUEST['password'])) {
setcookie('login',
$_REQUEST['username'].','.md5($_REQUEST['username'].$secret_word));
}
Discussion
When using cookie authentication, you have to display your own login form:
<form method="post" action="login.php">
Username: <input type="text" name="username"> <br>
Password: <input type="password" name="password"> <br>
<input type="submit" value="Log In">
</form>
You can use the same pc_validate( ) function from the Recipe 8.10 to verify the username
and password. The only difference is that you pass it $_REQUEST['username'] and
$_REQUEST['password'] as the credentials instead of $_SERVER['PHP_AUTH_USER'] and
$_SERVER['PHP_AUTH_PW']. If the password checks out, send back a cookie that contains a
username and a hash of the username, and a secret word. The hash prevents a user from
faking a login just by sending a cookie with a username in it.
Once the user has logged in, a page just needs to verify that a valid login cookie was sent in
order to do special things for that logged-in user:
unset($username);
if ($_COOKIE['login']) {
list($c_username,$cookie_hash) = split(',',$_COOKIE['login']);
if (md5($c_username.$secret_word) == $cookie_hash) {
$username = $c_username;
} else {
print "You have sent a bad cookie.";
}
}
if ($username) {
print "Welcome, $username.";
} else {
print "Welcome, anonymous user.";
}
If you use the built-in session support, you can add the username and hash to the session and
avoid sending a separate cookie. When someone logs in, set an additional variable in the
session instead of sending a cookie:
if (pc_validate($_REQUEST['username'],$_REQUEST['password'])) {
$_SESSION['login'] =
$_REQUEST['username'].','.md5($_REQUEST['username'].$secret_word));
}
The verification code is almost the same; it just uses $_SESSION instead of $_COOKIE:

unset($username);
if ($_SESSION['login']) {
list($c_username,$cookie_hash) = explode(',',$_SESSION['login']);
if (md5($c_username.$secret_word) == $cookie_hash) {
$username = $c_username;
} else {
print "You have tampered with your session.";
}
}
Using cookie or session authentication instead of HTTP Basic authentication makes it much
easier for users to log out: you just delete their login cookie or remove the login variable from
their session. Another advantage of storing authentication information in a session is that you
can link users' browsing activities while logged in to their browsing activities before they log in
or after they log out. With HTTP Basic authentication, you have no way of tying the requests
with a username to the requests that the same user made before they supplied a username.
Looking for requests from the same IP address is error-prone, especially if the user is behind a
firewall or proxy server. If you are using sessions, you can modify the login procedure to log
the connection between session ID and username:
if (pc_validate($_REQUEST['username'],$_REQUEST['password'])) {
$_SESSION['login'] =
$_REQUEST['username'].','.md5($_REQUEST['username'].$secret_word));

PHP Functions

PMA05:39

A function is a named sequence of code statements that can optionally accept parameters and return a value. A function call is an expression that has a value; its value is the returned value from the function. PHP provides a large number of internal functions. The "Function Reference" section lists all of the commonly available functions. PHP also supports user-definable functions. To define a function, use the function keyword. For example:

function soundcheck($a, $b, $c) {
  return "Testing, $a, $b, $c";
}

When you define a function, be careful what name you give it. In particular, you need to make sure that the name does not conflict with any of the internal PHP functions. If you do use a function name that conflicts with an internal function, you get the following error:

Fatal error: Can't redeclare already declared function in 
filename on line N

After you define a function, you call it by passing in the appropriate arguments. For example:

echo soundcheck(4, 5, 6);

You can also create functions with optional parameters. To do so, you set a default value for each optional parameter in the definition, using C++ style. For example, here's how to make all the parameters to the soundcheck() function optional:

function soundcheck($a=1, $b=2, $c=3) {
  return "Testing, $a, $b, $c";
}

Passing Arguments to Functions

There are two ways you can pass arguments to a function: by value and by reference. To pass an argument by value, you pass in any valid expression. That expression is evaluated and the value is assigned to the corresponding parameter defined within the function. Any changes you make to the parameter within the function have no effect on the argument passed to the function. For example:

function triple($x) {
  $x=$x*3;
  return $x;
}
$var=10;
$triplevar=triple($var);

In this case, $var evaluates to 10 when triple() is called, so $x is set to 10 inside the function. When $x is tripled, that change does not affect the value of $var outside the function.

In contrast, when you pass an argument by reference, changes to the parameter within the function do affect the value of the argument outside the scope of the function. That's because when you pass an argument by reference, you must pass a variable to the function. Now the parameter in the function refers directly to the value of the variable, meaning that any changes within the function are also visible outside the function. For example:

function triple(&$x) {
  $x=$x*3;
  return $x;
}
$var=10;
triple($var);

The & that precedes $x in the triple() function definition causes the argument to be passed by reference, so the end result is that $var ends up with a value of 30.

1.10.2 Variable Scope

The scope of a variable is the context within which a variable is available. There are two scopes for variables in PHP. Global variables are available directly from the mainline PHP execution. That is, if you are not inside a function, you can access global variables directly. Unlike most other languages, functions in PHP have their own, completely separate variable scope. Take this example:

<?php
  function test( ) {
    echo $a;
  }

  $a = "Hello World";
  test( );       
?>

If you run this script you will find that there is no output. This is because the $a you are trying to access inside the test( ) function is a completely different variable from the global $a you created in the global scope just before calling the function. In order to access a globally-scoped variable from inside a function, you need to tell the function to use the global scope for that particular variable. It can be done with the global keyword like this:

<?php
  function test( ) {
    global $a;
    echo $a;
  }

  $a = "Hello World";
  test( );       
?>

Alternatively, you can use the $GLOBALS array like this:

<?php
  function test( ) {
    echo $GLOBALS['a'];
  }

  $a = "Hello World";
  test( );       
?>

In this last example, the $GLOBALS array is known as a superglobal, which is a variable that is automatically available in all scopes without needing to be declared global in order to be accessed from within a function.

Static Variables

PHP supports declaring local function variables as static. A static variable retains its value between function calls, but is still accessible only from within the function it is declared in. Static variables can be initialized; this initialization only takes place the first time the static declaration is executed. Static variables are often used as counters, as in this example:

function hitcount( )
  static $count = 0;

  if ($count == 0) {
    echo "This is the first access to this page";
  } else {
    echo "This page has been accessed $count times";
  }
  $count++;
}

PHP Web-Related Variables

PMA05:37

PHP automatically creates variables for all the data it receives in an HTTP request. This can include GET data, POST data, cookie data, and environment variables. The variables are either in PHP's global symbol table or in one of a number of superglobal arrays, depending on the value of the register_globals setting in your php.ini file.

In PHP 4.2.0 and after, the default setting for register_globals is off. With register_globals off, all the various variables that are usually available directly in the global symbol table are now available via individual superglobal arrays. There is a limited set of superglobals and they cannot be created from a user-level script. The superglobal array to use depends on the source of the variable. Here is the list:

$_GET: GET-method variables. These are the variables supplied directly in the URL. For example, with http://www.example.com/script.php?a=1&b=2, $_GET['a'] and $_GET['b'] are set to 1 and 2, respectively.
$_POST: POST-method variables. Form field data from regular POST-method forms.
$_COOKIE: Any cookies the browser sends end up in this array. The name of the cookie is the key and the cookie value becomes the array value.
$_REQUEST: This array contains all of these variables (i.e., GET, POST, and cookie). If a variable appears in multiple sources, the order in which they are imported into $_REQUEST is given by the setting of the variables_order php.ini directive. The default is 'GPC', which means GET-method variables are imported first, then POST-method variables (overriding any GET-method variables of the same name), and finally cookie variables (overriding the other two).
$_SERVER: These are variables set by your web server. Traditionally things like DOCUMENT_ROOT, REMOTE_ADDR, REMOTE_PORT, SERVER_NAME, SERVER_PORT, and many others. To get a full list, have a look at your phpinfo( ) output, or run a script like the following to have a look:

<?php
  foreach($_SERVER as $key=>$val) {
    echo '$_SERVER['.$key."] = $val<br>\n";
  }
?>

$_ENV: Any environment variables that were set when you started your web server are available in this array.
$_FILES: For RFC 1867-style file uploads the information for each uploaded file is available in this array. For example, for a file upload form containing:

<input name="userfile" type="file">

The $_FILES array will look something like this:

$_FILES['userfile']['name'] => photo.png
$_FILES['userfile']['type'] => image/png
$_FILES['userfile']['tmp_name'] => /tmp/phpo3kdGt
$_FILES['userfile']['error'] => 0
$_FILES['userfile']['size'] => 158918

Note that the 'error' field is new for PHP 4.2.0 and the values are: 0 (no error, file was uploaded); 1 (the uploaded file exceeds the upload_max_filesize directive in php.ini); 2 (the uploaded file exceeds the MAX_FILE_SIZE directive that was specified in the HTML form); 3 (the actual number of bytes uploaded was less than the specified upload file size); and 4 (no file was uploaded).

PHP Data Types

PMA05:36

PHP provides four primitive data types: integers, floating point numbers, strings, and booleans. In addition, there are two compound data types: arrays and objects.

Integers

Integers are whole numbers. The range of integers in PHP is equivalent to the range of the long data type in C. On 32-bit platforms, integer values range from -2,147,483,648 to +2,147,483,647. PHP automatically converts larger values to floating point numbers if you happen to overflow the range. An integer can be expressed in decimal (base-10), hexadecimal (base-16), or octal (base-8). For example:

$decimal=16;
$hex=0x10;
$octal=020;

Floating Point Numbers

Floating point numbers represent decimal values. The range of floating point numbers in PHP is equivalent to the range of the double type in C. On most platforms, a double can be between 1.7E-308 to 1.7E+308. A double may be expressed either as a regular number with a decimal point or in scientific notation. For example:

$var=0.017;
$var=17.0E-3

PHP also has two sets of functions that let you manipulate numbers with arbitrary precision. These two sets are known as the BC and the GMP functions. See http://www.php.net/bc and http://www.php.net/gmp for more information.

Strings

A string is a sequence of characters. A string can be delimited by single quotes or double quotes:

'PHP is cool'
"Hello, World!"

Double-quoted strings are subject to variable substitution and escape sequence handling, while single quotes are not. For example:

$a="World";
echo "Hello\t$a\n";

This displays "Hello" followed by a tab and then "World" followed by a newline. In other words, variable substitution is performed on the variable $a and the escape sequences are converted to their corresponding characters. Contrast that with:

echo 'Hello\t$a\n';

In this case, the output is exactly "Hello\t$a\n". There is no variable substitution or handling of escape sequences.

Another way to assign a string is to use what is known as the heredoc syntax. The advantage with this approach is that you do not need to escape quotes. It looks like this:

$foo = <<<EOD
  This is a "multiline" string
  assigned using the 'heredoc' syntax.
EOD;

The following table shows the escape sequences understood by PHP inside double-quoted strings.

Escape sequence	Meaning
`\n`	Linefeed (LF or 0x0A (10) in ASCII)
`\r`	Carriage return (CR or 0x0D (13) in ASCII)
`\t`	Horizontal tab (HT or 0x09 (9) in ASCII)
`\\`	Backslash
`\$`	Dollar sign
`\`"	Double quote
`\123`	Octal notation representation of a character
`\x12`	Hexadecimal notation representation of a character

Booleans

The boolean type only has two states: true and false. For example:

$flag = true;

Boolean values are most commonly used when the == or === operators perform a comparison and return the result.

Arrays

An array is a compound data type that can contain multiple data values, indexed either numerically or with strings. For example, an array of strings can be written like this:

$var[0]="Hello";
$var[1]="World";

Note that when you assign array elements like this, you do not have to use consecutive numbers to index the elements.

Showing the Browser and IP Address

PMA05:35

Here is a simple page that prints out the browser string and the IP address of the HTTP request. Create a file with the following content in your web directory, name it something like example.php3, and load it in your browser:

<html><head><title>PHP Example</title></head>
<body>
   You are using 
    <?php echo $_SERVER['HTTP_USER_AGENT'] ?>
   <br />
   and coming from 
    <?php echo $_SERVER['REMOTE_ADDR'] ?>
</body></html>

You should see something like the following in your browser window:

You are using Mozilla/5.0 (X11; U; Linux i686; en-US; 
rv:1.1b) Gecko/20020722
and coming from 127.0.0.1

1.13.2 Intelligent Form Handling

Here is a slightly more complex example. We are going to create an HTML form that asks the user to enter a name and select one or more interests from a selection box. We could do this in two files, where we separate the actual form from the data handling code, but instead, this example shows how it can be done in a single file:

<html><head><title>Form Example</title></head>
<body>
<h1>Form Example</h1>
<?
function show_form($first="", $last="", 
                   $interest="") {
 $options = array("Sports", "Business", "Travel", 
                  "Shopping", "Computers");
 if(!is_array($interest)) $interest = array( );
 ?>
 <form action="form.php" method="POST">
 First Name:
 <input type="text" name="first" 
        value="<?echo $first?>">
 <br />
 Last Name:
 <input type="text" name="last" 
        value="<?echo $last?>">
 <br />
 Interests:
 <select multiple name="interest[ ]">
 <?php
  foreach($options as $option) {
   echo "<option";
   if(in_array($option, $interest)) {
    echo " selected ";
   }
   echo "> $option</option>\n";
  }
 ?>
 </select><br />
 <input type=submit>
 </form>
<?php } // end of show_form( ) function

if($_SERVER['REQUEST_METHOD']!='POST') {
 show_form( );
} else {
 if(empty($_POST['first']) || 
    empty($_POST['last'])  ||
    empty($_POST['interest'])) {
  echo "<p>You did not fill in all the fields,";
  echo "please try again</p>\n";
  show_form($_POST['first'],$_POST['last'], 
            $_POST['interest']);
 }
 else {
  echo "<p>Thank you, $_POST[first] $_POST[last], you ";
  echo 'selected '. 
       join(' and ', $_POST['interest']);
  echo " as your interests.</p>\n";
 }
}
?>
</body></html>

There are a few things to study carefully in this example. First, we have isolated the display of the actual form to a PHP function called show_form(). This function is intelligent, in that it can take the default value for each of the form elements as an optional argument. If the user does not fill in all the form elements, we use this feature to redisplay the form with whatever values the user has already entered. This means the user only has to fill the fields he missed, which is much better than asking the user to hit the Back button or forcing him to reenter all the fields.

The Small Business Beginners Guide

PMA02:44

Promotion Methods
Search engines are not the only way to get visitors to your site and a common
sense approach will go a long way to helping you get people to your site.
Use your domain name and Web address in ALL your company’s promotional
materials. This includes business cards, brochures, newspaper ads, classified
ads, flyers, etc. If you have a real store, make sure your Web address is
printed on everything that leaves with your customers including register
receipts, shopping bags, and product packaging.
Have a placard printed with your Web address close to every register where
every customer can see it. You can even have small business cards printed
with your store name and Web address. Place these on the sales counter so
customers can take them.
Make sure your Web address appears in EVERY display ad in local
publications. Even include it in your radio commercials. Some communities
have a local cable channel that advertises local businesses. If you use this
media, get your Web address there too.
Look to the Web for more promotional ideas. Again, many sites give out free
information and guides that will give you ideas on promoting your e-business
both online and offline.
One fact is certain; promoting your Web site is going to be an ongoing
commitment. And, the more you dedicate yourself to continually promoting
your site, the more rewards you will reap.

Internet Search Engines

PMA02:43

You’ve probably used a search engine to look for information in your own
journeys into the online world. If you have, you understand how valuable they
are to users looking for sites on the Web. Without them, we’d all be forever
lost in a sea of information.
Search engines try to organize the Web into orderly subjects so us humans can
find what we’re looking for. They fall into two main categories – true search
engines and indexes.

The true search engine uses the Web page contents to categorize and index the
page. They do this by periodically releasing a software program called a
spider or bot out to the Internet to gather data about Web pages. The spider
returns this data to a computer that organizes the data and indexes the page.
True search engines are machine driven. There is little or no human
intervention involved in the whole process. And, it’s all automatic.
Indexes are another story. They are built and controlled by people. A good
example of a human-driven Web index is Yahoo!. Web sites must be
submitted to Yahoo! for review. Only after someone looks at the site and
determines what category it belongs in is the site added to the index.
Yahoo is the most used Web index, so it’s critical that you get listed – and get
listed in the right place.
Getting your site listed in an index, especially Yahoo!, can take months to
accomplish. And, the site owner has little to say about how his/her site is
listed. The person doing the reviewing and indexing has the final say.
Getting your site changed after it is included in the index is next to
impossible. So, make sure you do this right the first time. Have a list of
keywords, your site title, and other information well thought-out and saying
exactly what you want it to say.

Internet Marketing for Smart People

PMA02:41

There are some basic business rules you should follow:

• Your pages must load FAST. Most Web surfers will give you about 30
seconds before they click off. Keep your graphic files small.
• Be consistent. This means use the same colors, same backgrounds,
same typefaces, etc. throughout your entire site. If your menu is on the
left on your home page, then keep it on the left for all your pages.
• Don’t mix too many typefaces - stick to a maximum of 2 and, use
standard typefaces.
• Keep the animations to a minimum – to many can be very distracting.
• Don’t use music on a business site.
• Don’t try to be cute or kewl. This is serious business.
• Go easy on the high-tech. Just because you can do something doesn’t
mean you should.
• If you’re selling something, don’t mask it. Let your visitors know your
intentions right from the start.
• Make sure your customers can easily find your company name,
address, and telephone numbers easily. Don’t hide this information.
Begin by deciding what you want your site to accomplish and round-up all the
tools and materials you’ll need to build your site. In particular:
• Have all your content materials – stuff like images, text, and other
media you plan to use.
• Have at least the two popular Web browsers installed on your
computer - Netscape Navigator and Internet Explorer. You’ll want to
test your completed pages on both. (Your pages will appear differently
on each one.)
• Know your target audience and what you expect to offer them.
• Get an idea of the structure and scope of your site.
There are many sites on the Web that give you all the basic instruction you’ll
ever need to create Web pages. Try searching Yahoo! or your favorite search
engine for information about Web site building for beginners.

Facebook tests paid messages to strangers

PMA02:11

Most important messages go straight to your inbox on Facebook. But there's a second class of messages, including potential spam and notes from people not in your network, that the site's algorithms deem "less relevant."

These unlucky missives are dropped in the little-known "Other" folder, where they will often spend the remainder of their digital existence unseen, unread and unloved.

"Several commentators and researchers have noted that imposing a financial cost on the sender may be the most effective way to discourage unwanted messages and facilitate delivery of messages that are relevant and useful," says the post.

The "inbox delivery test" will be available only to select people using Facebook in the U.S. for now. Companies won't have access to the feature at this time, and people are limited to one paid outgoing message a week to minimize abuse.

Seo Tips|PHP|interview questions|hosting|Job|News|Top websites blogs list|Top classifieds

Convert CSV to PHP

PHP that converts data from CSV just as easily as from XML or SQL

Using Cookie Authentication PHP

PHP Functions

Passing Arguments to Functions

1.10.2 Variable Scope

Static Variables

PHP Web-Related Variables

PHP Data Types

Integers

Floating Point Numbers

Strings

Booleans

Arrays

Showing the Browser and IP Address

1.13.2 Intelligent Form Handling

The Small Business Beginners Guide

Internet Search Engines

Internet Marketing for Smart People

Facebook tests paid messages to strangers

Top Posts

Contact

Quick Links

Tech News

PHP -web Tools

PHP that converts data from CSV just as easily as from XML or SQL

Passing Arguments to Functions

1.10.2 Variable Scope

Static Variables

Integers

Floating Point Numbers

Strings

Booleans

Arrays

1.13.2 Intelligent Form Handling

Previous

Next

Home

Top Posts

Contact

Quick Links

Tech News

PHP -web Tools