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PHP Syntax
PHP code is executed on the server, and the plain HTML result is sent to the
browser.

Basic PHP Syntax
A PHP scripting block always starts with <?php and ends with ?>. A PHP scripting block can be placed
anywhere in the document.
On servers with shorthand support enabled you can start a scripting block with <? and end with ?>.
For maximum compatibility, we recommend that you use the standard form (<?php) rather than the
shorthand form.

<?php
?>
A PHP file normally contains HTML tags, just like an HTML file, and some PHP scripting code.
Below, we have an example of a simple PHP script which sends the text "Hello World" to the browser:

<html>
<body>
<?php
echo "Hello World";
?>
</body>
</html>
Each code line in PHP must end with a semicolon. The semicolon is a separator and is used to
distinguish one set of instructions from another.
There are two basic statements to output text with PHP: echo and print. In the example above we
have used the echo statement to output the text "Hello World".
Note: The file must have a .php extension. If the file has a .html extension, the PHP code will not be
executed.

Comments in PHP
In PHP, we use // to make a single-line comment or /* and */ to make a large comment block.

<html>
<body>
<?php

//This is a comment
/*
This is
a comment
block
*/
?>
</body>
</html

PHP Variables
Variables in PHP
Variables are used for storing values, like text strings, numbers or arrays.
When a variable is declared, it can be used over and over again in your script.
All variables in PHP start with a $ sign symbol.
The correct way of declaring a variable in PHP:

$var_name = value;
New PHP programmers often forget the $ sign at the beginning of the variable. In that case it will not
work.
Let's try creating a variable containing a string, and a variable containing a number:

<?php
$txt="Hello World!";
$x=16;
?>

PHP is a Loosely Typed Language
In PHP, a variable does not need to be declared before adding a value to it.
In the example above, you see that you do not have to tell PHP which data type the variable is.
PHP automatically converts the variable to the correct data type, depending on its value.
In a strongly typed programming language, you have to declare (define) the type and name of the
variable before using it.
In PHP, the variable is declared automatically when you use it.

Naming Rules for Variables
A variable name must start with a letter or an underscore "_"
A variable name can only contain alpha-numeric characters and underscores (a-z, A-Z, 0-9,
and _ )
A variable name should not contain spaces. If a variable name is more than one word, it
should be separated with an underscore ($my_string), or with capitalization ($myString)

PHP String Variables
String Variables in PHP
String variables are used for values that contains characters.
In this chapter we are going to look at the most common functions and operators used to manipulate
strings in PHP.
After we create a string we can manipulate it. A string can be used directly in a function or it can be
stored in a variable.
Below, the PHP script assigns the text "Hello World" to a string variable called $txt:

<?php
$txt="Hello World";
echo $txt;
?>
The output of the code above will be:

Hello World
Now, lets try to use some different functions and operators to manipulate the string.

The Concatenation Operator
There is only one string operator in PHP.
The concatenation operator (.) is used to put two string values together.
To concatenate two string variables together, use the concatenation operator:

<?php
$txt1="Hello World!";
$txt2="What a nice day!";
echo $txt1 . " " . $txt2;
?>

Hello World! What a nice day!
If we look at the code above you see that we used the concatenation operator two times. This is
because we had to insert a third string (a space character), to separate the two strings.

The strlen() function
The strlen() function is used to return the length of a string.
Let's find the length of a string:

<?php
echo strlen("Hello world!");
?>

12
The length of a string is often used in loops or other functions, when it is important to know when the
string ends. (i.e. in a loop, we would want to stop the loop after the last character in the string).

The strpos() function
The strpos() function is used to search for character within a string.
If a match is found, this function will return the position of the first match. If no match is found, it will
return FALSE.
Let's see if we can find the string "world" in our string:

<?php
echo strpos("Hello world!","world");
?>

6
The position of the string "world" in our string is position 6. The reason that it is 6 (and not 7), is that
the first position in the string is 0, and not 1.

PHP Operators
PHP Operators
This section lists the different operators used in PHP.
Arithmetic Operators
Operator

Description

Example

Result

+

Addition

x=2
x+2

4

-

Subtraction

x=2
5-x

3

*

Multiplication

x=4
x*5

20

/

Division

15/5
5/2

3
2.5

%

Modulus (division remainder)

5%2
10%8
10%2

1
2
0

++

Increment

x=5
x++

x=6

--

Decrement

x=5
x--

x=4

Assignment Operators
Operator

Example

Is The Same As

=

x=y

x=y

+=

x+=y

x=x+y

-=

x-=y

x=x-y

*=

x*=y

x=x*y

/=

x/=y

x=x/y

.=

x.=y

x=x.y

%=

x%=y

x=x%y

Comparison Operators
Operator

Description

Example

==

is equal to

5==8 returns false

!=

is not equal

5!=8 returns true

<>

is not equal

5<>8 returns true

>

is greater than

5>8 returns false

<

is less than

5<8 returns true

>=

is greater than or equal to

5>=8 returns false

<=

is less than or equal to

5<=8 returns true

Logical Operators
Operator

Description

Example

&&

and

x=6
y=3
(x < 10 && y > 1) returns true

||

or

x=6
y=3
(x==5 || y==5) returns false

!

not

x=6
y=3
!(x==y) returns true

PHP If...Else Statements
Conditional Statements
Very often when you write code, you want to perform different actions for different decisions.
You can use conditional statements in your code to do this.
In PHP we have the following conditional statements:
if statement - use this statement to execute some code only if a specified condition is true
if...else statement - use this statement to execute some code if a condition is true and
another code if the condition is false
if...elseif....else statement - use this statement to select one of several blocks of code to be
executed
switch statement - use this statement to select one of many blocks of code to be executed

The if Statement
Use the if statement to execute some code only if a specified condition is true.

Syntax
if (condition) code to be executed if condition is true;
The following example will output "Have a nice weekend!" if the current day is Friday:

<html>
<body>
<?php

$d=date("D");
if ($d=="Fri") echo "Have a nice weekend!";
?>
</body>
</html>
Notice that there is no ..else.. in this syntax. The code is executed only if the specified condition is
true.

The if...else Statement
Use the if....else statement to execute some code if a condition is true and another code if a condition
is false.

Syntax
if (condition)
code to be executed if condition is true;
else
code to be executed if condition is false;

Example
The following example will output "Have a nice weekend!" if the current day is Friday, otherwise it will
output "Have a nice day!":

<html>
<body>
<?php
$d=date("D");
if ($d=="Fri")
echo "Have a nice weekend!";
else
echo "Have a nice day!";
?>
</body>
</html>
If more than one line should be executed if a condition is true/false, the lines should be enclosed
within curly braces:

<html>
<body>
<?php
$d=date("D");
if ($d=="Fri")
{
echo "Hello!<br />";
echo "See you on Monday!";

}
?>
</body>
</html>

The if...elseif....else Statement
Use the if....elseif...else statement to select one of several blocks of code to be executed.

Syntax
if (condition)
elseif (condition)
else
code to be executed if condition is false;

Example
The following example will output "Have a nice weekend!" if the current day is Friday, and "Have a
nice Sunday!" if the current day is Sunday. Otherwise it will output "Have a nice day!":

<html>
<body>
<?php
$d=date("D");
if ($d=="Fri")
elseif ($d=="Sun")
echo "Have a nice Sunday!";
else
echo "Have a nice day!";
?>
</body>
</html>

PHP Switch Statement
The PHP Switch Statement
Use the switch statement to select one of many blocks of code to be executed.

Syntax
switch (n)
{
case label1:
code to be executed if n=label1;
break;
case label2:
code to be executed if n=label2;
break;
default:
code to be executed if n is different from both label1 and label2;
}
This is how it works: First we have a single expression n (most often a variable), that is evaluated
once. The value of the expression is then compared with the values for each case in the structure. If
there is a match, the block of code associated with that case is executed. Use break to prevent the
code from running into the next case automatically. The default statement is used if no match is
found.

Example
<html>
<body>
<?php
switch ($x)
{
case 1:
echo "Number 1";
break;
case 2:
echo "Number 2";
break;
case 3:
echo "Number 3";
break;
default:
echo "No number between 1 and 3";
}
?>
</body>
</html>

PHP Arrays
What is an Array?
A variable is a storage area holding a number or text. The problem is, a variable will hold only one
value.
An array is a special variable, which can store multiple values in one single variable.
If you have a list of items (a list of car names, for example), storing the cars in single variables could
look like this:

$cars1="Saab";
$cars2="Volvo";
$cars3="BMW";
However, what if you want to loop through the cars and find a specific one? And what if you had not 3
cars, but 300?
The best solution here is to use an array!
An array can hold all your variable values under a single name. And you can access the values by
referring to the array name.
Each element in the array has its own index so that it can be easily accessed.
In PHP, there are three kind of arrays:
Numeric array - An array with a numeric index
Associative array - An array where each ID key is associated with a value
Multidimensional array - An array containing one or more arrays

Numeric Arrays
A numeric array stores each array element with a numeric index.
There are two methods to create a numeric array.
1. In the following example the index are automatically assigned (the index starts at 0):

$cars=array("Saab","Volvo","BMW","Toyota");
2. In the following example we assign the index manually:

$cars[0]="Saab";
$cars[1]="Volvo";
$cars[2]="BMW";
$cars[3]="Toyota";

Example
In the following example you access the variable values by referring to the array name and index:

<?php
$cars[0]="Saab";
$cars[1]="Volvo";
$cars[2]="BMW";
$cars[3]="Toyota";
echo $cars[0] . " and " . $cars[1] . " are Swedish cars.";
?>
The code above will output:

Saab and Volvo are Swedish cars.

Associative Arrays
An associative array, each ID key is associated with a value.
When storing data about specific named values, a numerical array is not always the best way to do it.
With associative arrays we can use the values as keys and assign values to them.

Example 1
In this example we use an array to assign ages to the different persons:

$ages = array("Peter"=>32, "Quagmire"=>30, "Joe"=>34);

Example 2
This example is the same as example 1, but shows a different way of creating the array:

$ages['Peter'] = "32";
$ages['Quagmire'] = "30";
$ages['Joe'] = "34";
The ID keys can be used in a script:

<?php
$ages['Peter'] = "32";
$ages['Quagmire'] = "30";
$ages['Joe'] = "34";
echo "Peter is " . $ages['Peter'] . " years old.";
?>

Peter is 32 years old.

Multidimensional Arrays
In a multidimensional array, each element in the main array can also be an array. And each element
in the sub-array can be an array, and so on.

Example
In this example we create a multidimensional array, with automatically assigned ID keys:

$families = array
(
"Griffin"=>array
(
"Peter",
"Lois",
"Megan"
),
"Quagmire"=>array
(
"Glenn"
),
"Brown"=>array
(
"Cleveland",
"Loretta",
"Junior"
)
);
The array above would look like this if written to the output:

Array
(
[Griffin] => Array
(
[0] => Peter
[1] => Lois
[2] => Megan
)
[Quagmire] => Array
(
[0] => Glenn
)
[Brown] => Array
(
[0] =>Cleveland
[1] => Loretta
[2] => Junior
)
)

Example 2
Lets try displaying a single value from the array above:

echo "Is " . $families['Griffin'][2] .
" a part of the Griffin family?";

Is Megan a part of the Griffin family?

PHP Looping - While Loops
PHP Loops
Often when you write code, you want the same block of code to run over and over again in a row.
Instead of adding several almost equal lines in a script we can use loops to perform a task like this.
In PHP, we have the following looping statements:
while - loops through a block of code while a specified condition is true
do...while - loops through a block of code once, and then repeats the loop as long as a
specified condition is true
for - loops through a block of code a specified number of times
foreach - loops through a block of code for each element in an array

The while Loop
The while loop executes a block of code while a condition is true.

Syntax
while (condition)
{
code to be executed;
}

Example
The example below defines a loop that starts with i=1. The loop will continue to run as long as i is less
than, or equal to 5. i will increase by 1 each time the loop runs:

<html>
<body>
<?php
$i=1;
while($i<=5)
{
echo "The number is " . $i . "<br />";

$i++;
}
?>
</body>
</html>
Output:

The
The
The
The
The

number
number
number
number
number

is
is
is
is
is

1
2
3
4
5

The do...while Statement
The do...while statement will always execute the block of code once, it will then check the condition,
and repeat the loop while the condition is true.

Syntax
do
{
}
while (condition);

Example
The example below defines a loop that starts with i=1. It will then increment i with 1, and write some
output. Then the condition is checked, and the loop will continue to run as long as i is less than, or
equal to 5:

<html>
<body>
<?php
$i=1;
do
{
$i++;
}
while ($i<=5);
?>
</body>
</html>
Output:

The number is 2

The
The
The
The

number
number
number
number

is
is
is
is

3
4
5
6

PHP Looping - For Loops
The for Loop
The for loop is used when you know in advance how many times the script should run.

Syntax
for (init; condition; increment)
{
}
Parameters:
init: Mostly used to set a counter (but can be any code to be executed once at the beginning
of the loop)
condition: Evaluated for each loop iteration. If it evaluates to TRUE, the loop continues. If it
evaluates to FALSE, the loop ends.
increment: Mostly used to increment a counter (but can be any code to be executed at the
end of the loop)
Note: Each of the parameters above can be empty, or have multiple expressions (separated by
commas).

Example
The example below defines a loop that starts with i=1. The loop will continue to run as long as i is less
than, or equal to 5. i will increase by 1 each time the loop runs:

<html>
<body>
<?php
for ($i=1; $i<=5; $i++)
{
}
?>
</body>
</html>
Output:

The number is 1
The number is 2

The number is 3
The number is 4
The number is 5

The foreach Loop
The foreach loop is used to loop through arrays.

Syntax
foreach ($array as$value)
{
}
For every loop iteration, the value of the current array element is assigned to $value (and the array
pointer is moved by one) - so on the next loop iteration, you'll be looking at the next array value.

Example
The following example demonstrates a loop that will print the values of the given array:

<html>
<body>
<?php
$x=array("one","two","three");
foreach ($x as $value)
{
echo $value . "<br />";
}
?>
</body>
</html>

PHP Functions
PHP Functions
In this chapter we will show you how to create your own functions.
To keep the script from being executed when the page loads, you can put it into a function.
A function will be executed by a call to the function.
You may call a function from anywhere within a page.

Create a PHP Function
A function will be executed by a call to the function.

Syntax
function functionName()
{
}
PHP function guidelines:
Give the function a name that reflects what the function does
The function name can start with a letter or underscore (not a number)

Example
A simple function that writes my name when it is called:

<html>
<body>
<?php
function writeName()
{
echo "Kai Jim Refsnes";
}
echo "My name is ";
writeName();
?>
</body>
</html>
Output:

My name is Kai Jim Refsnes

PHP Functions - Adding parameters
To add more functionality to a function, we can add parameters. A parameter is just like a variable.
Parameters are specified after the function name, inside the parentheses.

Example 1
The following example will write different first names, but equal last name:

<html>
<body>
<?php
function writeName($fname)
{
echo $fname . " Refsnes.<br />";
}
echo "My name is ";
writeName("Kai Jim");
echo "My sister's name is ";
writeName("Hege");
echo "My brother's name is ";
writeName("Stale");
?>
</body>
</html>
Output:

My name is Kai Jim Refsnes.
My sister's name is Hege Refsnes.
My brother's name is Stale Refsnes.

Example 2
The following function has two parameters:

<html>
<body>
<?php
function writeName($fname,$punctuation)
{
echo $fname . " Refsnes" . $punctuation . "<br />";
}
echo "My name is ";
writeName("Kai Jim",".");

echo "My sister's name is ";
writeName("Hege","!");
echo "My brother's name is ";
writeName("Ståle","?");
?>
</body>
</html>
Output:

My name is Kai Jim Refsnes.
My sister's name is Hege Refsnes!
My brother's name is Ståle Refsnes?

PHP Functions - Return values
To let a function return a value, use the return statement.

Example
<html>
<body>
<?php
function add($x,$y)
{
$total=$x+$y;
return $total;
}
echo "1 + 16 = " . add(1,16);
?>
</body>
</html>
Output:

1 + 16 = 17

PHP Forms and User Input
The PHP $_GET and $_POST variables are used to retrieve information from forms,
like user input.

PHP Form Handling
The most important thing to notice when dealing with HTML forms and PHP is that any form element
in an HTML page will automatically be available to your PHP scripts.

Example
The example below contains an HTML form with two input fields and a submit button:

<html>
<body>
<form action="welcome.php" method="post">
Name: <input type="text" name="fname" />
Age: <input type="text" name="age" />
<input type="submit" />
</form>
</body>
</html>
When a user fills out the form above and click on the submit button, the form data is sent to a PHP
file, called "welcome.php":
"welcome.php" looks like this:

<html>
<body>
Welcome <?php echo $_POST["fname"]; ?>!<br />
You are <?php echo $_POST["age"]; ?> years old.
</body>
</html>
Output could be something like this:

Welcome John!
You are 28 years old.
The PHP $_GET and $_POST functions will be explained in the next chapters.

Form Validation
User input should be validated on the browser whenever possible (by client scripts). Browser
validation is faster and reduces the server load.
You should consider server validation if the user input will be inserted into a database. A good way to
validate a form on the server is to post the form to itself, instead of jumping to a different page. The
user will then get the error messages on the same page as the form. This makes it easier to discover
the error.

PHP $_GET Function
The built-in $_GET function is used to collect values in a form with method="get".

The $_GET Function
The built-in $_GET function is used to collect values from a form sent with method="get".
Information sent from a form with the GET method is visible to everyone (it will be displayed in the
browser's address bar) and has limits on the amount of information to send (max. 100 characters).

Example
<form action="welcome.php" method="get">
</form>
When the user clicks the "Submit" button, the URL sent to the server could look something like this:

http://www.w3schools.com/welcome.php?fname=Peter&age=37
The "welcome.php" file can now use the $_GET function to collect form data (the names of the form
fields will automatically be the keys in the $_GET array):

Welcome <?php echo $_GET["fname"]; ?>.<br />
You are <?php echo $_GET["age"]; ?> years old!

When to use method="get"?
When using method="get" in HTML forms, all variable names and values are displayed in the URL.
Note: This method should not be used when sending passwords or other sensitive information!
However, because the variables are displayed in the URL, it is possible to bookmark the page. This can
be useful in some cases.

Note: The get method is not suitable for large variable values; the value cannot exceed 100
characters.

PHP $_POST Function
The built-in $_POST function is used to collect values in a form with
method="post".

The $_POST Function
The built-in $_POST function is used to collect values from a form sent with method="post".
Information sent from a form with the POST method is invisible to others and has no limits on the
amount of information to send.
Note: However, there is an 8 Mb max size for the POST method, by default (can be changed by
setting the post_max_size in the php.ini file).

Example
</form>
When the user clicks the "Submit" button, the URL will look like this:

http://www.w3schools.com/welcome.php
The "welcome.php" file can now use the $_POST function to collect form data (the names of the form
fields will automatically be the keys in the $_POST array):

Welcome <?php echo $_POST["fname"]; ?>!<br />

When to use method="post"?
Information sent from a form with the POST method is invisible to others and has no limits on the
amount of information to send.
However, because the variables are not displayed in the URL, it is not possible to bookmark the page.

The PHP $_REQUEST Function

The PHP built-in $_REQUEST function contains the contents of both $_GET, $_POST, and $_COOKIE.
The $_REQUEST function can be used to collect form data sent with both the GET and POST methods.

Example
Welcome <?php echo $_REQUEST["fname"]; ?>!<br />
You are <?php echo $_REQUEST["age"]; ?> years old.

PHP Date() Function
The PHP date() function is used to format a time and/or date.

The PHP Date() Function
The PHP date() function formats a timestamp to a more readable date and time.
A timestamp is a sequence of characters, denoting the date and/or time at which a certain event
occurred.

Syntax
date(format,timestamp)
Parameter

Description

format

Required. Specifies the format of the timestamp

timestamp

Optional. Specifies a timestamp. Default is the current date and time

PHP Date() - Format the Date
The required format parameter in the date() function specifies how to format the date/time.
Here are some characters that can be used:
d - Represents the day of the month (01 to 31)
m - Represents a month (01 to 12)
Y - Represents a year (in four digits)
A list of all the characters that can be used in the format parameter, can be found in our PHP Date
reference.
Other characters, like"/", ".", or "-" can also be inserted between the letters to add additional
formatting:

<?php
echo date("Y/m/d") . "<br />";
echo date("Y.m.d") . "<br />";
echo date("Y-m-d")
?>
The output of the code above could be something like this:

2009/05/11
2009.05.11
2009-05-11

PHP Date() - Adding a Timestamp
The optional timestamp parameter in the date() function specifies a timestamp. If you do not specify a
timestamp, the current date and time will be used.
The mktime() function returns the Unix timestamp for a date.
The Unix timestamp contains the number of seconds between the Unix Epoch (January 1 1970
00:00:00 GMT) and the time specified.

Syntax for mktime()
mktime(hour,minute,second,month,day,year,is_dst)
To go one day in the future we simply add one to the day argument of mktime():

<?php
$tomorrow = mktime(0,0,0,date("m"),date("d")+1,date("Y"));
echo "Tomorrow is ".date("Y/m/d", $tomorrow);
?>
The output of the code above could be something like this:

Tomorrow is 2009/05/12

PHP Include File
Server Side Includes (SSI)
You can insert the content of one PHP file into another PHP file before the server executes it, with the
include() or require() function.
The two functions are identical in every way, except how they handle errors:
include() generates a warning, but the script will continue execution
require() generates a fatal error, and the script will stop
These two functions are used to create functions, headers, footers, or elements that will be reused on
multiple pages.
Server side includes saves a lot of work. This means that you can create a standard header, footer, or
menu file for all your web pages. When the header needs to be updated, you can only update the
include file, or when you add a new page to your site, you can simply change the menu file (instead of
updating the links on all your web pages).

PHP include() Function
The include() function takes all the content in a specified file and includes it in the current file.

If an error occurs, the include() function generates a warning, but the script will continue execution.

Example 1
Assume that you have a standard header file, called "header.php". To include the header file in a
page, use the include() function:

<html>
<body>
<?php include("header.php"); ?>
<h1>Welcome to my home page!</h1>
<p>Some text.</p>
</body>
</html>

Example 2
Assume we have a standard menu file, called "menu.php", that should be used on all pages:

<a
<a
<a
<a
<a
<a

href="/default.php">Home</a>
href="/tutorials.php">Tutorials</a>
href="/references.php">References</a>
href="/examples.php">Examples</a>
href="/about.php">About Us</a>
href="/contact.php">Contact Us</a>

All pages in the Web site should include this menu file. Here is how it can be done:

<html>
<body>
<div class="leftmenu">
<?php include("menu.php"); ?>
</div>
<h1>Welcome to my home page.</h1>
<p>Some text.</p>
</body>
</html>
If you look at the source code of the page above (in a browser), it will look like this:

<html>
<body>
<div class="leftmenu">
<a href="/default.php">Home</a>
<a href="/tutorials.php">Tutorials</a>
<a href="/references.php">References</a>
<a href="/examples.php">Examples</a>
<a href="/about.php">About Us</a>
<a href="/contact.php">Contact Us</a>

</div>
<h1>Welcome to my home page!</h1>
<p>Some text.</p>
</body>
</html>

PHP require() Function
The require() function is identical to include(), except that it handles errors differently.
If an error occurs, the include() function generates a warning, but the script will continue execution.
The require() generates a fatal error, and the script will stop.

Error Example include() Function
<html>
<body>
<?php
include("wrongFile.php");
echo "Hello World!";
?>
</body>
</html>
Error message:

Warning: include(wrongFile.php) [function.include]:
failed to open stream:
No such file or directory in C:homewebsitetest.php on line 5
Warning: include() [function.include]:
Failed opening 'wrongFile.php' for inclusion
(include_path='.;C:php5pear')
in C:homewebsitetest.php on line 5
Hello World!
Notice that the echo statement is executed! This is because a Warning does not stop the script
execution.

Error Example require() Function
Now, let's run the same example with the require() function.

<html>
<body>
<?php
require("wrongFile.php");
echo "Hello World!";

?>
</body>
</html>
Error message:

Warning: require(wrongFile.php) [function.require]:
failed to open stream:
No such file or directory in C:homewebsitetest.php on line 5
Fatal error: require() [function.require]:
Failed opening required 'wrongFile.php'
(include_path='.;C:php5pear')
in C:homewebsitetest.php on line 5
The echo statement is not executed, because the script execution stopped after the fatal error.
It is recommended to use the require() function instead of include(), because scripts should not
continue after an error.

PHP File Handling
The fopen() function is used to open files in PHP.

Opening a File
The fopen() function is used to open files in PHP.
The first parameter of this function contains the name of the file to be opened and the second
parameter specifies in which mode the file should be opened:

<html>
<body>
<?php
$file=fopen("welcome.txt","r");
?>
</body>
</html>
The file may be opened in one of the following modes:
Modes

Description

r

Read only. Starts at the beginning of the file

r+

Read/Write. Starts at the beginning of the file

w

Write only. Opens and clears the contents of file; or creates a new file if it doesn't

exist
w+

Read/Write. Opens and clears the contents of file; or creates a new file if it
doesn't exist

a

Append. Opens and writes to the end of the file or creates a new file if it doesn't
exist

a+

Read/Append. Preserves file content by writing to the end of the file

x

Write only. Creates a new file. Returns FALSE and an error if file already exists

x+

Read/Write. Creates a new file. Returns FALSE and an error if file already exists

Note: If the fopen() function is unable to open the specified file, it returns 0 (false).

Example
The following example generates a message if the fopen() function is unable to open the specified file:

<html>
<body>
<?php
$file=fopen("welcome.txt","r") or exit("Unable to open file!");
?>
</body>
</html>

Closing a File
The fclose() function is used to close an open file:

<?php
$file = fopen("test.txt","r");
//some code to be executed
fclose($file);
?>

Check End-of-file
The feof() function checks if the "end-of-file" (EOF) has been reached.
The feof() function is useful for looping through data of unknown length.
Note: You cannot read from files opened in w, a, and x mode!

if (feof($file)) echo "End of file";

Reading a File Line by Line
The fgets() function is used to read a single line from a file.
Note: After a call to this function the file pointer has moved to the next line.

Example
The example below reads a file line by line, until the end of file is reached:

<?php
$file = fopen("welcome.txt", "r") or exit("Unable to open file!");
//Output a line of the file until the end is reached
while(!feof($file))
{
echo fgets($file). "<br />";
}
fclose($file);
?>

Reading a File Character by Character
The fgetc() function is used to read a single character from a file.
Note: After a call to this function the file pointer moves to the next character.

Example
The example below reads a file character by character, until the end of file is reached:

<?php
$file=fopen("welcome.txt","r") or exit("Unable to open file!");
while (!feof($file))
{
echo fgetc($file);
}
fclose($file);
?>

PHP File Upload
With PHP, it is possible to upload files to the server.

Create an Upload-File Form
To allow users to upload files from a form can be very useful.
Look at the following HTML form for uploading files:

O9
Notice the following about the HTML form above:
The enctype attribute of the <form> tag specifies which content-type to use when submitting
the form. "multipart/form-data" is used when a form requires binary data, like the contents of
a file, to be uploaded
The type="file" attribute of the <input> tag specifies that the input should be processed as a
file. For example, when viewed in a browser, there will be a browse-button next to the input
field
Note: Allowing users to upload files is a big security risk. Only permit trusted users to perform file
uploads.

Create The Upload Script
The "upload_file.php" file contains the code for uploading a file:

<?php
if ($_FILES["file"]["error"] > 0)
{
echo "Error: " . $_FILES["file"]["error"] . "<br />";
}
else
{
echo "Upload: " . $_FILES["file"]["name"] . "<br />";
echo "Type: " . $_FILES["file"]["type"] . "<br />";
echo "Size: " . ($_FILES["file"]["size"] / 1024) . " Kb<br />";
echo "Stored in: " . $_FILES["file"]["tmp_name"];
}
?>
By using the global PHP $_FILES array you can upload files from a client computer to the remote
server.
The first parameter is the form's input name and the second index can be either "name", "type",
"size", "tmp_name" or "error". Like this:
$_FILES["file"]["name"] - the name of the uploaded file

$_FILES["file"]["type"] - the type of the uploaded file
$_FILES["file"]["size"] - the size in bytes of the uploaded file
$_FILES["file"]["tmp_name"] - the name of the temporary copy of the file stored on the server
$_FILES["file"]["error"] - the error code resulting from the file upload
This is a very simple way of uploading files. For security reasons, you should add restrictions on what
the user is allowed to upload.

Restrictions on Upload
In this script we add some restrictions to the file upload. The user may only upload .gif or .jpeg files
and the file size must be under 20 kb:

<?php
if ((($_FILES["file"]["type"] == "image/gif")
|| ($_FILES["file"]["type"] == "image/jpeg")
|| ($_FILES["file"]["type"] == "image/pjpeg"))
&& ($_FILES["file"]["size"] < 20000))
{
{
echo "Error: " . $_FILES["file"]["error"] . "<br />";
}
else
{
echo "Stored in: " . $_FILES["file"]["tmp_name"];
}
}
else
{
echo "Invalid file";
}
?>
Note: For IE to recognize jpg files the type must be pjpeg, for FireFox it must be jpeg.

Saving the Uploaded File
The examples above create a temporary copy of the uploaded files in the PHP temp folder on the
server.
The temporary copied files disappears when the script ends. To store the uploaded file we need to
copy it to a different location:

<?php
if ((($_FILES["file"]["type"] == "image/gif")
|| ($_FILES["file"]["type"] == "image/jpeg")
|| ($_FILES["file"]["type"] == "image/pjpeg"))
&& ($_FILES["file"]["size"] < 20000))

{
{
echo "Return Code: " . $_FILES["file"]["error"] . "<br />";
}
else
{
echo "Temp file: " . $_FILES["file"]["tmp_name"] . "<br />";
if (file_exists("upload/" . $_FILES["file"]["name"]))
{
echo $_FILES["file"]["name"] . " already exists. ";
}
else
{
move_uploaded_file($_FILES["file"]["tmp_name"],
"upload/" . $_FILES["file"]["name"]);
echo "Stored in: " . "upload/" . $_FILES["file"]["name"];
}
}
}
else
{
echo "Invalid file";
}
?>
The script above checks if the file already exists, if it does not, it copies the file to the specified folder.
Note: This example saves the file to a new folder called "upload"

PHP Cookies
A cookie is often used to identify a user.

What is a Cookie?

A cookie is often used to identify a user. A cookie is a small file that the server embeds on the user's
computer. Each time the same computer requests a page with a browser, it will send the cookie too.
With PHP, you can both create and retrieve cookie values.

How to Create a Cookie?
The setcookie() function is used to set a cookie.
Note: The setcookie() function must appear BEFORE the <html> tag.

Syntax
setcookie(name, value, expire, path, domain);

Example 1
In the example below, we will create a cookie named "user" and assign the value "Alex Porter" to it.
We also specify that the cookie should expire after one hour:

<?php
setcookie("user", "Alex Porter", time()+3600);
?>
<html>
.....
Note: The value of the cookie is automatically URLencoded when sending the cookie, and
automatically decoded when received (to prevent URLencoding, use setrawcookie() instead).

Example 2
You can also set the expiration time of the cookie in another way. It may be easier than using
seconds.

<?php
$expire=time()+60*60*24*30;
setcookie("user", "Alex Porter", $expire);
?>
<html>
.....
In the example above the expiration time is set to a month (60 sec * 60 min * 24 hours * 30 days).

How to Retrieve a Cookie Value?
The PHP $_COOKIE variable is used to retrieve a cookie value.
In the example below, we retrieve the value of the cookie named "user" and display it on a page:

<?php
// Print a cookie
echo $_COOKIE["user"];
// A way to view all cookies
print_r($_COOKIE);
?>
In the following example we use the isset() function to find out if a cookie has been set:

<html>
<body>
<?php
if (isset($_COOKIE["user"]))
echo "Welcome " . $_COOKIE["user"] . "!<br />";
else
echo "Welcome guest!<br />";
?>
</body>
</html>

How to Delete a Cookie?
When deleting a cookie you should assure that the expiration date is in the past.
Delete example:

<?php
// set the expiration date to one hour ago
setcookie("user", "", time()-3600);
?>

What if a Browser Does NOT Support Cookies?
If your application deals with browsers that do not support cookies, you will have to use other
methods to pass information from one page to another in your application. One method is to pass the
data through forms (forms and user input are described earlier in this tutorial).
The form below passes the user input to "welcome.php" when the user clicks on the "Submit" button:

<html>
<body>
Name: <input type="text" name="name" />
</form>

</body>
</html>
Retrieve the values in the "welcome.php" file like this:

<html>
<body>
Welcome <?php echo $_POST["name"]; ?>.<br />
</body>
</html>

PHP Sessions
A PHP session variable is used to store information about, or change settings for a
user session. Session variables hold information about one single user, and are
available to all pages in one application.

PHP Session Variables
When you are working with an application, you open it, do some changes and then you close it. This is
much like a Session. The computer knows who you are. It knows when you start the application and
when you end. But on the internet there is one problem: the web server does not know who you are
and what you do because the HTTP address doesn't maintain state.
A PHP session solves this problem by allowing you to store user information on the server for later use
(i.e. username, shopping items, etc). However, session information is temporary and will be deleted
after the user has left the website. If you need a permanent storage you may want to store the data
in a database.
Sessions work by creating a unique id (UID) for each visitor and store variables based on this UID.
The UID is either stored in a cookie or is propagated in the URL.

Starting a PHP Session
Before you can store user information in your PHP session, you must first start up the session.
Note: The session_start() function must appear BEFORE the <html> tag:

<?php session_start(); ?>
<html>
<body>
</body>

</html>
The code above will register the user's session with the server, allow you to start saving user
information, and assign a UID for that user's session.

Storing a Session Variable
The correct way to store and retrieve session variables is to use the PHP $_SESSION variable:

<?php
session_start();
// store session data
$_SESSION['views']=1;
?>
<html>
<body>
<?php
//retrieve session data
echo "Pageviews=". $_SESSION['views'];
?>
</body>
</html>
Output:

Pageviews=1
In the example below, we create a simple page-views counter. The isset() function checks if the
"views" variable has already been set. If "views" has been set, we can increment our counter. If
"views" doesn't exist, we create a "views" variable, and set it to 1:

<?php
session_start();
if(isset($_SESSION['views']))
$_SESSION['views']=$_SESSION['views']+1;
else
$_SESSION['views']=1;
echo "Views=". $_SESSION['views'];
?>

Destroying a Session
If you wish to delete some session data, you can use the unset() or the session_destroy() function.
The unset() function is used to free the specified session variable:

<?php
unset($_SESSION['views']);
?>
You can also completely destroy the session by calling the session_destroy() function:

<?php
session_destroy();
?>
Note: session_destroy() will reset your session and you will lose all your stored session data.

PHP Sending E-mails
PHP allows you to send e-mails directly from a script.

The PHP mail() Function
The PHP mail() function is used to send emails from inside a script.
Syntax

mail(to,subject,message,headers,parameters)
Parameter

Description

to

Required. Specifies the receiver / receivers of the email

subject

Required. Specifies the subject of the email. Note: This parameter cannot contain
any newline characters

message

Required. Defines the message to be sent. Each line should be separated with a
LF (n). Lines should not exceed 70 characters

headers

Optional. Specifies additional headers, like From, Cc, and Bcc. The additional
headers should be separated with a CRLF (rn)

parameters

Optional. Specifies an additional parameter to the sendmail program

Note: For the mail functions to be available, PHP requires an installed and working email system. The
program to be used is defined by the configuration settings in the php.ini file. Read more in our PHP
Mail reference.

PHP Simple E-Mail
The simplest way to send an email with PHP is to send a text email.
In the example below we first declare the variables ($to, $subject, $message, $from, $headers), then
we use the variables in the mail() function to send an e-mail:

<?php
$to = "someone@example.com";
$subject = "Test mail";
$message = "Hello! This is a simple email message.";
$from = "someonelse@example.com";
$headers = "From: $from";
mail($to,$subject,$message,$headers);
echo "Mail Sent.";
?>

PHP Mail Form
With PHP, you can create a feedback-form on your website. The example below sends a text message
to a specified e-mail address:

<html>
<body>
<?php
if (isset($_REQUEST['email']))
//if "email" is filled out, send email
{
//send email
$email = $_REQUEST['email'] ;
$subject = $_REQUEST['subject'] ;
$message = $_REQUEST['message'] ;
mail( "someone@example.com", "Subject: $subject",
$message, "From: $email" );
echo "Thank you for using our mail form";
}
else
//if "email" is not filled out, display the form
{
echo "<form method='post' action='mailform.php'>
Email: <input name='email' type='text' /><br />
Subject: <input name='subject' type='text' /><br />
Message:<br />
<textarea name='message' rows='15' cols='40'>
</textarea><br />
<input type='submit' />
</form>";
}
?>
</body>
</html>
This is how the example above works:
First, check if the email input field is filled out
If it is not set (like when the page is first visited); output the HTML form
If it is set (after the form is filled out); send the email from the form
When submit is pressed after the form is filled out, the page reloads, sees that the email input
is set, and sends the email

Note: This is the simplest way to send e-mail, but it is not secure. In the next chapter of this tutorial
you can read more about vulnerabilities in e-mail scripts, and how to validate user input to make it
more secure.

PHP Secure E-mails
There is a weakness in the PHP e-mail script in the previous chapter.

PHP E-mail Injections
First, look at the PHP code from the previous chapter:

<html>
<body>
<?php
//if "email" is filled out, send email
{
//send email
mail("someone@example.com", "Subject: $subject",
}
else
//if "email" is not filled out, display the form
{
Message:<br />
</textarea><br />
</form>";
}
?>
</body>
</html>
The problem with the code above is that unauthorized users can insert data into the mail headers via
the input form.
What happens if the user adds the following text to the email input field in the form?

someone@example.com%0ACc:person2@example.com

%0ABcc:person3@example.com,person3@example.com,
anotherperson4@example.com,person5@example.com
%0ABTo:person6@example.com
The mail() function puts the text above into the mail headers as usual, and now the header has an
extra Cc:, Bcc:, and To: field. When the user clicks the submit button, the e-mail will be sent to all of
the addresses above!

PHP Stopping E-mail Injections
The best way to stop e-mail injections is to validate the input.
The code below is the same as in the previous chapter, but now we have added an input validator that
checks the email field in the form:

<html>
<body>
<?php
function spamcheck($field)
{
//filter_var() sanitizes the e-mail
//address using FILTER_SANITIZE_EMAIL
$field=filter_var($field, FILTER_SANITIZE_EMAIL);
//filter_var() validates the e-mail
//address using FILTER_VALIDATE_EMAIL
if(filter_var($field, FILTER_VALIDATE_EMAIL))
{
return TRUE;
}
else
{
return FALSE;
}
}
{//if "email" is filled out, proceed
//check if the email address is invalid
$mailcheck = spamcheck($_REQUEST['email']);
if ($mailcheck==FALSE)
{
echo "Invalid input";
}
else
{//send email
mail("someone@example.com", "Subject: $subject",
}
}

else
{//if "email" is not filled out, display the form
Message:<br />
</textarea><br />
</form>";
}
?>
</body>
</html>
In the code above we use PHP filters to validate input:
The FILTER_SANITIZE_EMAIL filter removes all illegal e-mail characters from a string
The FILTER_VALIDATE_EMAIL filter validates value as an e-mail address

PHP Error Handling
The default error handling in PHP is very simple. An error message with filename,
line number and a message describing the error is sent to the browser.

PHP Error Handling
When creating scripts and web applications, error handling is an important part. If your code lacks
error checking code, your program may look very unprofessional and you may be open to security
risks.
This tutorial contains some of the most common error checking methods in PHP.
We will show different error handling methods:
Simple "die()" statements
Custom errors and error triggers
Error reporting

Basic Error Handling: Using the die() function
The first example shows a simple script that opens a text file:

<?php
?>

If the file does not exist you might get an error like this:

Warning: fopen(welcome.txt) [function.fopen]: failed to open stream:
No such file or directory in C:webfoldertest.php on line 2
To avoid that the user gets an error message like the one above, we test if the file exist before we try
to access it:

<?php
if(!file_exists("welcome.txt"))
{
die("File not found");
}
else
{
}
?>
Now if the file does not exist you get an error like this:

File not found
The code above is more efficient than the earlier code, because it uses a simple error handling
mechanism to stop the script after the error.
However, simply stopping the script is not always the right way to go. Let's take a look at alternative
PHP functions for handling errors.

Creating a Custom Error Handler
Creating a custom error handler is quite simple. We simply create a special function that can be called
when an error occurs in PHP.
This function must be able to handle a minimum of two parameters (error level and error message)
but can accept up to five parameters (optionally: file, line-number, and the error context):

Syntax
error_function(error_level,error_message,
error_file,error_line,error_context)
Parameter

Description

error_level

Required. Specifies the error report level for the user-defined error. Must be a
value number. See table below for possible error report levels

error_message

Required. Specifies the error message for the user-defined error

error_file

Optional. Specifies the filename in which the error occurred

error_line

Optional. Specifies the line number in which the error occurred

error_context

Optional. Specifies an array containing every variable, and their values, in use
when the error occurred

Error Report levels
These error report levels are the different types of error the user-defined error handler can be used
for:
Value Constant

Description

2

E_WARNING

Non-fatal run-time errors. Execution of the script is not halted

8

E_NOTICE

Run-time notices. The script found something that might be an
error, but could also happen when running a script normally

256

E_USER_ERROR

Fatal user-generated error. This is like an E_ERROR set by the
programmer using the PHP function trigger_error()

512

E_USER_WARNING

Non-fatal user-generated warning. This is like an E_WARNING
set by the programmer using the PHP function trigger_error()

1024

E_USER_NOTICE

User-generated notice. This is like an E_NOTICE set by the
programmer using the PHP function trigger_error()

4096

E_RECOVERABLE_ERROR

Catchable fatal error. This is like an E_ERROR but can be caught
by a user defined handle (see also set_error_handler())

8191

E_ALL

All errors and warnings, except level E_STRICT (E_STRICT will be
part of E_ALL as of PHP 6.0)

Now lets create a function to handle errors:

function customError($errno, $errstr)
{
echo "<b>Error:</b> [$errno] $errstr<br />";
echo "Ending Script";
die();
}
The code above is a simple error handling function. When it is triggered, it gets the error level and an
error message. It then outputs the error level and message and terminates the script.
Now that we have created an error handling function we need to decide when it should be triggered.

Set Error Handler
The default error handler for PHP is the built in error handler. We are going to make the function
above the default error handler for the duration of the script.
It is possible to change the error handler to apply for only some errors, that way the script can handle
different errors in different ways. However, in this example we are going to use our custom error
handler for all errors:

set_error_handler("customError");
Since we want our custom function to handle all errors, the set_error_handler() only needed one
parameter, a second parameter could be added to specify an error level.

Example

Testing the error handler by trying to output variable that does not exist:

<?php
//error handler function
{
echo "<b>Error:</b> [$errno] $errstr";
}
//set error handler
set_error_handler("customError");
//trigger error
echo($test);
?>
The output of the code above should be something like this:

Error: [8] Undefined variable: test

Trigger an Error
In a script where users can input data it is useful to trigger errors when an illegal input occurs. In PHP,
this is done by the trigger_error() function.

Example
In this example an error occurs if the "test" variable is bigger than "1":

<?php
$test=2;
if ($test>1)
{
trigger_error("Value must be 1 or below");
}
?>

Notice: Value must be 1 or below
in C:webfoldertest.php on line 6
An error can be triggered anywhere you wish in a script, and by adding a second parameter, you can
specify what error level is triggered.
Possible error types:
E_USER_ERROR - Fatal user-generated run-time error. Errors that can not be recovered from.
Execution of the script is halted
E_USER_WARNING - Non-fatal user-generated run-time warning. Execution of the script is not
halted

E_USER_NOTICE - Default. User-generated run-time notice. The script found something that
might be an error, but could also happen when running a script normally

Example
In this example an E_USER_WARNING occurs if the "test" variable is bigger than "1". If an
E_USER_WARNING occurs we will use our custom error handler and end the script:

<?php
{
echo "Ending Script";
die();
}
//set error handler
set_error_handler("customError",E_USER_WARNING);
//trigger error
$test=2;
if ($test>1)
{
trigger_error("Value must be 1 or below",E_USER_WARNING);
}
?>

Error: [512] Value must be 1 or below
Ending Script
Now that we have learned to create our own errors and how to trigger them, lets take a look at error
logging.

Error Logging
By default, PHP sends an error log to the servers logging system or a file, depending on how the
error_log configuration is set in the php.ini file. By using the error_log() function you can send error
logs to a specified file or a remote destination.
Sending errors messages to yourself by e-mail can be a good way of getting notified of specific errors.

Send an Error Message by E-Mail
In the example below we will send an e-mail with an error message and end the script, if a specific
error occurs:

<?php

{
echo "Webmaster has been notified";
error_log("Error: [$errno] $errstr",1,
"someone@example.com","From: webmaster@example.com");
}
//set error handler
set_error_handler("customError",E_USER_WARNING);
//trigger error
$test=2;
if ($test>1)
{
trigger_error("Value must be 1 or below",E_USER_WARNING);
}
?>

Webmaster has been notified
And the mail received from the code above looks like this:

This should not be used with all errors. Regular errors should be logged on the server using the
default PHP logging system.

PHP Exception Handling

Exceptions are used to change the normal flow of a script if a specified error occurs

What is an Exception
With PHP 5 came a new object oriented way of dealing with errors.
Exception handling is used to change the normal flow of the code execution if a specified error
(exceptional) condition occurs. This condition is called an exception.
This is what normally happens when an exception is triggered:
The current code state is saved
The code execution will switch to a predefined (custom) exception handler function
Depending on the situation, the handler may then resume the execution from the saved code
state, terminate the script execution or continue the script from a different location in the code
We will show different error handling methods:
Basic use of Exceptions
Creating a custom exception handler
Multiple exceptions
Re-throwing an exception
Setting a top level exception handler
Note: Exceptions should only be used with error conditions, and should not be used to jump to
another place in the code at a specified point.

Basic Use of Exceptions
When an exception is thrown, the code following it will not be executed, and PHP will try to find the
matching "catch" block.
If an exception is not caught, a fatal error will be issued with an "Uncaught Exception" message.
Lets try to throw an exception without catching it:

<?php
//create function with an exception
function checkNum($number)
{
if($number>1)
{
throw new Exception("Value must be 1 or below");
}
return true;
}
//trigger exception
checkNum(2);
?>
The code above will get an error like this:

Fatal error:
with message
Stack trace:
checkNum(28)

Uncaught exception 'Exception'
'Value must be 1 or below' in C:webfoldertest.php:6
#0 C:webfoldertest.php(12):
#1 {main} thrown in C:webfoldertest.php on line 6

Try, throw and catch
To avoid the error from the example above, we need to create the proper code to handle an
exception.
Proper exception code should include:
1. Try - A function using an exception should be in a "try" block. If the exception does not
trigger, the code will continue as normal. However if the exception triggers, an exception is
"thrown"
2. Throw - This is how you trigger an exception. Each "throw" must have at least one "catch"
3. Catch - A "catch" block retrieves an exception and creates an object containing the exception
information
Lets try to trigger an exception with valid code:

<?php
//create function with an exception
function checkNum($number)
{
if($number>1)
{
throw new Exception("Value must be 1 or below");
}
return true;
}
//trigger exception in a "try" block
try
{
checkNum(2);
//If the exception is thrown, this text will not be shown
echo 'If you see this, the number is 1 or below';
}
//catch exception
catch(Exception $e)
{
echo 'Message: ' .$e->getMessage();
}
?>
The code above will get an error like this:

Message: Value must be 1 or below

Example explained:
The code above throws an exception and catches it:

1. The checkNum() function is created. It checks if a number is greater than 1. If it is, an
exception is thrown
2. The checkNum() function is called in a "try" block
3. The exception within the checkNum() function is thrown
4. The "catch" block retrives the exception and creates an object ($e) containing the exception
information
5. The error message from the exception is echoed by calling $e->getMessage() from the
exception object
However, one way to get around the "every throw must have a catch" rule is to set a top level
exception handler to handle errors that slip through.

Creating a Custom Exception Class
Creating a custom exception handler is quite simple. We simply create a special class with functions
that can be called when an exception occurs in PHP. The class must be an extension of the exception
class.
The custom exception class inherits the properties from PHP's exception class and you can add custom
functions to it.
Lets create an exception class:

<?php
class customException extends Exception
{
public function errorMessage()
{
//error message
$errorMsg = 'Error on line '.$this->getLine().' in '.$this->getFile()
.': <b>'.$this->getMessage().'</b> is not a valid E-Mail address';
return $errorMsg;
}
}
$email = "someone@example...com";
try
{
//check if
if(filter_var($email, FILTER_VALIDATE_EMAIL) === FALSE)
{
//throw exception if email is not valid
throw new customException($email);
}
}
catch (customException $e)
{
//display custom message
echo $e->errorMessage();
}
?>

The new class is a copy of the old exception class with an addition of the errorMessage() function.
Since it is a copy of the old class, and it inherits the properties and methods from the old class, we
can use the exception class methods like getLine() and getFile() and getMessage().

Example explained:
The code above throws an exception and catches it with a custom exception class:
1. The customException() class is created as an extension of the old exception class. This way it
inherits all methods and properties from the old exception class
2. The errorMessage() function is created. This function returns an error message if an e-mail
address is invalid
3. The $email variable is set to a string that is not a valid e-mail address
4. The "try" block is executed and an exception is thrown since the e-mail address is invalid
5. The "catch" block catches the exception and displays the error message

Multiple Exceptions
It is possible for a script to use multiple exceptions to check for multiple conditions.
It is possible to use several if..else blocks, a switch, or nest multiple exceptions. These exceptions can
use different exception classes and return different error messages:

<?php
{
{
//error message
$errorMsg = 'Error on line '.$this->getLine().' in '.$this->getFile()
.': <b>'.$this->getMessage().'</b> is not a valid E-Mail address';
return $errorMsg;
}
}
$email = "someone@example.com";
try
{
//check if
if(filter_var($email, FILTER_VALIDATE_EMAIL) === FALSE)
{
}
//check for "example" in mail address
if(strpos($email, "example") !== FALSE)
{
throw new Exception("$email is an example e-mail");
}
}
{

}
catch(Exception $e)
{
echo $e->getMessage();
}
?>

Example explained:
The code above tests two conditions and throws an exception if any of the conditions are not met:
address is invalid
3. The $email variable is set to a string that is a valid e-mail address, but contains the string
"example"
4. The "try" block is executed and an exception is not thrown on the first condition
5. The second condition triggers an exception since the e-mail contains the string "example"
6. The "catch" block catches the exception and displays the correct error message
If there was no customException catch, only the base exception catch, the exception would be handled
there

Re-throwing Exceptions
Sometimes, when an exception is thrown, you may wish to handle it differently than the standard
way. It is possible to throw an exception a second time within a "catch" block.
A script should hide system errors from users. System errors may be important for the coder, but is of
no interest to the user. To make things easier for the user you can re-throw the exception with a user
friendly message:

<?php
{
{
//error message
$errorMsg = $this->getMessage().' is not a valid E-Mail address.';
return $errorMsg;
}
}
$email = "someone@example.com";
try
{
try
{
//check for "example" in mail address
if(strpos($email, "example") !== FALSE)
{

throw new Exception($email);
}
}
catch(Exception $e)
{
//re-throw exception
}
}
{
//display custom message
}
?>

Example explained:
The code above tests if the email-address contains the string "example" in it, if it does, the exception
is re-thrown:
address is invalid
3. The $email variable is set to a string that is a valid e-mail address, but contains the string
"example"
4. The "try" block contains another "try" block to make it possible to re-throw the exception
5. The exception is triggered since the e-mail contains the string "example"
6. The "catch" block catches the exception and re-throws a "customException"
7. The "customException" is caught and displays an error message
If the exception is not caught in its current "try" block, it will search for a catch block on "higher
levels".

Set a Top Level Exception Handler
The set_exception_handler() function sets a user-defined function to handle all uncaught exceptions.

<?php
function myException($exception)
{
echo "<b>Exception:</b> " , $exception->getMessage();
}
set_exception_handler('myException');
throw new Exception('Uncaught Exception occurred');
?>

Exception: Uncaught Exception occurred

In the code above there was no "catch" block. Instead, the top level exception handler triggered. This
function should be used to catch uncaught exceptions.

Rules for exceptions
Code may be surrounded in a try block, to help catch potential exceptions
Each try block or "throw" must have at least one corresponding catch block
Multiple catch blocks can be used to catch different classes of exceptions
Exceptions can be thrown (or re-thrown) in a catch block within a try block
A simple rule: If you throw something, you have to catch it.

PHP Filter
PHP filters are used to validate and filter data coming from insecure sources, like
user input.

What is a PHP Filter?
A PHP filter is used to validate and filter data coming from insecure sources.
To test, validate and filter user input or custom data is an important part of any web application.
The PHP filter extension is designed to make data filtering easier and quicker.

Why use a Filter?
Almost all web applications depend on external input. Usually this comes from a user or another
application (like a web service). By using filters you can be sure your application gets the correct input
type.
You should always filter all external data!
Input filtering is one of the most important application security issues.
What is external data?
Input data from a form
Cookies
Web services data
Server variables
Database query results

Functions and Filters
To filter a variable, use one of the following filter functions:
filter_var() - Filters a single variable with a specified filter
filter_var_array() - Filter several variables with the same or different filters
filter_input - Get one input variable and filter it
filter_input_array - Get several input variables and filter them with the same or different filters
In the example below, we validate an integer using the filter_var() function:

<?php
$int = 123;
if(!filter_var($int, FILTER_VALIDATE_INT))
{
echo("Integer is not valid");
}
else
{
echo("Integer is valid");
}
?>
The code above uses the "FILTER_VALIDATE_INT" filter to filter the variable. Since the integer is
valid, the output of the code above will be: "Integer is valid".
If we try with a variable that is not an integer (like "123abc"), the output will be: "Integer is not
valid".
For a complete list of functions and filters, visit our PHP Filter Reference.

Validating and Sanitizing
There are two kinds of filters:
Validating filters:
Are used to validate user input
Strict format rules (like URL or E-Mail validating)
Returns the expected type on success or FALSE on failure
Sanitizing filters:
Are used to allow or disallow specified characters in a string
No data format rules
Always return the string

Options and Flags
Options and flags are used to add additional filtering options to the specified filters.

Different filters have different options and flags.
In the example below, we validate an integer using the filter_var() and the "min_range" and
"max_range" options:

<?php
$var=300;
$int_options = array(
"options"=>array
(
"min_range"=>0,
"max_range"=>256
)
);
if(!filter_var($var, FILTER_VALIDATE_INT, $int_options))
{
echo("Integer is not valid");
}
else
{
echo("Integer is valid");
}
?>
Like the code above, options must be put in an associative array with the name "options". If a flag is
used it does not need to be in an array.
Since the integer is "300" it is not in the specified range, and the output of the code above will be:
"Integer is not valid".
For a complete list of functions and filters, visit our PHP Filter Reference. Check each filter to see what
options and flags are available.

Validate Input
Let's try validating input from a form.
The first thing we need to do is to confirm that the input data we are looking for exists.
Then we filter the input data using the filter_input() function.
In the example below, the input variable "email" is sent to the PHP page:

<?php
if(!filter_has_var(INPUT_GET, "email"))
{
echo("Input type does not exist");
}
else
{
if (!filter_input(INPUT_GET, "email", FILTER_VALIDATE_EMAIL))
{

echo "E-Mail is not valid";
}
else
{
echo "E-Mail is valid";
}
}
?>

Example Explained
The example above has an input (email) sent to it using the "GET" method:
1. Check if an "email" input variable of the "GET" type exist
2. If the input variable exists, check if it is a valid e-mail address

Sanitize Input
Let's try cleaning up an URL sent from a form.
First we confirm that the input data we are looking for exists.
Then we sanitize the input data using the filter_input() function.
In the example below, the input variable "url" is sent to the PHP page:

<?php
if(!filter_has_var(INPUT_POST, "url"))
{
echo("Input type does not exist");
}
else
{
$url = filter_input(INPUT_POST,
"url", FILTER_SANITIZE_URL);
}
?>

Example Explained
The example above has an input (url) sent to it using the "POST" method:
1. Check if the "url" input of the "POST" type exists
2. If the input variable exists, sanitize (take away invalid characters) and store it in the $url
variable
If the input variable is a string like this "http://www.W3ååSchøøools.com/", the $url variable after the
sanitizing will look like this:

http://www.W3Schools.com/

Filter Multiple Inputs
A form almost always consist of more than one input field. To avoid calling the filter_var or filter_input
functions over and over, we can use the filter_var_array or the filter_input_array functions.
In this example we use the filter_input_array() function to filter three GET variables. The received GET
variables is a name, an age and an e-mail address:

<?php
$filters = array
(
"name" => array
(
"filter"=>FILTER_SANITIZE_STRING
),
"age" => array
(
"filter"=>FILTER_VALIDATE_INT,
"options"=>array
(
"min_range"=>1,
"max_range"=>120
)
),
"email"=> FILTER_VALIDATE_EMAIL,
);
$result = filter_input_array(INPUT_GET, $filters);
if (!$result["age"])
{
echo("Age must be a number between 1 and 120.<br />");
}
elseif(!$result["email"])
{
echo("E-Mail is not valid.<br />");
}
else
{
echo("User input is valid");
}
?>

Example Explained
The example above has three inputs (name, age and email) sent to it using the "GET" method:
1. Set an array containing the name of input variables and the filters used on the specified input
variables
2. Call the filter_input_array() function with the GET input variables and the array we just set
3. Check the "age" and "email" variables in the $result variable for invalid inputs. (If any of the
input variables are invalid, that input variable will be FALSE after the filter_input_array()
function)
The second parameter of the filter_input_array() function can be an array or a single filter ID.
If the parameter is a single filter ID all values in the input array are filtered by the specified filter.

If the parameter is an array it must follow these rules:
Must be an associative array containing an input variable as an array key (like the "age" input
variable)
The array value must be a filter ID or an array specifying the filter, flags and options

Using Filter Callback
It is possible to call a user defined function and use it as a filter using the FILTER_CALLBACK filter.
This way, we have full control of the data filtering.
You can create your own user defined function or use an existing PHP function
The function you wish to use to filter is specified the same way as an option is specified. In an
associative array with the name "options"
In the example below, we use a user created function to convert all "_" to whitespaces:

<?php
function convertSpace($string)
{
return str_replace("_", " ", $string);
}
$string = "Peter_is_a_great_guy!";
echo filter_var($string, FILTER_CALLBACK,
array("options"=>"convertSpace"));
?>
The result from the code above should look like this:

Peter is a great guy!

Example Explained
The example above converts all "_" to whitespaces:
1. Create a function to replace "_" to whitespaces
2. Call the filter_var() function with the FILTER_CALLBACK filter and an array containing our
function

PHP Database

PHP MySQL Introduction

MySQL is the most popular open-source database system.

What is MySQL?
MySQL is a database.
The data in MySQL is stored in database objects called tables.
A table is a collections of related data entries and it consists of columns and rows.
Databases are useful when storing information categorically. A company may have a database with
the following tables: "Employees", "Products", "Customers" and "Orders".

Database Tables
A database most often contains one or more tables. Each table is identified by a name (e.g.
"Customers" or "Orders"). Tables contain records (rows) with data.
Below is an example of a table called "Persons":
LastName

FirstName

Address

City

Hansen

Ola

Timoteivn 10

Sandnes

Svendson

Tove

Borgvn 23

Sandnes

Pettersen

Kari

Storgt 20

Stavanger

The table above contains three records (one for each person) and four columns (LastName,
FirstName, Address, and City).

Queries
A query is a question or a request.
With MySQL, we can query a database for specific information and have a recordset returned.
Look at the following query:

SELECT LastName FROM Persons
The query above selects all the data in the "LastName" column from the "Persons" table, and will
return a recordset like this:
LastName
Hansen
Svendson
Pettersen

Download MySQL Database
If you don't have a PHP server with a MySQL Database, you can download MySQL for free here:
http://www.mysql.com/downloads/index.html

Facts About MySQL Database
One great thing about MySQL is that it can be scaled down to support embedded database
applications. Perhaps it is because of this reputation that many people believe that MySQL can only
handle small to medium-sized systems.
The truth is that MySQL is the de-facto standard database for web sites that support huge volumes of
both data and end users (like Friendster, Yahoo, Google

PHP MySQL Connect to a Database
The free MySQL database is very often used with PHP.

Create a Connection to a MySQL Database
Before you can access data in a database, you must create a connection to the database.
In PHP, this is done with the mysql_connect() function.

Syntax
mysql_connect(servername,username,password);
Parameter

Description

servername

Optional. Specifies the server to connect to. Default value is "localhost:3306"

username

Optional. Specifies the username to log in with. Default value is the name of the
user that owns the server process

password

Optional. Specifies the password to log in with. Default is ""

Note: There are more available parameters, but the ones listed above are the most important. Visit
our full PHP MySQL Reference for more details.

Example
In the following example we store the connection in a variable ($con) for later use in the script. The
"die" part will be executed if the connection fails:

<?php

$con = mysql_connect("localhost","peter","abc123");
if (!$con)
{
die('Could not connect: ' . mysql_error());
}
// some code
?>

Closing a Connection
The connection will be closed automatically when the script ends. To close the connection before, use
the mysql_close() function:

<?php
if (!$con)
{
}
// some code
mysql_close($con);
?>

PHP MySQL Create Database and Tables
A database holds one or multiple tables.

Create a Database
The CREATE DATABASE statement is used to create a database in MySQL.

Syntax
CREATE DATABASE database_name
To learn more about SQL, please visit our SQL tutorial.
To get PHP to execute the statement above we must use the mysql_query() function. This function is
used to send a query or command to a MySQL connection.

Example
The following example creates a database called "my_db":

<?php
if (!$con)
{
}
if (mysql_query("CREATE DATABASE my_db",$con))
{
echo "Database created";
}
else
{
echo "Error creating database: " . mysql_error();
}
mysql_close($con);
?>

Create a Table
The CREATE TABLE statement is used to create a table in MySQL.

Syntax
CREATE TABLE
(
column_name1
column_name2
column_name3
....
)

table_name
data_type,
data_type,
data_type,

We must add the CREATE TABLE statement to the mysql_query() function to execute the command.

Example
The following example creates a table named "Persons", with three columns. The column names will
be "FirstName", "LastName" and "Age":

<?php
if (!$con)
{
}
// Create database
if (mysql_query("CREATE DATABASE my_db",$con))
{
echo "Database created";
}
else

{
echo "Error creating database: " . mysql_error();
}
// Create table
mysql_select_db("my_db", $con);
$sql = "CREATE TABLE Persons
(
FirstName varchar(15),
LastName varchar(15),
Age int
)";
// Execute query
mysql_query($sql,$con);
mysql_close($con);
?>
Important: A database must be selected before a table can be created. The database is selected with
the mysql_select_db() function.
Note: When you create a database field of type varchar, you must specify the maximum length of the
field, e.g. varchar(15).
The data type specifies what type of data the column can hold. For a complete reference of all the
data types available in MySQL, go to our complete Data Types reference.

Primary Keys and Auto Increment Fields
Each table should have a primary key field.
A primary key is used to uniquely identify the rows in a table. Each primary key value must be unique
within the table. Furthermore, the primary key field cannot be null because the database engine
requires a value to locate the record.
The following example sets the personID field as the primary key field. The primary key field is often
an ID number, and is often used with the AUTO_INCREMENT setting. AUTO_INCREMENT automatically
increases the value of the field by 1 each time a new record is added. To ensure that the primary key
field cannot be null, we must add the NOT NULL setting to the field.

Example
$sql = "CREATE TABLE Persons
(
personID int NOT NULL AUTO_INCREMENT,
PRIMARY KEY(personID),
FirstName varchar(15),
LastName varchar(15),
Age int
)";
mysql_query($sql,$con);

PHP MySQL Insert Into
The INSERT INTO statement is used to insert new records in a table.

Insert Data Into a Database Table
The INSERT INTO statement is used to add new records to a database table.

Syntax
It is possible to write the INSERT INTO statement in two forms.
The first form doesn't specify the column names where the data will be inserted, only their values:

INSERT INTO table_name
VALUES (value1, value2, value3,...)
The second form specifies both the column names and the values to be inserted:

INSERT INTO table_name (column1, column2, column3,...)
VALUES (value1, value2, value3,...)
To get PHP to execute the statements above we must use the mysql_query() function. This function is

Example
In the previous chapter we created a table named "Persons", with three columns; "Firstname",
"Lastname" and "Age". We will use the same table in this example. The following example adds two
new records to the "Persons" table:

<?php
if (!$con)
{
}
mysql_query("INSERT INTO Persons (FirstName, LastName, Age)
VALUES ('Peter', 'Griffin', '35')");
mysql_query("INSERT INTO Persons (FirstName, LastName, Age)
VALUES ('Glenn', 'Quagmire', '33')");
mysql_close($con);

?>

Insert Data From a Form Into a Database
Now we will create an HTML form that can be used to add new records to the "Persons" table.
Here is the HTML form:

<html>
<body>
<form action="insert.php" method="post">
Firstname: <input type="text" name="firstname" />
Lastname: <input type="text" name="lastname" />
</form>
</body>
</html>
When a user clicks the submit button in the HTML form in the example above, the form data is sent to
"insert.php".
The "insert.php" file connects to a database, and retrieves the values from the form with the PHP
$_POST variables.
Then, the mysql_query() function executes the INSERT INTO statement, and a new record will be
added to the "Persons" table.
Here is the "insert.php" page:

<?php
if (!$con)
{
}
$sql="INSERT INTO Persons (FirstName, LastName, Age)
VALUES
('$_POST[firstname]','$_POST[lastname]','$_POST[age]')";
if (!mysql_query($sql,$con))
{
die('Error: ' . mysql_error());
}
echo "1 record added";
mysql_close($con)
?>

PHP MySQL Select
The SELECT statement is used to select data from a database.

Select Data From a Database Table
The SELECT statement is used to select data from a database.

Syntax
SELECT column_name(s)
FROM table_name

Example
The following example selects all the data stored in the "Persons" table (The * character selects all the
data in the table):

<?php
if (!$con)
{
}
$result = mysql_query("SELECT * FROM Persons");
while($row = mysql_fetch_array($result))
{
echo $row['FirstName'] . " " . $row['LastName'];
echo "<br />";
}
mysql_close($con);
?>
The example above stores the data returned by the mysql_query() function in the $result variable.
Next, we use the mysql_fetch_array() function to return the first row from the recordset as an array.
Each call to mysql_fetch_array() returns the next row in the recordset. The while loop loops through
all the records in the recordset. To print the value of each row, we use the PHP $row variable
($row['FirstName'] and $row['LastName']).


Peter Griffin
Glenn Quagmire

Display the Result in an HTML Table
The following example selects the same data as the example above, but will display the data in an
HTML table:

<?php
if (!$con)
{
}
$result = mysql_query("SELECT * FROM Persons");
echo "<table border='1'>
<tr>
<th>Firstname</th>
<th>Lastname</th>
</tr>";
{
echo "<tr>";
echo "<td>" . $row['FirstName'] . "</td>";
echo "<td>" . $row['LastName'] . "</td>";
echo "</tr>";
}
echo "</table>";
mysql_close($con);
?>
Firstname Lastname
Glenn

Quagmire

Peter

Griffin

PHP MySQL The Where Clause
The WHERE clause is used to filter records.

The WHERE clause
The WHERE clause is used to extract only those records that fulfill a specified criterion.

Syntax
FROM table_name
WHERE column_name operator value

Example
The following example selects all rows from the "Persons" table where "FirstName='Peter':

<?php
if (!$con)
{
}
$result = mysql_query("SELECT * FROM Persons
WHERE FirstName='Peter'");
{
echo $row['FirstName'] . " " . $row['LastName'];
echo "<br />";
}
?>

Peter Griffin

PHP MySQL Order By Keyword
The ORDER BY keyword is used to sort the data in a recordset.

The ORDER BY Keyword
The ORDER BY keyword is used to sort the data in a recordset.
The ORDER BY keyword sort the records in ascending order by default.
If you want to sort the records in a descending order, you can use the DESC keyword.

Syntax
FROM table_name
ORDER BY column_name(s) ASC|DESC

Example
The following example selects all the data stored in the "Persons" table, and sorts the result by the
"Age" column:

<?php
if (!$con)
{
}
$result = mysql_query("SELECT * FROM Persons ORDER BY age");
{
echo $row['FirstName'];
echo " " . $row['LastName'];
echo " " . $row['Age'];
echo "<br />";
}
mysql_close($con);
?>

Glenn Quagmire 33
Peter Griffin 35

Order by Two Columns
It is also possible to order by more than one column. When ordering by more than one column, the
second column is only used if the values in the first column are equal:

FROM table_name
ORDER BY column1, column2

PHP MySQL Update
The UPDATE statement is used to modify data in a table.

Update Data In a Database
The UPDATE statement is used to update existing records in a table.

Syntax
UPDATE table_name
SET column1=value, column2=value2,...
WHERE some_column=some_value
Note: Notice the WHERE clause in the UPDATE syntax. The WHERE clause specifies which record or
records that should be updated. If you omit the WHERE clause, all records will be updated!

Example
Earlier in the tutorial we created a table named "Persons". Here is how it looks:
FirstName

LastName

Age

Peter

Griffin

35

Glenn

Quagmire

33

The following example updates some data in the "Persons" table:

<?php
if (!$con)
{
}
mysql_query("UPDATE Persons SET Age = '36'
WHERE FirstName = 'Peter' AND LastName = 'Griffin'");
mysql_close($con);

?>
After the update, the "Persons" table will look like this:
FirstName

LastName

Age

Peter

Griffin

36

Glenn

Quagmire

33

PHP MySQL Delete
The DELETE statement is used to delete records in a table.

Delete Data In a Database
The DELETE FROM statement is used to delete records from a database table.

Syntax
DELETE FROM table_name
WHERE some_column = some_value
Note: Notice the WHERE clause in the DELETE syntax. The WHERE clause specifies which record or
records that should be deleted. If you omit the WHERE clause, all records will be deleted!

Example
Look at the following "Persons" table:
FirstName

LastName

Age

Peter

Griffin

35

Glenn

Quagmire

33

The following example deletes all the records in the "Persons" table where LastName='Griffin':

<?php
if (!$con)
{
}

mysql_query("DELETE FROM Persons WHERE LastName='Griffin'");
mysql_close($con);
?>
After the deletion, the table will look like this:
FirstName

LastName

Age

Glenn

Quagmire

33

PHP Database ODBC
ODBC is an Application Programming Interface (API) that allows you to connect to a
data source (e.g. an MS Access database).

Create an ODBC Connection
With an ODBC connection, you can connect to any database, on any computer in your network, as
long as an ODBC connection is available.
Here is how to create an ODBC connection to a MS Access Database:
1.
2.
3.
4.
5.
6.
7.
8.

Open the Administrative Tools icon in your Control Panel.
Double-click on the Data Sources (ODBC) icon inside.
Choose the System DSN tab.
Click on Add in the System DSN tab.
Select the Microsoft Access Driver. Click Finish.
In the next screen, click Select to locate the database.
Give the database a Data Source Name (DSN).
Click OK.

Note that this configuration has to be done on the computer where your web site is located. If you are
running Internet Information Server (IIS) on your own computer, the instructions above will work, but
if your web site is located on a remote server, you have to have physical access to that server, or ask
your web host to to set up a DSN for you to use.

Connecting to an ODBC
The odbc_connect() function is used to connect to an ODBC data source. The function takes four
parameters: the data source name, username, password, and an optional cursor type.
The odbc_exec() function is used to execute an SQL statement.

Example
The following example creates a connection to a DSN called northwind, with no username and no
password. It then creates an SQL and executes it:

$conn=odbc_connect('northwind','','');
$sql="SELECT * FROM customers";
$rs=odbc_exec($conn,$sql);

Retrieving Records
The odbc_fetch_row() function is used to return records from the result-set. This function returns true
if it is able to return rows, otherwise false.
The function takes two parameters: the ODBC result identifier and an optional row number:

odbc_fetch_row($rs)

Retrieving Fields from a Record
The odbc_result() function is used to read fields from a record. This function takes two parameters:
the ODBC result identifier and a field number or name.
The code line below returns the value of the first field from the record:

$compname=odbc_result($rs,1);
The code line below returns the value of a field called "CompanyName":

$compname=odbc_result($rs,"CompanyName");

Closing an ODBC Connection
The odbc_close() function is used to close an ODBC connection.

odbc_close($conn);

An ODBC Example
The following example shows how to first create a database connection, then a result-set, and then
display the data in an HTML table.

<html>

<body>
<?php
$conn=odbc_connect('northwind','','');
if (!$conn)
{exit("Connection Failed: " . $conn);}
$sql="SELECT * FROM customers";
$rs=odbc_exec($conn,$sql);
if (!$rs)
{exit("Error in SQL");}
echo "<table><tr>";
echo "<th>Companyname</th>";
echo "<th>Contactname</th></tr>";
while (odbc_fetch_row($rs))
{
$compname=odbc_result($rs,"CompanyName");
$conname=odbc_result($rs,"ContactName");
echo "<tr><td>$compname</td>";
echo "<td>$conname</td></tr>";
}
odbc_close($conn);
echo "</table>";
?>
</body>
</html>

PHP XML
Expat Parser

PHP XML Expat Parser
The built-in Expat parser makes it possible to process XML documents in PHP.

What is XML?
XML is used to describe data and to focus on what data is. An XML file describes the structure of the
data.
In XML, no tags are predefined. You must define your own tags.
If you want to learn more about XML, please visit our XML tutorial.

What is Expat?
To read and update - create and manipulate - an XML document, you will need an XML parser.
There are two basic types of XML parsers:
Tree-based parser: This parser transforms an XML document into a tree structure. It analyzes
the whole document, and provides access to the tree elements. e.g. the Document Object
Model (DOM)
Event-based parser: Views an XML document as a series of events. When a specific event
occurs, it calls a function to handle it
The Expat parser is an event-based parser.
Event-based parsers focus on the content of the XML documents, not their structure. Because of this,
event-based parsers can access data faster than tree-based parsers.
Look at the following XML fraction:

<from>Jani</from>
An event-based parser reports the XML above as a series of three events:
Start element: from
Start CDATA section, value: Jani
Close element: from
The XML example above contains well-formed XML. However, the example is not valid XML, because
there is no Document Type Definition (DTD) associated with it.
However, this makes no difference when using the Expat parser. Expat is a non-validating parser, and
ignores any DTDs.
As an event-based, non-validating XML parser, Expat is fast and small, and a perfect match for PHP
web applications.
Note: XML documents must be well-formed or Expat will generate an error.

Installation

The XML Expat parser functions are part of the PHP core. There is no installation needed to use these
functions.

An XML File
The XML file below will be used in our example:

<?xml version="1.0" encoding="ISO-8859-1"?>
<note>
<to>Love</to>
<from>Jani</from>
<heading>Reminder</heading>
<body>Don't forget me this weekend!</body>
</note>

Initializing the XML Parser
We want to initialize the XML parser in PHP, define some handlers for different XML events, and then
parse the XML file.

Example
<?php
//Initialize the XML parser
$parser=xml_parser_create();
//Function to use at the start of an element
function start($parser,$element_name,$element_attrs)
{
switch($element_name)
{
case "NOTE":
echo "-- Note --<br />";
break;
case "TO":
echo "To: ";
break;
case "FROM":
echo "From: ";
break;
case "HEADING":
echo "Heading: ";
break;
case "BODY":
echo "Message: ";
}
}
//Function to use at the end of an element
function stop($parser,$element_name)
{
echo "<br />";

}
//Function to use when finding character data
function char($parser,$data)
{
echo $data;
}
//Specify element handler
xml_set_element_handler($parser,"start","stop");
//Specify data handler
xml_set_character_data_handler($parser,"char");
//Open XML file
$fp=fopen("test.xml","r");
//Read data
while ($data=fread($fp,4096))
{
xml_parse($parser,$data,feof($fp)) or
die (sprintf("XML Error: %s at line %d",
xml_error_string(xml_get_error_code($parser)),
xml_get_current_line_number($parser)));
}
//Free the XML parser
xml_parser_free($parser);
?>

-- Note -To: Tove
From: Jani
Heading: Reminder
Message: Don't forget me this weekend!
How it works:
1. Initialize the XML parser with the xml_parser_create() function
2. Create functions to use with the different event handlers
3. Add the xml_set_element_handler() function to specify which function will be executed when
the parser encounters the opening and closing tags
4. Add the xml_set_character_data_handler() function to specify which function will execute
when the parser encounters character data
5. Parse the file "test.xml" with the xml_parse() function
6. In case of an error, add xml_error_string() function to convert an XML error to a textual
description
7. Call the xml_parser_free() function to release the memory allocated with the
xml_parser_create() function

PHP XML DOM

The built-in DOM parser makes it possible to process XML documents in PHP.

What is DOM?
The W3C DOM provides a standard set of objects for HTML and XML documents, and a standard
interface for accessing and manipulating them.
The W3C DOM is separated into different parts (Core, XML, and HTML) and different levels (DOM Level
1/2/3):
* Core DOM - defines a standard set of objects for any structured document
* XML DOM - defines a standard set of objects for XML documents
* HTML DOM - defines a standard set of objects for HTML documents
If you want to learn more about the XML DOM, please visit our XML DOM tutorial.

XML Parsing
To read and update - create and manipulate - an XML document, you will need an XML parser.
There are two basic types of XML parsers:
Tree-based parser: This parser transforms an XML document into a tree structure. It analyzes
the whole document, and provides access to the tree elements
Event-based parser: Views an XML document as a series of events. When a specific event
occurs, it calls a function to handle it
The DOM parser is an tree-based parser.
Look at the following XML document fraction:

<from>Jani</from>
The XML DOM sees the XML above as a tree structure:
Level 1: XML Document
Level 2: Root element: <from>
Level 3: Text element: "Jani"

Installation
The DOM XML parser functions are part of the PHP core. There is no installation needed to use these
functions.

An XML File
The XML file below will be used in our example:

<note>
<to>Tove</to>
<from>Jani</from>
</note>

Load and Output XML
We want to initialize the XML parser, load the xml, and output it:

Example
<?php
$xmlDoc = new DOMDocument();
$xmlDoc->load("note.xml");
print $xmlDoc->saveXML();
?>

Tove Jani Reminder Don't forget me this weekend!
If you select "View source" in the browser window, you will see the following HTML:

<note>
<to>Tove</to>
<from>Jani</from>
</note>
The example above creates a DOMDocument-Object and loads the XML from "note.xml" into it.
Then the saveXML() function puts the internal XML document into a string, so we can output it.

Looping through XML
We want to initialize the XML parser, load the XML, and loop through all elements of the <note>
element:

Example
<?php
$xmlDoc->load("note.xml");
$x = $xmlDoc->documentElement;
foreach ($x->childNodes AS $item)
{
print $item->nodeName . " = " . $item->nodeValue . "<br />";
}
?>

#text =
to = Tove
#text =
from = Jani
#text =
heading = Reminder
#text =
body = Don't forget me this weekend!
#text =
In the example above you see that there are empty text nodes between each element.
When XML generates, it often contains white-spaces between the nodes. The XML DOM parser treats
these as ordinary elements, and if you are not aware of them, they sometimes cause problems.

PHP SimpleXML
SimpleXML handles the most common XML tasks and leaves the rest for other
extensions.

What is SimpleXML?
SimpleXML is new in PHP 5. It is an easy way of getting an element's attributes and text, if you know
the XML document's layout.
Compared to DOM or the Expat parser, SimpleXML just takes a few lines of code to read text data
from an element.
SimpleXML converts the XML document into an object, like this:
Elements - Are converted to single attributes of the SimpleXMLElement object. When there's
more than one element on one level, they're placed inside an array
Attributes - Are accessed using associative arrays, where an index corresponds to the attribute
name
Element Data - Text data from elements are converted to strings. If an element has more than
one text node, they will be arranged in the order they are found

SimpleXML is fast and easy to use when performing basic tasks like:
Reading XML files
Extracting data from XML strings
Editing text nodes or attributes
However, when dealing with advanced XML, like namespaces, you are better off using the Expat
parser or the XML DOM.

Installation
As of PHP 5.0, the SimpleXML functions are part of the PHP core. There is no installation needed to
use these functions.

Using SimpleXML
Below is an XML file:

<note>
<to>Tove</to>
<from>Jani</from>
</note>
We want to output the element names and data from the XML file above.
Here's what to do:
1.
2.
3.
4.

Load the XML file
Get the name of the first element
Create a loop that will trigger on each child node, using the children() function
Output the element name and data for each child node

Example

<?php
$xml = simplexml_load_file("test.xml");
echo $xml->getName() . "<br />";
foreach($xml->children() as $child)
{
echo $child->getName() . ": " . $child . "<br />";
}
?>

note
to: Tove
from: Jani
heading: Reminder
body: Don't forget me this weekend!

PHP &AJAX
Introduction

AJAX Introduction
AJAX is about updating parts of a web page, without reloading the whole page.

What is AJAX?

AJAX = Asynchronous JavaScript and XML.
AJAX is a technique for creating fast and dynamic web pages.
AJAX allows web pages to be updated asynchronously by exchanging small amounts of data with the
server behind the scenes. This means that it is possible to update parts of a web page, without
reloading the whole page.
Classic web pages, (which do not use AJAX) must reload the entire page if the content should change.
Examples of applications using AJAX: Google Maps, Gmail, Youtube, and Facebook tabs.

How AJAX Works

AJAX is Based on Internet Standards
AJAX is based on internet standards, and uses a combination of:
XMLHttpRequest object (to exchange data asynchronously with a server)
JavaScript/DOM (to display/interact with the information)
CSS (to style the data)
XML (often used as the format for transferring data)
AJAX applications are browser- and platform-independent!

Google Suggest
AJAX was made popular in 2005 by Google, with Google Suggest.

Google Suggest is using AJAX to create a very dynamic web interface: When you start typing in
Google's search box, a JavaScript sends the letters off to a server and the server returns a list of
suggestions.

Start Using AJAX Today
In our PHP tutorial, we will demonstrate how AJAX can update parts of a web page, without reloading
the whole page. The server script will be written in PHP.
If you want to learn more about AJAX, visit our AJAX tutorial.

PHP - AJAX and PHP
AJAX is used to create more interactive applications.

AJAX PHP Example
The following example will demonstrate how a web page can communicate with a web server while a
user type characters in an input field:

Example
Start typing a name in the input field below:

First name:
Suggestions:

Example Explained - The HTML Page
When a user types a character in the input field above, the function "showHint()" is executed. The
function is triggered by the "onkeyup" event:

<html>
<head>
<script type="text/javascript">
function showHint(str)
{
if (str.length==0)
{
document.getElementById("txtHint").innerHTML="";
return;
}
if (window.XMLHttpRequest)
{// code for IE7+, Firefox, Chrome, Opera, Safari

xmlhttp=new XMLHttpRequest();
}
else
{// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
document.getElementById("txtHint").innerHTML=xmlhttp.responseText;
}
}
xmlhttp.open("GET","gethint.php?q="+str,true);
xmlhttp.send();
}
</script>
</head
<body>
<p><b>Start typing a name in the input field below:</b></p>
<form>
First name: <input type="text" onkeyup="showHint(this.value)" size="20" />
</form>
<p>Suggestions: <span id="txtHint"></span></p>
</body>
</html>
Source code explanation:
If the input field is empty (str.length==0), the function clears the content of the txtHint placeholder
and exits the function.
If the input field is not empty, the showHint() function executes the following:
Create an XMLHttpRequest object
Create the function to be executed when the server response is ready
Send the request off to a file on the server
Notice that a parameter (q) is added to the URL (with the content of the input field)

The PHP File
The page on the server called by the JavaScript above is a PHP file called "gethint.php".
The source code in "gethint.php" checks an array of names, and returns the corresponding name(s) to
the browser:

<?php
// Fill up array with names
$a[]="Anna";

$a[]="Brittany";
$a[]="Cinderella";
$a[]="Diana";
$a[]="Eva";
$a[]="Fiona";
$a[]="Gunda";
$a[]="Hege";
$a[]="Inga";
$a[]="Johanna";
$a[]="Kitty";
$a[]="Linda";
$a[]="Nina";
$a[]="Ophelia";
$a[]="Petunia";
$a[]="Amanda";
$a[]="Raquel";
$a[]="Cindy";
$a[]="Doris";
$a[]="Eve";
$a[]="Evita";
$a[]="Sunniva";
$a[]="Tove";
$a[]="Unni";
$a[]="Violet";
$a[]="Liza";
$a[]="Elizabeth";
$a[]="Ellen";
$a[]="Wenche";
$a[]="Vicky";
//get the q parameter from URL
$q=$_GET["q"];
//lookup all hints from array if length of q>0
if (strlen($q) > 0)
{
$hint="";
for($i=0; $i<count($a); $i++)
{
if (strtolower($q)==strtolower(substr($a[$i],0,strlen($q))))
{
if ($hint=="")
{
$hint=$a[$i];
}
else
{
$hint=$hint." , ".$a[$i];
}
}
}
}
// Set output to "no suggestion" if no hint were found
// or to the correct values
if ($hint == "")
{
$response="no suggestion";

}
else
{
$response=$hint;
}
//output the response
echo $response;
?>
Explanation: If there is any text sent from the JavaScript (strlen($q) > 0), the following happens:
1.
2.
3.
4.

Find a name matching the characters sent from the JavaScript
If no match were found, set the response string to "no suggestion"
If one or more matching names were found, set the response string to all these names
The response is sent to the "txtHint" placeholder

PHP - AJAX and MySQL
AJAX can be used for interactive communication with a database.

AJAX Database Example
The following example will demonstrate how a web page can fetch information from a database with
AJAX:

Example
Selec t a pers on:

Person info will be listed here...

Example Explained - The MySQL Database
The database table we use in the example above looks like this:
id

FirstName

LastName

Age

Hometown

Job

1

Peter

Griffin

41

Quahog

Brewery

2

Lois

Griffin

40

Newport

Piano Teacher

3

Joseph

Swanson

39

Quahog

Police Officer

4

Glenn

Quagmire

41

Quahog

Pilot


When a user selects a user in the dropdown list above, a function called "showUser()" is executed. The
function is triggered by the "onchange" event:

<html>
<head>
function showUser(str)
{
if (str=="")
{
return;
}
}
else
}
{
{
}
}
xmlhttp.open("GET","getuser.php?q="+str,true);
xmlhttp.send();
}
</script>
</head>
<body>
<form>
<select name="users" onchange="showUser(this.value)">
<option value="">Select a person:</option>
<option value="1">Peter Griffin</option>
<option value="2">Lois Griffin</option>
<option value="3">Glenn Quagmire</option>
<option value="4">Joseph Swanson</option>
</select>
</form>
<br />
<div id="txtHint"><b>Person info will be listed here.</b></div>
</body>
</html>
The showUser() function does the following:
Check if a person is selected
Notice that a parameter (q) is added to the URL (with the content of the dropdown list)

The PHP File
The page on the server called by the JavaScript above is a PHP file called "getuser.php".
The source code in "getuser.php" runs a query against a MySQL database, and returns the result in an
HTML table:

<?php
$q=$_GET["q"];
$con = mysql_connect('localhost', 'peter', 'abc123');
if (!$con)
{
}
mysql_select_db("ajax_demo", $con);
$sql="SELECT * FROM user WHERE id = '".$q."'";
$result = mysql_query($sql);
echo "<table border='1'>
<tr>
<th>Firstname</th>
<th>Lastname</th>
<th>Age</th>
<th>Hometown</th>
<th>Job</th>
</tr>";
{
echo "<tr>";
echo "<td>" . $row['FirstName'] . "</td>";
echo "<td>" . $row['LastName'] . "</td>";
echo "<td>" . $row['Age'] . "</td>";
echo "<td>" . $row['Hometown'] . "</td>";
echo "<td>" . $row['Job'] . "</td>";
echo "</tr>";
}
echo "</table>";
mysql_close($con);
?>
Explanation: When the query is sent from the JavaScript to the PHP file, the following happens:
1. PHP opens a connection to a MySQL server
2. The correct person is found
3. An HTML table is created, filled with data, and sent back to the "txtHint" placeholder

PHP Example - AJAX and XML

AJAX can be used for interactive communication with an XML file.

AJAX XML Example
The following example will demonstrate how a web page can fetch information from an XML file with
AJAX:

Example
Selec t a CD:

CD info will be listed here...

When a user selects a CD in the dropdown list above, a function called "showCD()" is executed. The
function is triggered by the "onchange" event:

<html>
<head>
function showCD(str)
{
if (str=="")
{
return;
}
}
else
}
{
{
}
}
xmlhttp.open("GET","getcd.php?q="+str,true);
xmlhttp.send();
}
</script>
</head>

<body>
<form>
Select a CD:
<select name="cds" onchange="showCD(this.value)">
<option value="">Select a CD:</option>
<option value="Bob Dylan">Bob Dylan</option>
<option value="Bonnie Tyler">Bonnie Tyler</option>
<option value="Dolly Parton">Dolly Parton</option>
</select>
</form>
<div id="txtHint"><b>CD info will be listed here...</b></div>
</body>
</html>
The showCD() function does the following:
Check if a CD is selected

The PHP File
The page on the server called by the JavaScript above is a PHP file called "getcd.php".
The PHP script loads an XML document, "cd_catalog.xml", runs a query against the XML file, and
returns the result as HTML:

<?php
$q=$_GET["q"];
$xmlDoc->load("cd_catalog.xml");
$x=$xmlDoc->getElementsByTagName('ARTIST');
for ($i=0; $i<=$x->length-1; $i++)
{
//Process only element nodes
if ($x->item($i)->nodeType==1)
{
if ($x->item($i)->childNodes->item(0)->nodeValue == $q)
{
$y=($x->item($i)->parentNode);
}
}
}
$cd=($y->childNodes);

for ($i=0;$i<$cd->length;$i++)
{
//Process only element nodes
if ($cd->item($i)->nodeType==1)
{
echo("<b>" . $cd->item($i)->nodeName . ":</b> ");
echo($cd->item($i)->childNodes->item(0)->nodeValue);
echo("<br />");
}
}
?>
When the CD query is sent from the JavaScript to the PHP page, the following happens:
1. PHP creates an XML DOM object
2. Find all <artist> elements that matches the name sent from the JavaScript
3. Output the album information (send to the "txtHint" placeholder)

PHP Example - AJAX Live Search
AJAX can be used to create more user-friendly and interactive searches.

AJAX Live Search
The following example will demonstrate a live search, where you get search results while you type.
Live search has many benefits compared to traditional searching:
Results are shown as you type
Results narrow as you continue typing
If results become too narrow, remove characters to see a broader result
Search for a W3Schools page in the input field below:

The results in the example above are found in an XML file (links.xml). To make this example small and
simple, only eight results are available.

When a user types a character in the input field above, the function "showResult()" is executed. The
function is triggered by the "onkeyup" event:

<html>
<head>

The source code in "livesearch.php" searches an XML file for titles matching the search string and
returns the result:

<?php
$xmlDoc=new DOMDocument();
$xmlDoc->load("links.xml");
$x=$xmlDoc->getElementsByTagName('link');
$q=$_GET["q"];
//lookup all links from the xml file if length of q>0
if (strlen($q)>0)
{
$hint="";
for($i=0; $i<($x->length); $i++)
{
$y=$x->item($i)->getElementsByTagName('title');
$z=$x->item($i)->getElementsByTagName('url');
if ($y->item(0)->nodeType==1)
{
//find a link matching the search text
if (stristr($y->item(0)->childNodes->item(0)->nodeValue,$q))
{
if ($hint=="")
{
$hint="<a href='" .
$z->item(0)->childNodes->item(0)->nodeValue .
"' target='_blank'>" .
$y->item(0)->childNodes->item(0)->nodeValue . "</a>";
}
else
{
$hint=$hint . "<br /><a href='" .
$z->item(0)->childNodes->item(0)->nodeValue .
"' target='_blank'>" .
$y->item(0)->childNodes->item(0)->nodeValue . "</a>";
}
}
}
}
}
// Set output to "no suggestion" if no hint were found
// or to the correct values
if ($hint=="")
{
$response="no suggestion";
}
else
{
$response=$hint;
}
//output the response
echo $response;
?>

If there is any text sent from the JavaScript (strlen($q) > 0), the following happens:
Load an XML file into a new XML DOM object
Loop through all <title> elements to find matches from the text sent from the JavaScript
Sets the correct url and title in the "$response" variable. If more than one match is found, all
matches are added to the variable
If no matches are found, the $response variable is set to "no suggestion"

PHP Example - AJAX RSS Reader
An RSS Reader is used to read RSS Feeds.

AJAX RSS Reader
The following example will demonstrate an RSS reader, where the RSS-feed is loaded into a webpage
without reloading:
Selec t an RSS-f eed:

RSS-feed will be listed here...

When a user selects an RSS-feed in the dropdown list above, a function called "showResult()" is
executed. The function is triggered by the "onchange" event:

<html>
<head>
function showRSS(str)
{
if (str.length==0)
{
document.getElementById("rssOutput").innerHTML="";
return;
}
}
else
}
{
{
document.getElementById("rssOutput").innerHTML=xmlhttp.responseText;

}
}
xmlhttp.open("GET","getrss.php?q="+str,true);
xmlhttp.send();
}
</script>
</head>
<body>
<form>
<select onchange="showRSS(this.value)">
<option value="">Select an RSS-feed:</option>
<option value="Google">Google News</option>
<option value="MSNBC">MSNBC News</option>
</select>
</form>
<br />
<div id="rssOutput">RSS-feed will be listed here...</div>
</body>
</html>
The showResult() function does the following:
Check if an RSS-feed is selected

The PHP File
The page on the server called by the JavaScript above is a PHP file called "getrss.php":

<?php
$q=$_GET["q"];
//find out which feed was selected
if($q=="Google")
{
$xml=("http://news.google.com/news?ned=us&topic=h&output=rss");
}
elseif($q=="MSNBC")
{
$xml=("http://rss.msnbc.msn.com/id/3032091/device/rss/rss.xml");
}
$xmlDoc->load($xml);
//get elements from "<channel>"
$channel=$xmlDoc->getElementsByTagName('channel')->item(0);
$channel_title = $channel->getElementsByTagName('title')

->item(0)->childNodes->item(0)->nodeValue;
$channel_link = $channel->getElementsByTagName('link')
$channel_desc = $channel->getElementsByTagName('description')
//output elements from "<channel>"
echo("<p><a href='" . $channel_link
. "'>" . $channel_title . "</a>");
echo("<br />");
echo($channel_desc . "</p>");
//get and output "<item>" elements
$x=$xmlDoc->getElementsByTagName('item');
for ($i=0; $i<=2; $i++)
{
$item_title=$x->item($i)->getElementsByTagName('title')
$item_link=$x->item($i)->getElementsByTagName('link')
$item_desc=$x->item($i)->getElementsByTagName('description')
echo ("<p><a href='" . $item_link
. "'>" . $item_title . "</a>");
echo ("<br />");
echo ($item_desc . "</p>");
}
?>
When an RSS-feed is sent from the JavaScript, the following happens:
Check which feed was selected
Create a new XML DOM object
Load the RSS document in the xml variable
Extract and output elements from the channel element
Extract and output elements from the item element

PHP Example - AJAX Poll
AJAX Poll
The following example will demonstrate a poll where the result is shown without reloading.

Do you like PHP and AJAX so far?
Yes:
No:


When a user choose an option above, a function called "getVote()" is executed. The function is
triggered by the "onclick" event:

<html>
<head>
function getVote(int)
{
}
else
}
{
{
document.getElementById("poll").innerHTML=xmlhttp.responseText;
}
}
xmlhttp.open("GET","poll_vote.php?vote="+int,true);
xmlhttp.send();
}
</script>
</head>
<body>
<div id="poll">
<h3>Do you like PHP and AJAX so far?</h3>
<form>
Yes:
<input type="radio" name="vote" value="0" onclick="getVote(this.value)" />
<br />No:
<input type="radio" name="vote" value="1" onclick="getVote(this.value)" />
</form>
</div>
</body>
</html>
The getVote() function does the following:
Notice that a parameter (vote) is added to the URL (with the value of the yes or no option)

The PHP File
The page on the server called by the JavaScript above is a PHP file called "poll_vote.php":

<?php
$vote = $_REQUEST['vote'];
//get content of textfile
$filename = "poll_result.txt";
$content = file($filename);
//put content in array
$array = explode("||", $content[0]);
$yes = $array[0];
$no = $array[1];
if ($vote == 0)
{
$yes = $yes + 1;
}
if ($vote == 1)
{
$no = $no + 1;
}
//insert votes to txt file
$insertvote = $yes."||".$no;
$fp = fopen($filename,"w");
fputs($fp,$insertvote);
fclose($fp);
?>
<h2>Result:</h2>
<table>
<tr>
<td>Yes:</td>
<td>
<img src="poll.gif"
width='<?php echo(100*round($yes/($no+$yes),2)); ?>'
height='20'>
<?php echo(100*round($yes/($no+$yes),2)); ?>%
</td>
</tr>
<tr>
<td>No:</td>
<td>
<img src="poll.gif"
width='<?php echo(100*round($no/($no+$yes),2)); ?>'
height='20'>
<?php echo(100*round($no/($no+$yes),2)); ?>%
</td>
</tr>
</table>
The value is sent from the JavaScript, and the following happens:
1.
2.
3.
4.

Get the content of the "poll_result.txt" file
Put the content of the file in variables and add one to the selected variable
Write the result to the "poll_result.txt" file
Output a graphical representation of the poll result

The Text File
The text file (poll_result.txt) is where we store the data from the poll.
It is stored like this:

0||0
The first number represents the "Yes" votes, the second number represents the "No" votes.
Note: Remember to allow your web server to edit the text file. Do NOT give everyone access, just the
web server (PHP).

PHP
Reference

PHP Array Functions
The array functions allow you to manipulate arrays.
PHP supports both simple and multi-dimensional arrays. There are also specific functions for
populating arrays from database queries.

Installation
The array functions are part of the PHP core. There is no installation needed to use these functions.

PHP Array Functions
PHP: indicates the earliest version of PHP that supports the function.

Function

Description

PHP

array()

Creates an array

3

array_change_key_case()

Returns an array with all keys in lowercase or uppercase

4

array_chunk()

Splits an array into chunks of arrays

4

array_combine()

Creates an array by using one array for keys and another for 5
its values

array_count_values()

Returns an array with the number of occurrences for each
value

4

array_diff()

Compares array values, and returns the differences

4

array_diff_assoc()

Compares array keys and values, and returns the differences 4

array_diff_key()

Compares array keys, and returns the differences

5

array_diff_uassoc()

Compares array keys and values, with an additional usermade function check, and returns the differences

5

array_diff_ukey()

Compares array keys, with an additional user-made function 5
check, and returns the differences

array_fill()

Fills an array with values

4

array_filter()

Filters elements of an array using a user-made function

4

array_flip()

Exchanges all keys with their associated values in an array

4

array_intersect()

Compares array values, and returns the matches

4

array_intersect_assoc()

Compares array keys and values, and returns the matches

4

array_intersect_key()

Compares array keys, and returns the matches

5

array_intersect_uassoc()

Compares array keys and values, with an additional usermade function check, and returns the matches

5

array_intersect_ukey()

Compares array keys, with an additional user-made function 5
check, and returns the matches

array_key_exists()

Checks if the specified key exists in the array

4

array_keys()

Returns all the keys of an array

4

array_map()

Sends each value of an array to a user-made function, which 4
returns new values

array_merge()

Merges one or more arrays into one array

4

array_merge_recursive()

Merges one or more arrays into one array

4

array_multisort()

Sorts multiple or multi-dimensional arrays

4

array_pad()

Inserts a specified number of items, with a specified value,
to an array

4

array_pop()

Deletes the last element of an array

4

array_product()

Calculates the product of the values in an array

5

array_push()

Inserts one or more elements to the end of an array

4

array_rand()

Returns one or more random keys from an array

4

array_reduce()

Returns an array as a string, using a user-defined function

4

array_reverse()

Returns an array in the reverse order

4

array_search()

Searches an array for a given value and returns the key

4

array_shift()

Removes the first element from an array, and returns the
value of the removed element

4

array_slice()

Returns selected parts of an array

4

array_splice()

Removes and replaces specified elements of an array

4

array_sum()

Returns the sum of the values in an array

4

array_udiff()

Compares array values in a user-made function and returns
an array

5

array_udiff_assoc()

Compares array keys, and compares array values in a usermade function, and returns an array

5

array_udiff_uassoc()

Compares array keys and array values in user-made
functions, and returns an array

5

array_uintersect()

Compares array values in a user-made function and returns
an array

5

array_uintersect_assoc()

Compares array keys, and compares array values in a usermade function, and returns an array

5

array_uintersect_uassoc()

Compares array keys and array values in user-made
functions, and returns an array

5

array_unique()

Removes duplicate values from an array

4

array_unshift()

Adds one or more elements to the beginning of an array

4

array_values()

Returns all the values of an array

4

array_walk()

Applies a user function to every member of an array

3

array_walk_recursive()

Applies a user function recursively to every member of an
array

5

arsort()

Sorts an array in reverse order and maintain index
association

3

asort()

Sorts an array and maintain index association

3

compact()

Create array containing variables and their values

4

count()

Counts elements in an array, or properties in an object

3

current()

Returns the current element in an array

3

each()

Returns the current key and value pair from an array

3

end()

Sets the internal pointer of an array to its last element

3

extract()

Imports variables into the current symbol table from an
array

3

in_array()

Checks if a specified value exists in an array

4

key()

Fetches a key from an array

3

krsort()

Sorts an array by key in reverse order

3

ksort()

Sorts an array by key

3

list()

Assigns variables as if they were an array

3

natcasesort()

Sorts an array using a case insensitive "natural order"
algorithm

4

natsort()

Sorts an array using a "natural order" algorithm

4

next()

Advance the internal array pointer of an array

3

pos()

Alias of current()

3

prev()

Rewinds the internal array pointer

3

range()

Creates an array containing a range of elements

3

reset()

Sets the internal pointer of an array to its first element

3

rsort()

Sorts an array in reverse order

3

shuffle()

Shuffles an array

3

sizeof()

Alias of count()

3

sort()

Sorts an array

3

uasort()

Sorts an array with a user-defined function and maintain
index association

3

uksort()

Sorts an array by keys using a user-defined function

3

usort()

Sorts an array by values using a user-defined function

3

PHP Array Constants
PHP: indicates the earliest version of PHP that supports the constant.
Constant

Description

CASE_LOWER

Used with array_change_key_case() to convert array keys to
lower case

CASE_UPPER

Used with array_change_key_case() to convert array keys to
upper case

SORT_ASC

Used with array_multisort() to sort in ascending order

SORT_DESC

Used with array_multisort() to sort in descending order

SORT_REGULAR

Used to compare items normally

SORT_NUMERIC

Used to compare items numerically

SORT_STRING

Used to compare items as strings

SORT_LOCALE_STRING

Used to compare items as strings, based on the current
locale

PHP

4

COUNT_NORMAL
COUNT_RECURSIVE
EXTR_OVERWRITE
EXTR_SKIP
EXTR_PREFIX_SAME
EXTR_PREFIX_ALL
EXTR_PREFIX_INVALID
EXTR_PREFIX_IF_EXISTS
EXTR_IF_EXISTS
EXTR_REFS

PHP Calendar Functions
PHP Calendar Introduction
The calendar functions are useful when working with different calendar formats. The standard it is
based on is the Julian day count (Julian day count is a count of days starting from January 1, 4713
B.C.). Note that the Julian day count is not the same as the Julian calendar!
Note: To convert between calendar formats, you must first convert to Julian day count, then to the
calendar format.

Installation
The windows version of PHP has built-in support for the calendar extension. So, the calendar functions
will work automatically.
However, if you are running the Linux version of PHP, you will have to compile PHP with --enablecalendar to get the calendar functions to work.

PHP Calendar Functions
Function

Description

PHP

cal_days_in_month()

Returns the number of days in a month for a specified year and
calendar

4

cal_from_jd()

Converts a Julian day count into a date of a specified calendar

4

cal_info()

Returns information about a given calendar

4

cal_to_jd()

Converts a date to Julian day count

4

easter_date()

Returns the Unix timestamp for midnight on Easter of a specified
year

3

easter_days()

Returns the number of days after March 21, on which Easter falls 3
for a specified year

FrenchToJD()

Converts a French Republican date to a Julian day count

3

GregorianToJD()

Converts a Gregorian date to a Julian day count

3

JDDayOfWeek()

Returns the day of a week

3

JDMonthName()

Returns a month name

3

JDToFrench()

Converts a Julian day count to a French Republican date

3

JDToGregorian()

Converts a Julian day count to a Gregorian date

3

jdtojewish()

Converts a Julian day count to a Jewish date

3

JDToJulian()

Converts a Julian day count to a Julian date

3

jdtounix()

Converts a Julian day count to a Unix timestamp

4

JewishToJD()

Converts a Jewish date to a Julian day count

3

JulianToJD()

Converts a Julian date to a Julian day count

3

unixtojd()

Converts a Unix timestamp to a Julian day count

4

PHP Calendar Constants
Constant

Description

PHP

CAL_GREGORIAN

Gregorian calendar

3

CAL_JULIAN

Julian calendar

3

CAL_JEWISH

Jewish calendar

3

CAL_FRENCH

French Republican calendar

3

CAL_NUM_CALS

3

CAL_DOW_DAYNO

3

CAL_DOW_SHORT

3

CAL_DOW_LONG

3

CAL_MONTH_GREGORIAN_SHORT

3

CAL_MONTH_GREGORIAN_LONG

3

CAL_MONTH_JULIAN_SHORT

3

CAL_MONTH_JULIAN_LONG

3

CAL_MONTH_JEWISH

3

CAL_MONTH_FRENCH

3

CAL_EASTER_DEFAULT

4

CAL_EASTER_DEFAULT

4

CAL_EASTER_ROMAN

4

CAL_EASTER_ALWAYS_GREGORIAN

4

CAL_EASTER_ALWAYS_JULIAN

4

CAL_JEWISH_ADD_ALAFIM_GERESH

5

CAL_JEWISH_ADD_ALAFIM

5

CAL_JEWISH_ADD_GERESHAYIM

5

PHP Date / Time Functions
PHP Date / Time Introduction
The date/time functions allow you to extract and format the date and time on the server.
Note: These functions depend on the locale settings of the server!

Installation
The date/time functions are part of the PHP core. There is no installation needed to use these
functions.

Runtime Configuration

The behavior of the date/time functions is affected by settings in php.ini.
Date/Time configuration options:
Name

Description

Changeable

Specifies the default latitude (available
since PHP 5). This option is used by
date_sunrise() and date_sunset()

PHP_INI_ALL

date.default_longitude "35.2333"

Specifies the default longitude (available
since PHP 5). This option is used by
date_sunrise() and date_sunset()

PHP_INI_ALL

date.sunrise_zenith

"90.83"

Specifies the default sunrise zenith
(available since PHP 5). This option is
used by date_sunrise() and
date_sunset()

PHP_INI_ALL

date.sunset_zenith

"90.83"

Specifies the default sunset zenith
(available since PHP 5). This option is
used by date_sunrise() and
date_sunset()

PHP_INI_ALL

date.timezone

""

Specifies the default timezone (available
since PHP 5.1)

PHP_INI_ALL

date.default_latitude

Default
"31.7667"

PHP Date / Time Functions
Function

Description

PHP

checkdate()

Validates a Gregorian date

3

date_default_timezone_get()

Returns the default time zone

5

date_default_timezone_set()

Sets the default time zone

5

date_sunrise()

Returns the time of sunrise for a given day / location

5

date_sunset()

Returns the time of sunset for a given day / location

5

date()

Formats a local time/date

3

getdate()

Returns an array that contains date and time information 3
for a Unix timestamp

gettimeofday()

Returns an array that contains current time information

3

gmdate()

Formats a GMT/UTC date/time

3

gmmktime()

Returns the Unix timestamp for a GMT date

3

gmstrftime()

Formats a GMT/UTC time/date according to locale
settings

3

idate()

Formats a local time/date as integer

5

localtime()

Returns an array that contains the time components of a
Unix timestamp

4

microtime()

Returns the microseconds for the current time

3

mktime()

Returns the Unix timestamp for a date

3

strftime()

Formats a local time/date according to locale settings

3

strptime()

Parses a time/date generated with strftime()

5

strtotime()

Parses an English textual date or time into a Unix
timestamp

3

time()

Returns the current time as a Unix timestamp

3

PHP Date / Time Constants
Constant

Description

DATE_ATOM

Atom (example: 2005-08-15T16:13:03+0000)

DATE_COOKIE

HTTP Cookies (example: Sun, 14 Aug 2005 16:13:03
UTC)

DATE_ISO8601

ISO-8601 (example: 2005-08-14T16:13:03+0000)

DATE_RFC822

RFC 822 (example: Sun, 14 Aug 2005 16:13:03 UTC)

DATE_RFC850

RFC 850 (example: Sunday, 14-Aug-05 16:13:03 UTC)

DATE_RFC1036

RFC 1036 (example: Sunday, 14-Aug-05 16:13:03 UTC)

DATE_RFC1123

RFC 1123 (example: Sun, 14 Aug 2005 16:13:03 UTC)

DATE_RFC2822

RFC 2822 (Sun, 14 Aug 2005 16:13:03 +0000)

DATE_RSS

RSS (Sun, 14 Aug 2005 16:13:03 UTC)

DATE_W3C

World Wide Web Consortium (example: 2005-0814T16:13:03+0000)

PHP Directory Functions
PHP Directory Introduction
The directory functions allow you to retrieve information about directories and their contents.

Installation
The directory functions are part of the PHP core. There is no installation needed to use these
functions.

PHP

PHP Directory Functions
Function

Description

PHP

chdir()

Changes the current directory

3

chroot()

Changes the root directory of the current process

4

dir()

Opens a directory handle and returns an object

3

closedir()

Closes a directory handle

3

getcwd()

Returns the current directory

4

opendir()

Opens a directory handle

3

readdir()

Returns an entry from a directory handle

3

rewinddir()

Resets a directory handle

3

scandir()

Lists files and directories inside a specified path

5

PHP Directory Constants
Constant

Description

PHP

DIRECTORY_SEPARATOR

3

PATH_SEPARATOR

4

PHP Error and Logging Functions
PHP Error and Logging Introduction
The error and logging functions allows error handling and logging.
The error functions allow users to define error handling rules, and modify the way the errors can be
logged.
The logging functions allow users to log applications and send log messages to email, system logs or
other machines.

Installation
The error and logging functions are part of the PHP core. There is no installation needed to use these
functions.

PHP Error and Logging Functions

Function

Description

PHP

debug_backtrace()

Generates a backtrace

4

debug_print_backtrace()

Prints a backtrace

5

error_get_last()

Gets the last error occurred

5

error_log()

Sends an error to the server error-log, to a file or to a
remote destination

4

error_reporting()

Specifies which errors are reported

4

restore_error_handler()

Restores the previous error handler

4

restore_exception_handler()

Restores the previous exception handler

5

set_error_handler()

Sets a user-defined function to handle errors

4

set_exception_handler()

Sets a user-defined function to handle exceptions

5

trigger_error()

Creates a user-defined error message

4

user_error()

Alias of trigger_error()

4

PHP Error and Logging Constants
Value Constant

Description

PHP

1

E_ERROR

Fatal run-time errors. Errors that cannot be recovered
from. Execution of the script is halted

2

E_WARNING

Non-fatal run-time errors. Execution of the script is
not halted

4

E_PARSE

Compile-time parse errors. Parse errors should only be
generated by the parser

8

E_NOTICE

Run-time notices. The script found something that
might be an error, but could also happen when
running a script normally

16

E_CORE_ERROR

Fatal errors at PHP startup. This is like an E_ERROR in 4
the PHP core

32

E_CORE_WARNING

Non-fatal errors at PHP startup. This is like an
E_WARNING in the PHP core

4

64

E_COMPILE_ERROR

Fatal compile-time errors. This is like an E_ERROR
generated by the Zend Scripting Engine

4

128

E_COMPILE_WARNING

Non-fatal compile-time errors. This is like an
E_WARNING generated by the Zend Scripting Engine

4

256

E_USER_ERROR

Fatal user-generated error. This is like an E_ERROR
set by the programmer using the PHP function
trigger_error()

4

512

E_USER_WARNING

Non-fatal user-generated warning. This is like an
E_WARNING set by the programmer using the PHP
function trigger_error()

4

1024

E_USER_NOTICE

User-generated notice. This is like an E_NOTICE set by 4
the programmer using the PHP function trigger_error()

2048

E_STRICT

Run-time notices. PHP suggest changes to your code
to help interoperability and compatibility of the code

5

4096

E_RECOVERABLE_ERROR

Catchable fatal error. This is like an E_ERROR but can
be caught by a user defined handle (see also
set_error_handler())

5

6143

E_ALL

All errors and warnings, except of level E_STRICT

5

PHP Filesystem Functions
PHP Filesystem Introduction
The filesystem functions allow you to access and manipulate the filesystem.

Installation
The filesystem functions are part of the PHP core. There is no installation needed to use these
functions.

The behavior of the filesystem functions is affected by settings in php.ini.
Filesystem configuration options:
Name

Default

Description

Changeable

allow_url_fopen

"1"

Allows fopen()-type functions to work
with URLs (available since PHP 4.0.4)

PHP_INI_SYSTEM

user_agent

NULL

Defines the user agent for PHP to send
(available since PHP 4.3)

PHP_INI_ALL

default_socket_timeout

"60"

Sets the default timeout, in seconds, for PHP_INI_ALL
socket based streams (available since
PHP 4.3)

from

""

Defines the anonymous FTP password
(your email address)

auto_detect_line_endings "0"

PHP_INI_ALL

When set to "1", PHP will examine the
PHP_INI_ALL
data read by fgets() and file() to see if it
is using Unix, MS-Dos or Mac lineending characters (available since PHP
4.3)

Unix / Windows Compatibility
When specifying a path on Unix platforms, the forward slash (/) is used as directory separator.
However, on Windows platforms, both forward slash (/) and backslash () can be used.

PHP Filesystem Functions
Function

Description

PHP

basename()

Returns the filename component of a path

3

chgrp()

Changes the file group

3

chmod()

Changes the file mode

3

chown()

Changes the file owner

3

clearstatcache()

Clears the file status cache

3

copy()

Copies a file

3

delete()

See unlink() or unset()

dirname()

Returns the directory name component of a path

3

disk_free_space()

Returns the free space of a directory

4

disk_total_space()

Returns the total size of a directory

4

diskfreespace()

Alias of disk_free_space()

3

fclose()

Closes an open file

3

feof()

Tests for end-of-file on an open file

3

fflush()

Flushes buffered output to an open file

4

fgetc()

Returns a character from an open file

3

fgetcsv()

Parses a line from an open file, checking for CSV fields

3

fgets()

Returns a line from an open file

3

fgetss()

Returns a line, with HTML and PHP tags removed, from an open
file

3

file()

Reads a file into an array

3

file_exists()

Checks whether or not a file or directory exists

3

file_get_contents()

Reads a file into a string

4

file_put_contents

Writes a string to a file

5

fileatime()

Returns the last access time of a file

3

filectime()

Returns the last change time of a file

3

filegroup()

Returns the group ID of a file

3

fileinode()

Returns the inode number of a file

3

filemtime()

Returns the last modification time of a file

3

fileowner()

Returns the user ID (owner) of a file

3

fileperms()

Returns the permissions of a file

3

filesize()

Returns the file size

3

filetype()

Returns the file type

3

flock()

Locks or releases a file

3

fnmatch()

Matches a filename or string against a specified pattern

4

fopen()

Opens a file or URL

3

fpassthru()

Reads from an open file, until EOF, and writes the result to the
output buffer

3

fputcsv()

Formats a line as CSV and writes it to an open file

5

fputs()

Alias of fwrite()

3

fread()

Reads from an open file

3

fscanf()

Parses input from an open file according to a specified format

4

fseek()

Seeks in an open file

3

fstat()

Returns information about an open file

4

ftell()

Returns the current position in an open file

3

ftruncate()

Truncates an open file to a specified length

4

fwrite()

Writes to an open file

3

glob()

Returns an array of filenames / directories matching a specified
pattern

4

is_dir()

Checks whether a file is a directory

3

is_executable()

Checks whether a file is executable

3

is_file()

Checks whether a file is a regular file

3

is_link()

Checks whether a file is a link

3

is_readable()

Checks whether a file is readable

3

is_uploaded_file()

Checks whether a file was uploaded via HTTP POST

3

is_writable()

Checks whether a file is writeable

4

is_writeable()

Alias of is_writable()

3

link()

Creates a hard link

3

linkinfo()

Returns information about a hard link

3

lstat()

Returns information about a file or symbolic link

3

mkdir()

Creates a directory

3

move_uploaded_file()

Moves an uploaded file to a new location

4

parse_ini_file()

Parses a configuration file

4

pathinfo()

Returns information about a file path

4

pclose()

Closes a pipe opened by popen()

3

popen()

Opens a pipe

3

readfile()

Reads a file and writes it to the output buffer

3

readlink()

Returns the target of a symbolic link

3

realpath()

Returns the absolute pathname

4

rename()

Renames a file or directory

3

rewind()

Rewinds a file pointer

3

rmdir()

Removes an empty directory

3

set_file_buffer()

Sets the buffer size of an open file

3

stat()

Returns information about a file

3

symlink()

Creates a symbolic link

3

tempnam()

Creates a unique temporary file

3

tmpfile()

Creates a unique temporary file

3

touch()

Sets access and modification time of a file

3

umask()

Changes file permissions for files

3

unlink()

Deletes a file

3

PHP Filesystem Constants
Constant

Description

PHP

GLOB_BRACE
GLOB_ONLYDIR
GLOB_MARK
GLOB_NOSORT
GLOB_NOCHECK
GLOB_NOESCAPE
PATHINFO_DIRNAME
PATHINFO_BASENAME
PATHINFO_EXTENSION
FILE_USE_INCLUDE_PATH
FILE_APPEND
FILE_IGNORE_NEW_LINES
FILE_SKIP_EMPTY_LINES

PHP Filter Functions
PHP Filter Introduction
This PHP filters is used to validate and filter data coming from insecure sources, like user input.

Installation
The filter functions are part of the PHP core. There is no installation needed to use these functions.

PHP Filter Functions
Function

Description

PHP

filter_has_var()

Checks if a variable of a specified input type exist

5

filter_id()

Returns the ID number of a specified filter

5

filter_input()

Get input from outside the script and filter it

5

filter_input_array()

Get multiple inputs from outside the script and filters them

5

filter_list()

Returns an array of all supported filters

5

filter_var_array()

Get multiple variables and filter them

5

filter_var()

Get a variable and filter it

5

PHP Filters
ID Name

Description

FILTER_CALLBACK

Call a user-defined function to filter data

FILTER_SANITIZE_STRING

Strip tags, optionally strip or encode special
characters

FILTER_SANITIZE_STRIPPED

Alias of "string" filter

FILTER_SANITIZE_ENCODED

URL-encode string, optionally strip or encode
special characters

FILTER_SANITIZE_SPECIAL_CHARS

HTML-escape '"<>& and characters with ASCII
value less than 32

FILTER_SANITIZE_EMAIL

Remove all characters, except letters, digits and
!#$%&'*+-/=?^_`{|}~@.[]

FILTER_SANITIZE_URL

Remove all characters, except letters, digits and
$-_.+!*'(),{}|^~[]`<>#%";/?:@&=

FILTER_SANITIZE_NUMBER_INT

Remove all characters, except digits and +-

FILTER_SANITIZE_NUMBER_FLOAT

Remove all characters, except digits, +- and
optionally .,eE

FILTER_SANITIZE_MAGIC_QUOTES

Apply addslashes()

FILTER_UNSAFE_RAW

Do nothing, optionally strip or encode special
characters

FILTER_VALIDATE_INT

Validate value as integer, optionally from the
specified range

FILTER_VALIDATE_BOOLEAN

Return TRUE for "1", "true", "on" and "yes", FALSE
for "0", "false", "off", "no", and "", NULL otherwise

FILTER_VALIDATE_FLOAT

Validate value as float

FILTER_VALIDATE_REGEXP

Validate value against regexp, a Perl-compatible
regular expression

FILTER_VALIDATE_URL

Validate value as URL, optionally with required
components

FILTER_VALIDATE_EMAIL

Validate value as e-mail

FILTER_VALIDATE_IP

Validate value as IP address, optionally only IPv4
or IPv6 or not from private or reserved ranges

PHP FTP Functions
PHP FTP Introduction

The FTP functions give client access to file servers through the File Transfer Protocol (FTP).
The FTP functions are used to open, login and close connections, as well as upload, download,
rename, delete, and get information on files from file servers. Not all of the FTP functions will work
with every server or return the same results. The FTP functions became available with PHP 3.
These functions are meant for detailed access to an FTP server. If you only wish to read from or write
to a file on an FTP server, consider using the ftp:// wrapper with the Filesystem functions.

Installation
The windows version of PHP has built-in support for the FTP extension. So, the FTP functions will work
automatically.
However, if you are running the Linux version of PHP, you will have to compile PHP with --enable-ftp
(PHP 4+) or --with-ftp (PHP 3) to get the FTP functions to work.

PHP FTP Functions
Function

Description

PHP

ftp_alloc()

Allocates space for a file to be uploaded to the FTP server

5

ftp_cdup()

Changes the current directory to the parent directory on the FTP
server

3

ftp_chdir()

Changes the current directory on the FTP server

3

ftp_chmod()

Sets permissions on a file via FTP

5

ftp_close()

Closes an FTP connection

4

ftp_connect()

Opens an FTP connection

3

ftp_delete()

Deletes a file on the FTP server

3

ftp_exec()

Executes a program/command on the FTP server

4

ftp_fget()

Downloads a file from the FTP server and saves it to an open file

3

ftp_fput()

Uploads from an open file and saves it to a file on the FTP server

3

ftp_get_option()

Returns runtime behaviors of the FTP connection

4

ftp_get()

Downloads a file from the FTP server

3

ftp_login()

Logs on to an FTP connection

3

ftp_mdtm()

Returns the last modified time of a specified file

3

ftp_mkdir()

Creates a new directory on the FTP server

3

ftp_nb_continue()

Continues retrieving/sending a file (non-blocking)

4

ftp_nb_fget()

Downloads a file from the FTP server and saves it to an open file
(non-blocking)

4

ftp_nb_fput()

Uploads from an open file and saves it to a file on the FTP server
(non-blocking)

4

ftp_nb_get()

Downloads a file from the FTP server (non-blocking)

4

ftp_nb_put()

Uploads a file to the FTP server (non-blocking)

4

ftp_nlist()

Lists the files in a specified directory on the FTP server

3

ftp_pasv()

Turns passive mode on or off

3

ftp_put()

Uploads a file to the FTP server

3

ftp_pwd()

Returns the current directory name

3

ftp_quit()

Alias of ftp_close()

3

ftp_raw()

Sends a raw command to the FTP server

5

ftp_rawlist()

Returns a detailed list of files in the specified directory

3

ftp_rename()

Renames a file or directory on the FTP server

3

ftp_rmdir()

Removes a directory on the FTP server

3

ftp_set_option()

Sets runtime options for the FTP connection

4

ftp_site()

Sends a SITE command to the server

3

ftp_size()

Returns the size of the specified file

3

ftp_ssl_connect()

Opens a secure SSL-FTP connection

4

ftp_systype()

Returns the system type identifier of the FTP server

3

PHP FTP Constants
Constant

Description

PHP

FTP_ASCII

3

FTP_TEXT

3

FTP_BINARY

3

FTP_IMAGE

3

FTP_TIMEOUT_SEC

3

FTP_AUTOSEEK

4

FTP_AUTORESUME

Determine resume position and start position for get and put
requests automatically

4

FTP_FAILED

Asynchronous transfer has failed

4

FTP_FINISHED

Asynchronous transfer has finished

4

FTP_MOREDATA

Asynchronous transfer is still active

4

PHP HTTP Functions

PHP HTTP Introduction
The HTTP functions let you manipulate information sent to the browser by the Web server, before any
other output has been sent.

Installation
The directory functions are part of the PHP core. There is no installation needed to use these
functions.

PHP HTTP Functions
Function

Description

PHP

header()

Sends a raw HTTP header to a client

3

headers_list()

Returns a list of response headers sent (or ready to send) 5

headers_sent()

Checks if / where the HTTP headers have been sent

3

setcookie()

Sends an HTTP cookie to a client

3

setrawcookie()

Sends an HTTP cookie without URL encoding the cookie
value

5

PHP HTTP Constants

PHP libxml Functions
PHP libxml Introduction
The libxml functions and constants are used together with SimpleXML, XSLT and DOM functions.

Installation
These functions require the libxml package. Download at xmlsoft.org

PHP libxml Functions
Function

Description

PHP

libxml_clear_errors()

Clear libxml error buffer

5

libxml_get_errors()

Retrieve array of errors

5

libxml_get_last_error()

Retrieve last error from libxml

5

libxml_set_streams_context()

Set the streams context for the next libxml document
load or write

5

libxml_use_internal_errors()

Disable libxml errors and allow user to fetch error
information as needed

5

Function

Description

PHP

LIBXML_COMPACT

Set small nodes allocation optimization. This may
improve the application performance

5

LIBXML_DTDATTR

Set default DTD attributes

5

LIBXML_DTDLOAD

Load external subset

5

LIBXML_DTDVALID

Validate with the DTD

5

LIBXML_NOBLANKS

Remove blank nodes

5

LIBXML_NOCDATA

Set CDATA as text nodes

5

LIBXML_NOEMPTYTAG

Change empty tags (e.g. <br/> to <br></br>), only
available in the DOMDocument->save() and
DOMDocument->saveXML() functions

5

LIBXML_NOENT

Substitute entities

5

LIBXML_NOERROR

Do not show error reports

5

LIBXML_NONET

Stop network access while loading documents

5

LIBXML_NOWARNING

Do not show warning reports

5

LIBXML_NOXMLDECL

Drop the XML declaration when saving a document

5

LIBXML_NSCLEAN

Remove excess namespace declarations

5

LIBXML_XINCLUDE

Use XInclude substitution

5

LIBXML_ERR_ERROR

Get recoverable errors

5

LIBXML_ERR_FATAL

Get fatal errors

5

LIBXML_ERR_NONE

Get no errors

5

LIBXML_ERR_WARNING

Get simple warnings

5

LIBXML_VERSION

Get libxml version (e.g. 20605 or 20617)

5

LIBXML_DOTTED_VERSION

Get dotted libxml version (e.g. 2.6.5 or 2.6.17)

5

PHP libxml Constants

PHP Mail Functions
PHP Mail Introduction
The mail() function allows you to send emails directly from a script.

Requirements
For the mail functions to be available, PHP requires an installed and working email system. The
program to be used is defined by the configuration settings in the php.ini file.

Installation
The mail functions are part of the PHP core. There is no installation needed to use these functions.

The behavior of the mail functions is affected by settings in the php.ini file.
Mail configuration options:
Name

Default

Description

Changeable

SMTP

"localhost"

Windows only: The DNS name or IP
address of the SMTP server

PHP_INI_ALL

smtp_port

"25"

Windows only: The SMTP port number.
Available since PHP 4.3

PHP_INI_ALL

sendmail_from

NULL

Windows only: Specifies the "from"
PHP_INI_ALL
address to be used in email sent from PHP

sendmail_path

NULL

Unix systems only: Specifies where the
sendmail program can be found (usually
/usr/sbin/sendmail or /usr/lib/sendmail)

PHP_INI_SYSTEM

PHP Mail Functions
Function

Description

PHP

ezmlm_hash()

Calculates the hash value needed by the EZMLM mailing list system

3

mail()

Allows you to send emails directly from a script

3

PHP Mail Constants

PHP Math Functions
PHP Math Introduction
The math functions can handle values within the range of integer and float types.

Installation
The math functions are part of the PHP core. There is no installation needed to use these functions.

PHP Math Functions
Function

Description

PHP

abs()

Returns the absolute value of a number

3

acos()

Returns the arccosine of a number

3

acosh()

Returns the inverse hyperbolic cosine of a number

4

asin()

Returns the arcsine of a number

3

asinh()

Returns the inverse hyperbolic sine of a number

4

atan()

Returns the arctangent of a number as a numeric value between - 3
PI/2 and PI/2 radians

atan2()

Returns the angle theta of an (x,y) point as a numeric value
between -PI and PI radians

3

atanh()

Returns the inverse hyperbolic tangent of a number

4

base_convert()

Converts a number from one base to another

3

bindec()

Converts a binary number to a decimal number

3

ceil()

Returns the value of a number rounded upwards to the nearest
integer

3

cos()

Returns the cosine of a number

3

cosh()

Returns the hyperbolic cosine of a number

4

decbin()

Converts a decimal number to a binary number

3

dechex()

Converts a decimal number to a hexadecimal number

3

decoct()

Converts a decimal number to an octal number

3

deg2rad()

Converts a degree to a radian number

3

exp()

3

x

Returns the value of E

x

4

expm1()

Returns the value of E - 1

floor()

Returns the value of a number rounded downwards to the nearest 3
integer

fmod()

Returns the remainder (modulo) of the division of the arguments

4

getrandmax()

Returns the maximum random number that can be returned by a
call to the rand() function

3

hexdec()

Converts a hexadecimal number to a decimal number

3

hypot()

Returns the length of the hypotenuse of a right-angle triangle

4

is_finite()

Returns true if a value is a finite number

4

is_infinite()

Returns true if a value is an infinite number

4

is_nan()

Returns true if a value is not a number

4

lcg_value()

Returns a pseudo random number in the range of (0,1)

4

log()

Returns the natural logarithm (base E) of a number

3

log10()

Returns the base-10 logarithm of a number

3

log1p()

Returns log(1+number)

4

max()

Returns the number with the highest value of two specified
numbers

3

min()

Returns the number with the lowest value of two specified
numbers

3

mt_getrandmax()

Returns the largest possible value that can be returned by
mt_rand()

3

mt_rand()

Returns a random integer using Mersenne Twister algorithm

3

mt_srand()

Seeds the Mersenne Twister random number generator

3

octdec()

Converts an octal number to a decimal number

3

pi()

Returns the value of PI

3

pow()

Returns the value of x to the power of y

3

rad2deg()

Converts a radian number to a degree

3

rand()

Returns a random integer

3

round()

Rounds a number to the nearest integer

3

sin()

Returns the sine of a number

3

sinh()

Returns the hyperbolic sine of a number

4

sqrt()

Returns the square root of a number

3

srand()

Seeds the random number generator

3

tan()

Returns the tangent of an angle

3

tanh()

Returns the hyperbolic tangent of an angle

4

PHP Math Constants
Constant

Description

PHP

M_E

Returns e (approx. 2.718)

4

M_EULER

Returns Euler's constant (approx. 0.577)

4

M_LNPI

Returns the natural logarithm of PI (approx. 1.144)

4

M_LN2

Returns the natural logarithm of 2 (approx. 0.693)

4

M_LN10

Returns the natural logarithm of 10 (approx. 2.302)

4

M_LOG2E

Returns the base-2 logarithm of E (approx. 1.442)

4

M_LOG10E

Returns the base-10 logarithm of E (approx. 0.434)

4

M_PI

Returns PI (approx. 3.14159)

3

M_PI_2

Returns PI/2 (approx. 1.570)

4

M_PI_4

Returns PI/4 (approx. 0.785)

4

M_1_PI

Returns 1/PI (approx. 0.318)

4

M_2_PI

Returns 2/PI (approx. 0.636)

4

M_SQRTPI

Returns the square root of PI (approx. 1.772)

4

M_2_SQRTPI

Returns 2/square root of PI (approx. 1.128)

4

M_SQRT1_2

Returns the square root of 1/2 (approx. 0.707)

4

M_SQRT2

Returns the square root of 2 (approx. 1.414)

4

M_SQRT3

Returns the square root of 3 (approx. 1.732)

4

PHP Misc. Functions

PHP Miscellaneous Introduction
The misc. functions were only placed here because none of the other
categories seemed to fit.

Installation
The misc functions are part of the PHP core. There is no installation needed
to use these functions.

The behavior of the misc functions is affected by settings in the php.ini file.
Misc. configuration options:
Name
Default
ignore_user_abort "0"

highlight.string

"#DD0000"

highlight.comment "#FF8000"
highlight.keyword "#007700"

highlight.bg
highlight.default
highlight.html
browscap

"#FFFFFF"
"#0000BB"
"#000000"
NULL

Description
FALSE indicates that scripts will be
terminated as soon as they try to output
something after a client has aborted
their connection
Color for highlighting a string in PHP
syntax
Color for highlighting PHP comments
Color for syntax highlighting PHP
keywords (e.g. parenthesis and
semicolon)
Color for background
Default color for PHP syntax
Color for HTML code
Name and location of browsercapabilities file (e.g. browscap.ini)

Changeable
PHP_INI_ALL

PHP_INI_ALL
PHP_INI_ALL
PHP_INI_ALL

PHP_INI_ALL
PHP_INI_ALL
PHP_INI_ALL
PHP_INI_SYSTEM

PHP Misc. Functions
Function
connection_aborted()
connection_status()
connection_timeout()
constant()
define()
defined()
die()
eval()
exit()
get_browser()
highlight_file()
highlight_string()
ignore_user_abort()
pack()
php_check_syntax()
php_strip_whitespace()
show_source()
sleep()
time_nanosleep()
time_sleep_until()
uniqid()
unpack()
usleep()

Description
Checks whether the client has disconnected
Returns the current connection status
Deprecated in PHP 4.0.5
Returns the value of a constant
Defines a constant
Checks whether a constant exists
Prints a message and exits the current script
Evaluates a string as PHP code
Prints a message and exits the current script
Returns the capabilities of the user's browser
Outputs a file with the PHP syntax highlighted
Outputs a string with the PHP syntax highlighted
Sets whether a remote client can abort the running of a script
Packs data into a binary string
Deprecated in PHP 5.0.5
Returns the source code of a file with PHP comments and
whitespace removed
Alias of highlight_file()
Delays code execution for a number of seconds
Delays code execution for a number of seconds and
nanoseconds
Delays code execution until a specified time
Generates a unique ID
Unpacks data from a binary string
Delays code execution for a number of microseconds

PHP
3
3
3
4
3
3
3
3
3
3
4
4
3
3
5
5
4
3
5
5
3
3
3

PHP Misc. Constants
Constant
Description
CONNECTION_ABORTED
CONNECTION_NORMAL
CONNECTION_TIMEOUT
__COMPILER_HALT_OFFSET__

PHP

5

PHP MySQL Functions
PHP MySQL Introduction
The MySQL functions allows you to access MySQL database servers.

Installation
For the MySQL functions to be available, you must compile PHP with MySQL support.
For compiling, use --with-mysql=DIR (the optional DIR points to the MySQL directory).
Note: For full functionality of MySQL versions greater than 4.1., use the MySQLi extension instead. If
you would like to install both the mysql extension and the mysqli extension you should use the same
client library to avoid any conflicts.
Installation on Linux Systems
PHP 5+: MySQL and the MySQL library is not enabled by default. Use the --with-mysql=DIR configure
option to include MySQL support and download headers and libraries from www.mysql.com.
Installation on Windows Systems
PHP 5+: MySQL is not enabled by default, so the php_mysql.dll must be enabled inside of php.ini.
Also, PHP needs access to the MySQL client library. A file named libmysql.dll is included in the
Windows PHP distribution, and in order for PHP to talk to MySQL this file needs to be available to the
Windows systems PATH.
To enable any PHP extension, the PHP extension_dir setting (in the php.ini file) should be set to the
directory where the PHP extensions are located. An example extension_dir value is c:phpext.
Note: If you get the following error when starting the web server: "Unable to load dynamic library
'./php_mysql.dll'", this is because php_mysql.dll or libmysql.dll cannot be found by the system.

The behavior of the MySQL functions is affected by settings in the php.ini file.
MySQL configuration options:
Name

Default

Description

Changeable

mysql.allow_persistent

"1"

Whether or not to allow persistent
connections

PHP_INI_SYSTEM

mysql.max_persistent

"-1"

The maximum number of persistent
connections per process

PHP_INI_SYSTEM

mysql.max_links

"-1"

The maximum number of connections
per process (persistent connections
included)

PHP_INI_SYSTEM

mysql.trace_mode

"0"

Trace mode. When set to "1", warnings
and SQL-errors will be displayed.
Available since PHP 4.3

PHP_INI_ALL

mysql.default_port

NULL

The default TCP port number to use

PHP_INI_ALL

mysql.default_socket

NULL

The default socket name to use.
Available since PHP 4.0.1

PHP_INI_ALL

mysql.default_host

NULL

The default server host to use (doesn't
apply in SQL safe mode)

PHP_INI_ALL

mysql.default_user

NULL

The default user name to use (doesn't

PHP_INI_ALL

mysql.default_password NULL

The default password to use (doesn't

PHP_INI_ALL

mysql.connect_timeout "60"

Connection timeout in seconds

PHP_INI_ALL

Resource Types
There are two resource types used in the MySQL extension. The first one is the link_identifier for a
database connection, the second is a resource which holds the result of a query.
Note: Most MySQL functions accept link_identifier as the last optional parameter. If it is not provided,
the last opened connection is used.

PHP MySQL Functions
Function

Description

PHP

mysql_affected_rows()

Returns the number of affected rows in the previous MySQL
operation

3

mysql_change_user()

Deprecated. Changes the user of the current MySQL
connection

3

mysql_client_encoding()

Returns the name of the character set for the current
connection

4

mysql_close()

Closes a non-persistent MySQL connection

3

mysql_connect()

Opens a non-persistent MySQL connection

3

mysql_create_db()

Deprecated. Creates a new MySQL database. Use
mysql_query() instead

3

mysql_data_seek()

Moves the record pointer

3

mysql_db_name()

Returns a database name from a call to mysql_list_dbs()

3

mysql_db_query()

Deprecated. Sends a MySQL query. Use mysql_select_db()
and mysql_query() instead

3

mysql_drop_db()

Deprecated. Deletes a MySQL database. Use mysql_query()
instead

3

mysql_errno()

Returns the error number of the last MySQL operation

3

mysql_error()

Returns the error description of the last MySQL operation

3

mysql_escape_string()

Deprecated. Escapes a string for use in a mysql_query. Use
mysql_real_escape_string() instead

4

mysql_fetch_array()

Returns a row from a recordset as an associative array
and/or a numeric array

3

mysql_fetch_assoc()

Returns a row from a recordset as an associative array

4

mysql_fetch_field()

Returns column info from a recordset as an object

3

mysql_fetch_lengths()

Returns the length of the contents of each field in a result
row

3

mysql_fetch_object()

Returns a row from a recordset as an object

3

mysql_fetch_row()

Returns a row from a recordset as a numeric array

3

mysql_field_flags()

Returns the flags associated with a field in a recordset

3

mysql_field_len()

Returns the maximum length of a field in a recordset

3

mysql_field_name()

Returns the name of a field in a recordset

3

mysql_field_seek()

Moves the result pointer to a specified field

3

mysql_field_table()

Returns the name of the table the specified field is in

3

mysql_field_type()

Returns the type of a field in a recordset

3

mysql_free_result()

Free result memory

3

mysql_get_client_info()

Returns MySQL client info

4

mysql_get_host_info()

Returns MySQL host info

4

mysql_get_proto_info()

Returns MySQL protocol info

4

mysql_get_server_info()

Returns MySQL server info

4

mysql_info()

Returns information about the last query

4

mysql_insert_id()

Returns the AUTO_INCREMENT ID generated from the
previous INSERT operation

3

mysql_list_dbs()

Lists available databases on a MySQL server

3

mysql_list_fields()

Deprecated. Lists MySQL table fields. Use mysql_query()
instead

3

mysql_list_processes()

Lists MySQL processes

4

mysql_list_tables()

Deprecated. Lists tables in a MySQL database. Use

3

mysql_num_fields()

Returns the number of fields in a recordset

3

mysql_num_rows()

Returns the number of rows in a recordset

3

mysql_pconnect()

Opens a persistent MySQL connection

3

mysql_ping()

Pings a server connection or reconnects if there is no
connection

4

mysql_query()

Executes a query on a MySQL database

3

mysql_real_escape_string()

Escapes a string for use in SQL statements

4

mysql_result()

Returns the value of a field in a recordset

3

mysql_select_db()

Sets the active MySQL database

3

mysql_stat()

Returns the current system status of the MySQL server

4

mysql_tablename()

Deprecated. Returns the table name of field. Use

3

mysql_thread_id()

Returns the current thread ID

4

mysql_unbuffered_query()

Executes a query on a MySQL database (without fetching /
buffering the result)

4

PHP MySQL Constants
Since PHP 4.3 it has been possible to specify additional flags for the mysql_connect() and
mysql_pconnect() functions:
Constant

Description

PHP

MYSQL_CLIENT_COMPRESS

Use compression protocol

4.3

MYSQL_CLIENT_IGNORE_SPACE

Allow space after function names

4.3

MYSQL_CLIENT_INTERACTIVE

Allow interactive timeout seconds of inactivity
before closing the connection

4.3

MYSQL_CLIENT_SSL

Use SSL encryption (only available with version
4+ of the MySQL client library)

4.3

The mysql_fetch_array() function uses a constant for the different types of result arrays. The following
constants are defined:
Constant

Description

MYSQL_ASSOC

Columns are returned into the array with the fieldname as the array
index

MYSQL_BOTH

Columns are returned into the array having both a numerical index and
the fieldname as the array index

MYSQL_NUM

PHP

Columns are returned into the array having a numerical index (index
starts at 0)

PHP SimpleXML Functions
PHP SimpleXML Introduction
The SimpleXML functions lets you convert XML to an object.
This object can be processed, like any other object, with normal property selectors and array iterators.
Some of these functions requires the newest PHP build.

Installation

The SimpleXML functions are part of the PHP core. There is no installation needed to use these
functions.

PHP SimpleXML Functions
Function

Description

PHP

__construct()

Creates a new SimpleXMLElement object

5

addAttribute()

Adds an attribute to the SimpleXML element

5

addChild()

Adds a child element the SimpleXML element

5

asXML()

Gets an XML string from a SimpleXML element

5

attributes()

Gets a SimpleXML element's attributes

5

children()

Gets the children of a specified node

5

getDocNamespaces()

Gets the namespaces of an XML document

5

getName()

Gets the name of a SimpleXML element

5

getNamespaces()

Gets the namespaces from XML data

5

registerXPathNamespace()

Creates a namespace context for the next XPath query

5

simplexml_import_dom()

Gets a SimpleXMLElement object from a DOM node

5

simplexml_load_file()

Gets a SimpleXMLElement object from an XML document

5

simplexml_load_string()

Gets a SimpleXMLElement object from an XML string

5

xpath()

Runs an XPath query on XML data

PHP String Functions
PHP String Introduction
The string functions allow you to manipulate strings.

Installation
The string functions are part of the PHP core. There is no installation needed to use these functions.

PHP String Functions
Function

Description

PHP

addcslashes()

Returns a string with backslashes in front of the specified 4
characters

addslashes()

Returns a string with backslashes in front of predefined

3

characters
bin2hex()

Converts a string of ASCII characters to hexadecimal
values

3

chop()

Alias of rtrim()

3

chr()

Returns a character from a specified ASCII value

3

chunk_split()

Splits a string into a series of smaller parts

3

convert_cyr_string()

Converts a string from one Cyrillic character-set to
another

3

convert_uudecode()

Decodes a uuencoded string

5

convert_uuencode()

Encodes a string using the uuencode algorithm

5

count_chars()

Returns how many times an ASCII character occurs
within a string and returns the information

4

crc32()

Calculates a 32-bit CRC for a string

4

crypt()

One-way string encryption (hashing)

3

echo()

Outputs strings

3

explode()

Breaks a string into an array

3

fprintf()

Writes a formatted string to a specified output stream

5

get_html_translation_table()

Returns the translation table used by htmlspecialchars()
and htmlentities()

4

hebrev()

Converts Hebrew text to visual text

3

hebrevc()

Converts Hebrew text to visual text and new lines (n)
into <br />

3

html_entity_decode()

Converts HTML entities to characters

4

htmlentities()

Converts characters to HTML entities

3

htmlspecialchars_decode()

Converts some predefined HTML entities to characters

5

htmlspecialchars()

Converts some predefined characters to HTML entities

3

implode()

Returns a string from the elements of an array

3

join()

Alias of implode()

3

levenshtein()

Returns the Levenshtein distance between two strings

3

localeconv()

Returns locale numeric and monetary formatting
information

4

ltrim()

Strips whitespace from the left side of a string

3

md5()

Calculates the MD5 hash of a string

3

md5_file()

Calculates the MD5 hash of a file

4

metaphone()

Calculates the metaphone key of a string

4

money_format()

Returns a string formatted as a currency string

4

nl_langinfo()

Returns specific local information

4

nl2br()

Inserts HTML line breaks in front of each newline in a
string

3

number_format()

Formats a number with grouped thousands

3

ord()

Returns the ASCII value of the first character of a string

3

parse_str()

Parses a query string into variables

3

print()

Outputs a string

3

printf()

Outputs a formatted string

3

quoted_printable_decode()

Decodes a quoted-printable string

3

quotemeta()

Quotes meta characters

3

rtrim()

Strips whitespace from the right side of a string

3

setlocale()

Sets locale information

3

sha1()

Calculates the SHA-1 hash of a string

4

sha1_file()

Calculates the SHA-1 hash of a file

4

similar_text()

Calculates the similarity between two strings

3

soundex()

Calculates the soundex key of a string

3

sprintf()

Writes a formatted string to a variable

3

sscanf()

Parses input from a string according to a format

4

str_ireplace()

Replaces some characters in a string (case-insensitive)

5

str_pad()

Pads a string to a new length

4

str_repeat()

Repeats a string a specified number of times

4

str_replace()

Replaces some characters in a string (case-sensitive)

3

str_rot13()

Performs the ROT13 encoding on a string

4

str_shuffle()

Randomly shuffles all characters in a string

4

str_split()

Splits a string into an array

5

str_word_count()

Count the number of words in a string

4

strcasecmp()

Compares two strings (case-insensitive)

3

strchr()

Finds the first occurrence of a string inside another string 3
(alias of strstr())

strcmp()

Compares two strings (case-sensitive)

3

strcoll()

Locale based string comparison

4

strcspn()

Returns the number of characters found in a string before 3
any part of some specified characters are found

strip_tags()

Strips HTML and PHP tags from a string

3

stripcslashes()

Unquotes a string quoted with addcslashes()

4

stripslashes()

Unquotes a string quoted with addslashes()

3

stripos()

Returns the position of the first occurrence of a string
inside another string (case-insensitive)

5

stristr()

(case-insensitive)

strlen()

Returns the length of a string

3

strnatcasecmp()

Compares two strings using a "natural order" algorithm
(case-insensitive)

4

strnatcmp()

Compares two strings using a "natural order" algorithm
(case-sensitive)

4

strncasecmp()

String comparison of the first n characters (caseinsensitive)

4

strncmp()

String comparison of the first n characters (casesensitive)

4

strpbrk()

Searches a string for any of a set of characters

5

strpos()

Returns the position of the first occurrence of a string
inside another string (case-sensitive)

3

strrchr()

Finds the last occurrence of a string inside another string

3

strrev()

Reverses a string

3

strripos()

Finds the position of the last occurrence of a string inside 5
another string (case-insensitive)

strrpos()

Finds the position of the last occurrence of a string inside 3
another string (case-sensitive)

strspn()

Returns the number of characters found in a string that
contains only characters from a specified charlist

strstr()

(case-sensitive)

strtok()

Splits a string into smaller strings

3

strtolower()

Converts a string to lowercase letters

3

strtoupper()

Converts a string to uppercase letters

3

strtr()

Translates certain characters in a string

3

substr()

Returns a part of a string

3

substr_compare()

Compares two strings from a specified start position
(binary safe and optionally case-sensitive)

5

substr_count()

Counts the number of times a substring occurs in a string 4

substr_replace()

Replaces a part of a string with another string

4

trim()

Strips whitespace from both sides of a string

3

ucfirst()

Converts the first character of a string to uppercase

3

ucwords()

Converts the first character of each word in a string to
uppercase

3

vfprintf()

Writes a formatted string to a specified output stream

5

vprintf()

Outputs a formatted string

4

vsprintf()

Writes a formatted string to a variable

4

wordwrap()

Wraps a string to a given number of characters

4

3

PHP String Constants
Constant

Description

CRYPT_SALT_LENGTH

Contains the length of the default encryption method for
the
system. For standard DES encryption, the length is 2

CRYPT_STD_DES

Set to 1 if the standard DES-based encryption with a 2
character salt is supported, 0 otherwise

CRYPT_EXT_DES

Set to 1 if the extended DES-based encryption with a 9
character salt is supported, 0 otherwise

CRYPT_MD5

Set to 1 if the MD5 encryption with a 12 character salt
starting with $1$ is supported, 0 otherwise

CRYPT_BLOWFISH

Set to 1 if the Blowfish encryption with a 16 character
salt starting with $2$ or $2a$ is supported, 0 otherwise0

HTML_SPECIALCHARS
HTML_ENTITIES

PHP

ENT_COMPAT
ENT_QUOTES
ENT_NOQUOTES
CHAR_MAX
LC_CTYPE
LC_NUMERIC
LC_TIME
LC_COLLATE
LC_MONETARY
LC_ALL
LC_MESSAGES
STR_PAD_LEFT
STR_PAD_RIGHT
STR_PAD_BOTH

PHP XML Parser Functions
PHP XML Parser Introduction
The XML functions lets you parse, but not validate, XML documents.
XML is a data format for standardized structured document exchange. More information on XML can be
found in our XML Tutorial.
This extension uses the Expat XML parser.
Expat is an event-based parser, it views an XML document as a series of events. When an event
occurs, it calls a specified function to handle it.
Expat is a non-validating parser, and ignores any DTDs linked to a document. However, if the
document is not well formed it will end with an error message.
Because it is an event-based, non validating parser, Expat is fast and well suited for web applications.
The XML parser functions lets you create XML parsers and define handlers for XML events.

Installation

The XML functions are part of the PHP core. There is no installation needed to use these functions.

PHP XML Parser Functions
Function

Description

PHP

utf8_decode()

Decodes an UTF-8 string to ISO-8859-1

3

utf8_encode()

Encodes an ISO-8859-1 string to UTF-8

3

xml_error_string()

Gets an error string from the XML parser

3

xml_get_current_byte_index()

Gets the current byte index from the XML
parser

3

xml_get_current_column_number()

Gets the current column number from the
XML parser

3

xml_get_current_line_number()

Gets the current line number from the
XML parser

3

xml_get_error_code()

Gets an error code from the XML parser

3

xml_parse()

Parses an XML document

3

xml_parse_into_struct()

Parse XML data into an array

3

xml_parser_create_ns()

Create an XML parser with namespace
support

4

xml_parser_create()

Create an XML parser

3

xml_parser_free()

Free an XML parser

3

xml_parser_get_option()

Get options from an XML parser

3

xml_parser_set_option()

Set options in an XML parser

3

xml_set_character_data_handler()

Set handler function for character data

3

xml_set_default_handler()

Set default handler function

3

xml_set_element_handler()

Set handler function for start and end
element of elements

3

xml_set_end_namespace_decl_handler()

Set handler function for the end of
namespace declarations

4

xml_set_external_entity_ref_handler()

Set handler function for external entities

3

xml_set_notation_decl_handler()

Set handler function for notation
declarations

3

xml_set_object()

Use XML Parser within an object

4

xml_set_processing_instruction_handler()

Set handler function for processing
instruction

3

xml_set_start_namespace_decl_handler()

Set handler function for the start of
namespace declarations

4

xml_set_unparsed_entity_decl_handler()

Set handler function for unparsed entity
declarations

3

PHP XML Parser Constants

Constant
XML_ERROR_NONE (integer)
XML_ERROR_NO_MEMORY (integer)
XML_ERROR_SYNTAX (integer)
XML_ERROR_NO_ELEMENTS (integer)
XML_ERROR_INVALID_TOKEN (integer)
XML_ERROR_UNCLOSED_TOKEN (integer)
XML_ERROR_PARTIAL_CHAR (integer)
XML_ERROR_TAG_MISMATCH (integer)
XML_ERROR_DUPLICATE_ATTRIBUTE (integer)
XML_ERROR_JUNK_AFTER_DOC_ELEMENT (integer)
XML_ERROR_PARAM_ENTITY_REF (integer)
XML_ERROR_UNDEFINED_ENTITY (integer)
XML_ERROR_RECURSIVE_ENTITY_REF (integer)
XML_ERROR_ASYNC_ENTITY (integer)
XML_ERROR_BAD_CHAR_REF (integer)
XML_ERROR_BINARY_ENTITY_REF (integer)
XML_ERROR_ATTRIBUTE_EXTERNAL_ENTITY_REF (integer)
XML_ERROR_MISPLACED_XML_PI (integer)
XML_ERROR_UNKNOWN_ENCODING (integer)
XML_ERROR_INCORRECT_ENCODING (integer)
XML_ERROR_UNCLOSED_CDATA_SECTION (integer)
XML_ERROR_EXTERNAL_ENTITY_HANDLING (integer)
XML_OPTION_CASE_FOLDING (integer)
XML_OPTION_TARGET_ENCODING (integer)
XML_OPTION_SKIP_TAGSTART (integer)
XML_OPTION_SKIP_WHITE (integer)

PHP Zip File Functions
PHP Zip File Introduction
The Zip files functions allows you to read ZIP files.

Installation
For the Zip file functions to work on your server, these libraries must be installed:
The ZZIPlib library by Guido Draheim: Download the ZZIPlib library
The Zip PELC extension: Download the Zip PELC extension
Installation on Linux Systems

PHP 5+: Zip functions and the Zip library is not enabled by default and must be downloaded from the
links above. Use the --with-zip=DIR configure option to include Zip support.
Installation on Windows Systems
PHP 5+: Zip functions is not enabled by default, so the php_zip.dll and the ZZIPlib library must be
downloaded from the link above. php_zip.dll must be enabled inside of php.ini.
To enable any PHP extension, the PHP extension_dir setting (in the php.ini file) should be set to the
directory where the PHP extensions are located. An example extension_dir value is c:phpext.

PHP Zip File Functions
Function

Description

PHP

zip_close()

Closes a ZIP file

4

zip_entry_close()

Closes an entry in the ZIP file

4

zip_entry_compressedsize()

Returns the compressed size of an entry in the ZIP file

4

zip_entry_compressionmethod()

Returns the compression method of an entry in the ZIP 4
file

zip_entry_filesize()

Returns the actual file size of an entry in the ZIP file

4

zip_entry_name()

Returns the name of an entry in the ZIP file

4

zip_entry_open()

Opens an entry in the ZIP file for reading

4

zip_entry_read()

Reads from an open entry in the ZIP file

4

zip_open()

Opens a ZIP file

4

zip_read()

Reads the next entry in a ZIP file

4

******************END*******************

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