OpenGurukul : Language : PHP

PHP By OpenGurukul Teamwww.opengurukul.com

Chapter 1Introduction to php www.opengurukul.com 2

Introduction to web applicationWhat is Web Application?Components of Web Application-Presentation-ProcessingUses of PhP- Server Side Scripting- Command Line Scripting www.opengurukul.com 3- Writing Desktop Applications

Introduction to PHPBasic PHP Syntax<?php ?>Example of php program<html><body><?php echo “Hello world”; ?></body></html>Comments in php<html><body><?php //This is a comment/*This is a comment block */?> www.opengurukul.com 4</body></html>

Chapter 2Php data types www.opengurukul.com 5

Php data TypesA data type refers to the type of data a variable can store.8 different type of data types are:integer numbersfloating point numbersstringsbooleansarraysobjectsresouces www.opengurukul.com 6null

IntegersAn integer is a number of the set Z = {..., -2, -1, 0, 1, 2, ...}.Example<?php$a = 1234; // decimal number$a = -123; // a negative number$a = 0123; // octal number (equivalent to 83 decimal)$a = 0x1A; // hexadecimal number (equivalent to 26 decimal)?>Integer Data type can be divided into two types – Octal, Hexadecimal, Decimal www.opengurukul.com 7

Floating point numbersFloating point numbers are those data types which can store decimal valuesExample<?php$a = 1.234;$b = 1.2e3;$c = 7E-10;?> www.opengurukul.com 8

StringsA string is series of characters.Example<?php$str=”Hello world”;echo $str;?>Output: Hello World www.opengurukul.com 9

BooleansThis variable must be true or falseExample<? php$foo = True;// assign the value TRUE to $foo?> www.opengurukul.com 10

ArraysAn array is a variable that holds a group of values.Referencing array elements is done like this:Example$arrayName[index];assign a value to an array position:$listing[0] = "first item";$listing[1] = "second item";$listing[2] = "third item"; www.opengurukul.com 11

ObjectAn object is a data type that allows echo "This is example of object data for the storage of not only data type."; but also information on how to process that data. }Example: }<?php $bar = new foo;class foo $bar->do_foo();{ ?>function do_foo() Output :This is example of object data type.{ www.opengurukul.com 12

Resources and NullResourcesResources are really integers under the surface. Their main benefit is that theyre garbage collected when no longer in use. When the last reference to a resource value goes away, the extension that created the resource is called to free any memory, close any connection, etc. for that resource:NullThe NULL value represents a variable that has no value<?php$var = NULL;?> www.opengurukul.com 13

Type CastingPHP will automatically convert data types as necessary across the boardExample<?php $mystring = "wombat"; $myinteger = (integer)$mystring?>At first, $mystring contains a string.However, we type cast it to be an integer, so PHP will convert it to an integer, and place the result into $myinteger www.opengurukul.com 14

Type jugglingif we add two integer variables then the result is integer typebut if we add one integer and one float type variable then the result is float type because float type has a higher precedence than integer.Example<?php$foo = "0"; // $foo is string (ASCII 48)$foo += 2; // $foo is now an integer (2)$foo = $foo + 1.3; // $foo is now a float (3.3)$foo = 5 + "10 Little Piggies"; // $foo is integer (15)$foo = 5 + "10 Small Pigs"; // $foo is integer (15) www.opengurukul.com 15?>

Chapter 3Variables www.opengurukul.com 16

variablesVariables are used for storing valuesWhen 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 variable name is case-sensitive.Ex-$var_name = value; www.opengurukul.com 17

PHP-loosely typed languageExample<?php$txt="Hello World!";$x=16;?>a variable does not need to be declared before adding a value to it.It automatically converts the variable to the correct data type, depending on its value. www.opengurukul.com 18

Variable scopeExample<?php$a=1; /* global scope*/function test(){echo $a;} /* reference to local scope variable*/}test();?>output:It will not produce any output www.opengurukul.com 19

Global keywordExample<?php $a=1; $b=2; function sum() { global $a, $b; $b = $a + $b; } Sum(); echo $b; www.opengurukul.com 20 ?> output: 3

Variables variablesExample<?php$a=”hello”;$$a=”world”;echo "$a ${$a}";?>Here $a is hello then $hello is world so final out put is hello world www.opengurukul.com 21

Chapter 4Constants And Expressions www.opengurukul.com 22

ConstantsConstants just as variables are used to store information.difference between constants and variables is that constant value can not be changed in the process of running program.A constant is case-sensitive by defaultdefine a constant by using the define()-function or the const keyword outside a class definition. www.opengurukul.com 23

Define functionExample<?phpdefine("PASSWORD","admin"); // first we define a constant PASSWORDecho (PASSWORD); // will display value of PASSWORD constant, i.e. adminecho constant("PASSWORD"); // will also display adminecho "PASSWORD"; // will display PASSWORD?> www.opengurukul.com 24

Const keywordExample<?phpconst CONSTANT = Hello World; // Works as of PHP 5.3.0echo CONSTANT;?> www.opengurukul.com 25

Magic ConstantsPHP provides a large number of predefined constants to any script which it runs.__LINE__:The current line number of the file__FILE__:The full path and filename of the file__DIR__:The directory of the file__FUNCTION__:The function name(case-sensitive)__CLASS__:The class name(case-sensitive)__METHOD__:The class method name(case-sensitive)__NAMESPACE__:The name of the current namespace (case-sensitive) www.opengurukul.com 26

ExpressionsExample$a = “5"youre assigning 5 into $a. 5, obviously, has the value 5, or in other words 5 is an expression with the value of 5 (in this case, 5 is an integer constant).After this assignment, youd expect $as value to be 5 as well.So if you wrote $b = $a, youd expect it to behave just as if you wrote $b = 5. In other words.$a is an expression with the value of 5 as well. www.opengurukul.com 27

Chapter 5Operators www.opengurukul.com 28

OperatorsOperators are used to operate on values.Different types of operators we are using in php.i.Arithmetic Operatorsii.Assignment Operatorsiii.Comparison Operatorsiv.Logical Operators www.opengurukul.com 29

Arithmetic OperatorsOperator Description Example Result+ Addition x=2,x+2 4- Subtraction x=2,5-x 3* Multiplication x=4 20 x*5/ Division 15/5 3 5/2 2.5% Modulus (division 5%2 1 remainder) 10%8 2 10%2 0++ Increment x=5 x=6 x++-- Decrement x=5 x=4 x-- www.opengurukul.com 30

Assignment OperatorsOperator 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 www.opengurukul.com 31

Comparision OperatorsOperator 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 5>=8 returns equal to false<= is less than or 5<=8 returns true equal to www.opengurukul.com 32

Logical OperatorsOperator 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 www.opengurukul.com 33

Operator precedenceExample1 + 5 * 3=16 and not 18because ("*") operator has a higher precedence than the ("+") operatorParentheses may be used to force precedence, if necessary.(1 + 5) * 3=18If operator precedence is equal, left to right associativity is used. www.opengurukul.com 34

Chapter 6Control Structure www.opengurukul.com 35

Conditional StatementsConditional statements are used to perform different actions based on different conditions.PhP have the following conditional statementsif statementif else statementif elseif else statementswitch statement www.opengurukul.com 36

If statementSyntax Exampleif (condition) <?phpcode to be executed if condition is true; $a=2; if($a==2)else echo “It is two”;code to be executed if condition is false; ?> output::It is two www.opengurukul.com 37

If else StatementSyntax Example <?phpif (condition) $a=2;code to be executed if condition is true; $b=3; if($b>$a)else {code to be executed if condition is echo “b is greater”; false; } else { echo “a is greater”; } www.opengurukul.com 38 ?> output::b is greater

The if...else if....else StatementUse the if....elseif...else statement to select one of several blocks of code to be executed.Syntaxif (condition) code to be executed if condition is true;elseif (condition) code to be executed if condition is true;else code to be executed if condition is false; www.opengurukul.com 39

if..else if..else statementExample elseif ($a == $b)<?php {$a=3; echo "a is equal to b";$b=4; }if ($a > $b) else{ {echo "a is bigger than b"; echo "a is smaller than b";} } ?> output: a is smaller than b www.opengurukul.com 40

Switch statementUse the switch statement to select one of many blocks of code to be executed.Syntaxswitch (n){case label1:code to be executed if n=label1;break;case label2:code to be executed if n=label2;break;default: www.opengurukul.com 41code to be executed if n is different from both label1 and label2;}

Switch statementExample case 3:<?php echo "Number 3";$x=1; break;switch ($x) default:{ echo "No number between 1 and 3";case 1: }echo "Number 1"; ?>break; output:Number 1case 2:echo "Number 2";break; www.opengurukul.com 42

loopingA loop is simply a block of code that executes multiple times.The following loops are available in php- while statement- do while statement- for statement- foreach statement www.opengurukul.com 43

The while loopThis loop executes a block of code Example while a condition is true. <?phpSyntax $i=1;while (condition) while($i<=5){ {code to be executed; echo $i;} $i++; } ?> output:12345 www.opengurukul.com 44

The do...while StatementThe loop will always execute the block of Example code once,then check the condition, and repeat the loop while the <?php condition is true. $i=1;Syntax dodo {{code to be executed; $i++;} echo $i;while (condition); } while ($i<=5); ?> www.opengurukul.com 45 output:123456

The for statementThe loop is used when you know in Example advance how many times the <?php script should run. for ($i=1; $i<=5; $i++)Syntax {for (init; condition; increment) echo $i ;{code to be executed; }} ?> output:12345 www.opengurukul.com 46

The foreach LoopThe foreach loop is used to loop through arrays.Syntaxforeach ($array as $value){code to be executed;}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, youll be looking at the next array value. www.opengurukul.com 47

Chapter 7 Array www.opengurukul.com 48

ArrayArray is a special type of variable which stores similar types of data.There are 3 types of arrayNumeric array:An array with a numeric indexAssociative array:An array where each ID key is associated with a valueMultidimensional array:An array containing one or more arrays www.opengurukul.com 49

Numeric ArraysThere are two methods to create a numeric array.i.In the following example the index are automatically assigned (the index starts at 0):Ex-$cars=array("Saab","Volvo","BMW","Toyota");ii.In the following example we assign the index manually:$cars[0]="Saab";$cars[1]="Volvo";$cars[2]="BMW";$cars[3]="Toyota"; www.opengurukul.com 50

Associative ArraysExample1In this example we use an array to assign ages to the different persons$ages = array("Peter"=>32, "Quagmire"=>30, "Joe"=>34);Example2$ages[Peter] = "32";$ages[Quagmire] = "30";$ages[Joe] = "34"; www.opengurukul.com 51

Multidimensional ArraysExample<?php$families = array("Griffin"=>array ("Peter","Lois","Megan" ),"Quagmire"=>array("Glenn" ),"Brown"=>array ("Cleveland", "Loretta", "Junior" ));?>OutputArray([Griffin] => Array([0] => Peter [1] => Lois [2] => Megan)[Quagmire] => Array([0] => Glenn )[Brown] => Array([0] => Cleveland [1] => Loretta [2] => Junior )) www.opengurukul.com 52

Array FunctionsList()The list() function is used to assign values to a list of variables in one operation.Syntaxlist(var1,var2...)Example<?php $my_array = array("Dog","Cat","Horse");list($a, $b, $c) = $my_array;echo "I have several animals, a $a, a $b and a $c.";?>output:I have several animals, a Dog, a Cat and a Horse. www.opengurukul.com 53

count()The count() function counts the elements of an array, or the properties of an object.Syntaxcount(array,mode)Example<?php $people = array("Peter", "Joe", "Glenn", "Cleveland");$result = count($people);echo $result;?>output: 4 www.opengurukul.com 54

array_sum()The array_sum() function returns the sum of all the values in the array.Syntaxarray_sum(array)Example<?php$a=array(0=>"5",1=>"15",2=>"25");echo array_sum($a);?>output: 45 www.opengurukul.com 55

Many other functions are therearray_pop() - Pop the element off the end of arrayarray_push - Push one or more elements onto the end of arraysort - Sort an arrayasort - Sort an array and maintain index associationarsort - Sort an array in reverse order and maintain index associationksort - Sort an array by keykrsort - Sort an array by key in reverse orderprint_r - Display all the readable information about the array www.opengurukul.com 56

Chapter 8PHP Forms and User Inputs www.opengurukul.com 57

Html form exampleExampleThe example below contains an HTML form with two input fields and a submit button: html_form.php<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> www.opengurukul.com 58</html>

Collecting data from a formWhen 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:File: welcome.php<html><body>Welcome <?php echo $_POST["fname"]; ?>!<br />You are <?php echo $_POST["age"]; ?> years old.</body></html>ouput: Welcome John! You are 28 years old. www.opengurukul.com 59

Php $_GET functionIt is used to collect values from a form.Information sent from a form is visible to everyone (it will be displayed in the browsers address bar)Not fit for sending passwords or other sensitive information!Not suitable for very large variable values.(not exceeding 2000 characters) www.opengurukul.com 60

$_GET functionExample<form action="welcome.php" method="get">Name: <input type="text" name="fname" />Age: <input type="text" name="age" /><input type="submit" /></form>URL looks like this:http://www.w3schools.com/welcome.php?fname=Peter&age=37In welcome.phpWelcome <?php echo $_GET["fname"]; ?>.<br />You are <?php echo $_GET["age"]; ?> years old! www.opengurukul.com 61

Php $_POST functionIt is also used to collect values from a form.Information sent from a form is invisible to others and has no limits on the amount of information to send.here is an 8 Mb max size for the POST method, by default .Size can be changed by setting the post_max_size in the php.ini file.It is fit for the password or any other sensitive information www.opengurukul.com 62

$_POST functionExample<form action="welcome.php" method="post">Name: <input type="text" name="fname" />Age: <input type="text" name="age" /><input type="submit" /></form>The URL will look like this:http://www.w3schools.com/welcome.phpIn welcome.phpWelcome <?php echo $_POST["fname"]; ?>!<br /> www.opengurukul.comYou are <?php echo $_POST["age"]; ?> years old. 63

Php $_REQUEST functionThis function contains the contents of both $_GET, $_POST, and $_COOKIE.It can be used to collect form data sent with both the GET and POST methods.ExampleWelcome <?php echo $_REQUEST["fname"]; ?>!<br />You are <?php echo $_REQUEST["age"]; ?> years old. www.opengurukul.com 64

Chapter 9String Handling www.opengurukul.com 65

String VariablesA string variable is used to store and manipulate text.Example<?php$txt="Hello World";echo $txt;?>output: Hello World www.opengurukul.com 66

String Literal SyntaxA string literal can be specified in four different ways:single quoteddouble quotedheredoc syntaxExample of single quoted: <?php $str=Hello World; ?> www.opengurukul.com 67

Example of double quote<?php $str=”hello world”; ?>Example of heredocHeredoc is a robust way to create string in PHP with more lines but without using quotations.<?php$str = <<<DEMOThis is a demo message with heredoc.DEMO;echo $str; ?>output: This is a demo message with heredoc. www.opengurukul.com 68

The concatenation operatorThe concatenation operator (.) is used to put two string values together.Example<?php$txt1="Hello World!";$txt2="What a nice day!";echo $txt1 . " " . $txt2;?>output: Hello World! What a nice day! www.opengurukul.com 69

String FunctionStrlen()The strlen() function is used to return the length of a string.Syntaxint strlen ( string $string )Example<?php$str = abcdef;echo strlen($str); // 6$str = ab cd ;echo strlen($str); // 7 www.opengurukul.com 70?>

str_replace()It replaces some characters with some other characters in a string.Syntaxstr_replace(find,replace,string,count)Example<?php$arr = array("blue","red","green","yellow");print_r(str_replace("red","pink",$arr,$i));echo "Replacements: $i";?>output:Array([0] => blue [1] => pink [2] => green [3] => yellow) Replacements: 1 www.opengurukul.com 71

strrev()The strrev() function reverses a string.Syntaxstrrev(string)Example<?phpecho strrev("Hello World!");?>output : !dlroW olleH www.opengurukul.com 72

Strrpos()The strrpos() function finds the position of the last occurrence of a string inside another string.Syntaxstrrpos(string,find,start)Example<?phpecho strrpos("Hello world!","wo");?>output: 6 www.opengurukul.com 73

Explode()The explode() function breaks a string into an array.Syntaxexplode(separator,string,limit)Example<?php$str = "Hello world. Its a beautiful day.";print_r (explode(" ",$str));?>output:Array([0] => Hello [1] => world. [2] => Its [3] => a [4] => beautiful [5] => day.) www.opengurukul.com 74

Chapter 10Function www.opengurukul.com 75

FunctionA function is a block of code that performs a specific task. It has a name and it is reusable.There are two types of functions-Built-in functions-User defined functions www.opengurukul.com 76

User defined functionFunctions those are defined by user Example according to user requirements. <?phpSyntax function writeName()function functionName() {{ echo "Kai Jim Refsnes";code to be executed; }} echo "My name is "; writeName(); ?> output: My name is Kai Jim Refsnes www.opengurukul.com 77

Function ArgumentsInformation may be passed to echo "My sisters name is "; functions via the argument list, writeName("Hege"); which is a comma-delimited list of expressions. ?> output:My name is Kai Jim Refsnes.Example My sisters name is Hege Refsnes.<?phpfunction writeName($fname){echo $fname . " Refsnes.<br />";}echo "My name is ";writeName("Kai Jim"); www.opengurukul.com 78

Pass by value vs. Pass by referenceEx-pass by value Ex-pass by reference<?php <?phpfunction pass_by_value($param) function_by_reference(&$param){ {push_array($param, 4, 5); push_array($param, 4, 5);} }$ar = array(1,2,3); $ar = array(1,2,3);pass_by_value($ar); pass_by_reference($ar);foreach ($ar as $elem) foreach ($ar as $elem){ {print "<br>$elem"; print "<br>$elem";} } www.opengurukul.com 79?> output:1, 2, 3 ?> output: 1, 2, 3, 4, 5.

Return valuesTo let a function return a value, use the return statement .Example<?phpfunction add($x,$y){$total=$x+$y;return $total;}echo "1 + 16 = " . add(1,16);?>ouput:1 + 16 = 17 www.opengurukul.com 80

Built-in functionDate()The PHP date() function is used to format a time and/or date.Syntaxdate(format,timestamp)Example<?php echo date("Y/m/d") . "<br />";echo date("Y.m.d") . "<br />";echo date("Y-m-d"); ?>output:2009/05/11 2009.05.11 2009-05-11 www.opengurukul.com 81

mktime()The mktime() function returns the Unix timestamp for a date.Syntaxmktime(hour,minute,second,month,day,year,is_dst)Example<?php$tomorrow = mktime(0,0,0,date("m"),date("d")+1,date("Y"));echo "Tomorrow is ".date("Y/m/d", $tomorrow);?>output:Tomorrow is 2009/05/12 www.opengurukul.com 82

include()You can insert the content of one PHP file into another PHP file before the server executes itExample<html><body><?php include("header.php"); ?><h1>Welcome to my home page!</h1><p>Some text.</p></body></html> www.opengurukul.com 83

Require()It is identical as the include functionExample()<?phprequire("wrongFile.php");echo "Hello World!";?> www.opengurukul.com 84

Include vs RequireInclude RequireGenerates warning if file not found Gives fatal error if file not foundScript will continue execution Script will stop www.opengurukul.com 85

require_once() & include_once()include_once() and require_once() function is used to include a file only once in a page.Example<?phprequire_once(“header.php");include_once(“header.php");?> www.opengurukul.com 86

Chapter 11cookies www.opengurukul.com 87

cookieA cookie is often used to identify a user.A cookie is a small file that the server embeds on the users computer.It is used for an origin website to send state information to a users browser and for the browser to return the state information to the origin site www.opengurukul.com 88

Creating CookieThe setcookie() function is used to set a cookie.Syntaxsetcookie(name, value, expire, path, domain);Example<?phpsetcookie("user", "Alex Porter", time()+3600);?> www.opengurukul.com 89

Retrieving Cookie ValueThe PHP $_COOKIE variable is used to retrieve a cookie value.Example<?phpecho $_COOKIE["user"]; // Print a cookieprint_r($_COOKIE); // A way to view all cookies?> www.opengurukul.com 90

Deliting cookieWhen deleting a cookie you should assure that the expiration date is in the past.Example<?php// set the expiration date to one hour agosetcookie("user", "", time()-3600);?> www.opengurukul.com 91

Chapter 12Sessions www.opengurukul.com 92

SessionsA 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. www.opengurukul.com 93

Starting a PHP SessionBefore you can store user information in your PHP session, you must first start up the session.Session_start() is used to start a sessionExample<?php session_start(); ?><html><body></body></html> www.opengurukul.com 94

Storing a Session VariableExample<?phpsession_start();$_SESSION[user]=”Ram”;echo $_SESSION[user];?>output:Ram www.opengurukul.com 95

Destroying a SessionUnset() and session_destroy() are used to delete the sessionunset():It is used to free the specified session variable:Example of unset()<?phpunset($_SESSION[views]);?>session_destroy():is used to compltetly destroy the sessionExample of session_destroy()<?phpsession_destroy(); www.opengurukul.com 96?>

Chapter 13File Handling www.opengurukul.com 97

File open Fopen() is used to open a filefirst parameter shows file name and the second parameter shows mode of the fileExample<?php$file=fopen("welcome.txt","r");?> www.opengurukul.com 98

Closing a FileThe fclose() function is used to close an open file:Example<?php$file = fopen("test.txt","r");//some code to be executedfclose($file);?> www.opengurukul.com 99

Check End-of-fileThe feof() function checks if the "end-of-file" (EOF) has been reached.Example<?phpif (feof($file))echo "End of file";?> www.opengurukul.com 100

File Reading - Line by LineThe fgets() function is used to read a single line from a file.Example<?php$file = fopen("welcome.txt", "r") or exit("Unable to open file!");//Output a line of the file until the end is reachedwhile(!feof($file)){echo fgets($file). "<br />";}fclose($file);?> www.opengurukul.com 101

File Reading - Character by CharacterThe fgetc() function is used to read a single character from a file.Example<?php$file=fopen("welcome.txt","r") or exit("Unable to open file!");while (!feof($file)){echo fgetc($file);}fclose($file);?> www.opengurukul.com 102

File uploadCreate an Upload-File Form<html><body><form action="upload_file.php" method="post" enctype="multipart/form-data"><label for="file">Filename:</label><input type="file" name="file" id="file" /><input type="submit" name="submit" value="Submit" /></form></body></html> www.opengurukul.com 103

Create The Upload ScriptExample else<?php {if ($_FILES["file"]["error"] > 0) echo "Upload: " . $_FILES["file"]["name"] . "<br />";{ echo "Type: " . $_FILES["file"]["type"] .echo "Error: " . $_FILES["file"]["error"] . "<br />"; "<br />"; echo "Size: " . ($_FILES["file"]["size"] /} 1024) . " Kb<br />"; echo "Stored in: " . $_FILES["file"] ["tmp_name"]; } ?> www.opengurukul.com 104

Restrictions on UploadExample echo "Upload: " . $_FILES["file"]["name"] . "<br />";<?php echo "Type: " . $_FILES["file"]["type"] . "<brif ((($_FILES["file"]["type"] == "image/gif") || />"; ($_FILES["file"]["type"] == "image/jpeg") || ($_FILES["file"]["type"] == "image/pjpeg")) echo "Size: " . ($_FILES["file"]["size"] / && ($_FILES["file"]["size"] < 20000)) 1024) . " Kb<br />";{ echo "Stored in: " . $_FILES["file"] ["tmp_name"];if ($_FILES["file"]["error"] > 0) }{ }elseecho "Error: " . $_FILES["file"]["error"] . "<br />"; {}else echo "Invalid file";{ } www.opengurukul.com 105 ?>

Chapter 14Sending Email www.opengurukul.com 106

Sending Email using mail()The PHP mail() function is used to Example send emails from inside a script. <?phpSyntax $to = "someone@example.com";mail(to,subject,message,headers,pa $subject = "Test mail"; rameters) $message = "Hello! This is a simple email message."; $from = "someonelse@example.com"; $headers = "From: $from"; mail($to,$subject,$message,$headers); echo "Mail Sent."; ?> www.opengurukul.com 107

Chapter 15Error Handling www.opengurukul.com 108

Default & Other MethodsThe 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.different error handling methods:-Simple "die()" statements-Custom errors and error triggers-reporting www.opengurukul.com 109

Basic Error Handling: Using the die() functionExample<?php if(!file_exists("welcome.txt")){die("File not found");}Else{$file=fopen("welcome.txt","r");}?>Now if the file does not exist you get an error like this: File not found www.opengurukul.com 110

Creating a Custom Error HandlerThis function must be able to handle a minimum of two parametersi.e (error level and error message) but can accept up to five parameters(optionally: file, line-number, and the error context):Syntaxerror_function(error_level,error_message,error_file,error_line,error_context) www.opengurukul.com 111

Error Report levelsE_WARNING: Non-fatal run-time errorsE_NOTICE: Run-time noticesE_USER_ERROR: Fatal user-generated errorE_USER_WARNING: Non-fatal user-generated warningE_USER_NOTICE: User-generated noticeE_RECOVERABLE_ERROR: Catchable fatal errorE_ALL: All errors and warnings, except level E_STRICT www.opengurukul.com 112

Set Error HandlerSyntaxset_error_handler("customError");Example<?php function customError($errno, $errstr) //error handler function{echo "<b>Error:</b> [$errno] $errstr";}set_error_handler("customError"); //set error handlerecho($test); //trigger error?>output: [8] Undefined variable: test www.opengurukul.com 113

Trigger an ErrorIn a script where users can input data it is useful to trigger errors when an illegal input occurs.trigger_error() function is used for this.Example<?php$test=2;if ($test>1){trigger_error("Value must be 1 or below");}?>output: Notice: Value must be 1 or below www.opengurukul.com 114 in C:webfoldertest.php on line 6

Chapter 16Exception Handling www.opengurukul.com 115

Exception HandlingExceptions are used to change the normal flow of a script if a specified error occursWe 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 www.opengurukul.com 116

Basic Use of ExceptionsWhen 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. www.opengurukul.com 117

Basic use of exception output:Fatal error: Uncaught exceptionExample Exception<?php with message Value must be 1 or below in C:webfoldertest.php:6function checkNum($number) Stack trace: #0{ C:webfoldertest.php(12):if($number>1) checkNum(28) #1 {main} thrown in C: webfoldertest.php on line 6{throw new Exception("Value must be 1 or below");}return true;} www.opengurukul.com 118checkNum(2); ?>

Try, throw and catchTry - 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"Throw - This is how you trigger an exception. Each "throw" must have at least one "catch"Catch - This block retrieves an exception and creates an object containing the exception information www.opengurukul.com 119

Try throw catchExample Try<?php {function checkNum($number) checkNum(2);{ echo If you see this, the number is 1 or below;if($number>1) }{ catch(Exception $e)throw new Exception("Value must be 1 or below"); {} echo Message: .$e->getMessage();return true; }} ?> www.opengurukul.com Message: Value must be 1 or below output: 120

Chapter 17 Filter www.opengurukul.com 121

FiltersPHP filters are used to validate and filter data coming from insecure sources, like user input.To test, validate and filter user input or custom data is an important part of any web application. www.opengurukul.com 122

Use of filterWe should always filter all external data!What is external data?-Input data from a form-Cookies-Web services data-Server variables-Database query results www.opengurukul.com 123

Functions and FiltersTo filter a variable, use one of the following filter functions:filter_var() - Filters a single variable with a specified filterfilter_var_array() - Filter several variables with the same or different filtersfilter_input - Get one input variable and filter itfilter_input_array - Get several input variables and filter them with the same or different filters www.opengurukul.com 124

filter_var()Example of filters:we validate an integer using the filter_var() function:$int = 123;if(!filter_var($int, FILTER_VALIDATE_INT)){echo("Integer is not valid");}else{echo("Integer is valid");}?> www.opengurukul.com 125

Validating and SanitizingAre used to validate user input Are used to allow or disallow specified characters in a stringStrict format rules (like URL or E- Mail validating) No data format rulesReturns the expected type on success or FALSE on failure Always return the string www.opengurukul.com 126

Validate inputExample else<?php {if(!filter_has_var(INPUT_GET, "email")) echo "E-Mail is valid";{ }echo("Input type does not exist"); }} ?>else The example tells{ 1. Check if an "email" input variable of the "GET" type existif (!filter_input(INPUT_GET, "email", FILTER_VALIDATE_EMAIL)) 2. If the input variable exists, check if it is a valid e-mail address{echo "E-Mail is not valid"; www.opengurukul.com 127}

Sanitize InputExample The example tells<?php 1. Check if the "url" input of the "POST" type existsif(!filter_has_var(INPUT_POST, "url")) 2. If the input variable exists, sanitize (take{ away invalid characters) and store it in the $url variableecho("Input type does not exist");}else{$url = filter_input(INPUT_POST, "url", FILTER_SANITIZE_URL);}?> www.opengurukul.com 128

Chapter 18PHP & MySQL www.opengurukul.com 129

Connecting to a DatabaseIn PHP,mysql_connect() function is used to connect the databaseSyntaxmysql_connect( servername, username ,password);Example<?php$con = mysql_connect("localhost","root","root”);if (!$con){die(Could not connect: . mysql_error());} www.opengurukul.com 130?>

Closing a ConnectionThe connection will be closed automatically when the script ends.To close the connection before, use the mysql_close() function:Example<?php$con = mysql_connect("localhost","root","root”);if (!$con){die(Could not connect: . mysql_error());}mysql_close($con); www.opengurukul.com 131?>

Creating DatabaseThe CREATE DATABASE statement is used to create a database in MySQL.SyntaxCREATE DATABASE database_nameTo execute the statement query we must use the mysql_query() function www.opengurukul.com 132

Creating databaseExample if (mysql_query("CREATE DATABASE my_db",$con))<?php {$con = mysql_connect("localhost","root","root echo "Database created"; ”); }if (!$con) else{ {die(Could not connect: . mysql_error()); echo "Error creating database: " .} mysql_error(); } mysql_close($con); www.opengurukul.com 133 ?>

Creating TableThe CREATE TABLE statement is used to create a table in MySQL.SyntaxCREATE TABLE table_name(column_name1 data_type,column_name2 data_type,column_name3 data_type,) www.opengurukul.com 134

Creating tableExample else<?php {$con = echo "Error creating database: " . mysql_connect("localhost","root","root”); mysql_error();if (!$con) }{ mysql_select_db("my_db", $con);die(Could not connect: . mysql_error()); $sql = "CREATE TABLE Persons} (if (mysql_query("CREATE DATABASE FirstName varchar(15), my_db",$con)) LastName varchar(15),{ )";echo "Database created"; mysql_query($sql,$con); www.opengurukul.com 135} mysql_close($con); ?>

Inserting data to DBThe INSERT INTO statement is used to add new records to a database table.SyntaxINSERT INTO table_nameVALUES (value1, value2, value3,...)INSERT INTO table_name (column1, column2, column3,...)VALUES (value1, value2, value3,...) www.opengurukul.com 136

Insert Data From a Form Into a DatabaseHere is the HTML form:form.php<html><body><form action="insert.php" method="post">Firstname: <input type="text" name="firstname" />Lastname: <input type="text" name="lastname" /><input type="submit" /></form></body></html> www.opengurukul.com 137

continueIn insert.php $sql="INSERT INTO Persons (FirstName, LastName, Age)<?php VALUES$con = mysql_connect("localhost","root","root”); ($_POST[firstname],$_POST[lastname],$_ POST[age])";if (!$con) if (!mysql_query($sql,$con)){ {die(Could not connect: . mysql_error()); die(Error: . mysql_error());} }mysql_select_db("my_db", $con); echo "1 record added"; mysql_close($con) ?> www.opengurukul.com 138

Select statementIt is used to select data from a mysql_select_db("my_db", $con); database. $result = mysql_query("SELECT * FROM Persons");Syntax while($row = mysql_fetch_array($result))SELECT column_name(s) FROM table_name { echo $row[FirstName] . " " .Example $row[LastName];<?php echo "<br />";$con = } mysql_connect("localhost","root","root”); mysql_close($con);if (!$con) ?>{die(Could not connect: . mysql_error()); www.opengurukul.com 139}

Update statementIt is used to update existing records if (!$con) in a table. {Syntax die(Could not connect: . mysql_error());UPDATE table_name SET } column1=value, mysql_select_db("my_db", $con); column2=value2,... mysql_query("UPDATE Persons SET Age =WHERE some_column=some_value 36 WHERE FirstName = Peter AND LastNameExample = Griffin");<?php mysql_close($con);$con = ?> mysql_connect("localhost","root","root”); www.opengurukul.com 140

Delete statementThe DELETE FROM statement is if (!$con) used to delete records from a { database table. die(Could not connect: . mysql_error());Syntax }DELETE FROM table_name mysql_select_db("my_db", $con); WHERE some_column = some_value mysql_query("DELETE FROM Persons WHERE LastName=Griffin");Example mysql_close($con);<?php ?>$con = mysql_connect("localhost","root","root”); www.opengurukul.com 141

Important functionsmysql_num_rows:Get number of rows in resultmysql_affected_rows:Get number of affected rows in previous MySQL operationmysql_select_db:Select a MySQL database www.opengurukul.com 142

mysql_num_rowsExample<?php$link = mysql_connect("localhost", "mysql_user", "mysql_password");mysql_select_db("database", $link);$result = mysql_query("SELECT * FROM table1", $link);$num_rows = mysql_num_rows($result);echo "$num_rows Rowsn";?> www.opengurukul.com 143

mysql_affected_rowsExample<?php$link = mysql_connect(localhost, mysql_user, mysql_password);if (!$link) {die(Could not connect: . mysql_error());}mysql_select_db(mydb);mysql_query(DELETE FROM mytable WHERE id < 10);printf("Records deleted: %dn", mysql_affected_rows());mysql_query(DELETE FROM mytable WHERE 0);printf("Records deleted: %dn", mysql_affected_rows()); www.opengurukul.com 144?>

mysql_select_dbExample<?php$link = mysql_connect(localhost, mysql_user, mysql_password);if (!$link) {die(Not connected : . mysql_error());}$db_selected = mysql_select_db(foo, $link);if (!$db_selected) {die (Cant use foo : . mysql_error());}?> www.opengurukul.com 145

Chapter 19PHP & ODBC www.opengurukul.com 146

Create an ODBC ConnectionHere is how to create an ODBC connection to a MS Access Database:1.Open the Administrative Tools icon in your Control Panel.2.Double-click on the Data Sources (ODBC) icon inside.3. Choose the System DSN tab.4.Click on Add in the System DSN tab.5. Select the Microsoft Access Driver. Click Finish.6. In the next screen, click Select to locate the database.7.Give the database a Data Source Name (DSN).8. Click OK. www.opengurukul.com 147

DSN On Linux:To use MySQL via ODBC:<?php$db_host = "server.mynetwork";$db_user = "dbuser";$db_pass = "dbpass";$dsn = "DRIVER={MySQL ODBC 3.51 Driver};" ."CommLinks=tcpip(Host=$db_host);" ."DatabaseName=$db_name;" ."uid=$db_user; pwd=$db_pass";odbc_connect($dsn, $db_user, $db_pass); www.opengurukul.com 148?>

Connecting to an ODBCThe odbc_connect() is used to connect to an ODBC data source.It takes four parameters:-data source name-username-password-optional cursor type.ExampleThe following example creates a connection to a DSN called northwind, with no username and no password.$conn=odbc_connect(northwind,,); www.opengurukul.com 149

Executing SQL Statement: odbc_exec()The odbc_exec() function is used to execute an SQL statement.Exampleexample 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); www.opengurukul.com 150

Retrieving Records odbc_fetch_row()This function is used to return records from the result-set.The function takes two parameters:- ODBC result identifier- an optional row numberExampleodbc_fetch_row($rs) www.opengurukul.com 151

Retrieving Fields from a Record: odbc_result()This function is used to read fields from a record.It takes two parameters:-The ODBC result identifier- a field number or name.Example1$compname=odbc_result($rs,1);returns the value of the first field from the record:Example2$compname=odbc_result($rs,"CompanyName");returns the value of a field called "CompanyName": www.opengurukul.com 152

Closing an ODBC Connection: odbc_close()The odbc_close() function is used to close an ODBC connection.Exampleodbc_close($conn); www.opengurukul.com 153

Chapter 20Object Oriented Programming www.opengurukul.com 154

classesA class is user defined data type that contains attributes or data members; and methods which work on the data members.Class structureclass <class-name>{<class body :- Data Members & Methods>;} www.opengurukul.com 155

Class exampleclass Customer //customer is the class name{private $first_name, $last_name; //$first_name/$last_name are attributes or data members.public function setData($first_name, $last_name) //setData is the method{$this->first_name = $first_name;$this->last_name = $last_name;}public function printData() //printData is also the method{echo $this->first_name . " : " . $this->last_name;} www.opengurukul.com 156}

The new instanceTo create an instance of a class, the new keyword must be used.An object will always be created when unless the object has a constructor defined that throws an exception on error.Classes should be defined before instantiationIf a string containing the name of a class is used with new, a new instance of that class will be created.Syntax$instance = new Class();Or we can write $className = Foo; $instance = new $className(); www.opengurukul.com 157

Object assignmentExample$instance = new SimpleClass();$assigned = $instance;$reference =& $instance;$instance->var = $assigned will have this value;$instance = null; // $instance and $reference become nullvar_dump($instance);var_dump($reference);var_dump($assigned); www.opengurukul.com 158

Extends keywordA class can inherit the methods and } properties of another class by $extended = new ExtendClass(); using the keyword extends in the class declaration. $extended->displayVar(); ?>Example output:Extending class<?php a default valueclass ExtendClass extends SimpleClass{function displayVar(){ echo "Extending classn"; parent::displayVar(); www.opengurukul.com 159}

PropertiesClass member variables are called "properties"They are defined public, protected, or private, followed by a normal variable declaration.This declaration may include an initialization, but this initialization must be a constant value www.opengurukul.com 160

PropertiesExample // valid property declarations:<?php public $var6 = myConstant;class SimpleClass public $var7 = array(true, false);{ // This is allowed only in PHP 5.3.0 and later. // invalid property declarations: public $var8 = <<<EODpublic $var1 = hello . world; hello worldpublic $var2 = <<<EOD EOD;hello world }EOD; ?>public $var3 = 1+2;public $var4 = self::myStaticMethod();public $var5 = $myVar; www.opengurukul.com 161

Class constantsExample<?phpclass MyClass{const constant = Any Testing Constant Value;function showConstant() {echo self::constant . "n";}}echo MyClass::constant . "n";?> www.opengurukul.com 162output: Any Testing Constant Value

ConstructorSyntax class SubClass extends BaseClassvoid __construct ([ mixed $args [, $... ]] ) { function __construct()Example {<?php parent::__construct();class BaseClass print "SubClass constructorn";{ }function __construct() }{ $obj = new BaseClass();print "BaseClass constructorn"; $obj = new SubClass();} ?>} www.opengurukul.com Output: BaseClass constructor BaseClass 163 constructor SubClass constructor.

DestructorSyntax function __destruct() {void __destruct ( void ) print "Destroying " . $this->name . "n";Example }<?php }class MyDestructableClass $obj = new MyDestructableClass();{ ?>function __construct() Output{ In constructor Destroyingprint "In constructorn"; MyDestructableClass$this->name = "MyDestructableClass";} www.opengurukul.com 164

Object inheritanceExample class bar extends foo<?php {class foo public function printItem($string){ {public function printItem($string) echo Bar: . $string . PHP_EOL;{ }echo Foo: . $string . PHP_EOL; }} $foo = new foo(); $bar = new bar();public function printPHP() $foo->printItem(baz); // Output: Foo: baz{ $foo->printPHP(); // Output: PHP is greatecho PHP is great. . PHP_EOL; $bar->printItem(baz); // Output: Bar: baz} $bar->printPHP(); // Output: PHP is great ?> www.opengurukul.com 165} output:Foo: baz PHP is great. Bar: baz PHP is great.

Scope Resolution Operator (::)It is a token that allows access to static, constant, and overridden properties or methods of a class.The variables value can not be a keyword (e.g. self, parent and static).Example<?phpclass MyClass{const CONST_VALUE = Any constant value;}$classname = MyClass;echo MyClass::CONST_VALUE; ?>output:Any constant value www.opengurukul.com 166

Self and parentTwo special keywords self and parent class OtherClass extends MyClass are used to access properties or { methods from inside the class definition. public static $my_static = static var; public static function doubleColon()Example {<?php echo parent::CONST_VALUE . "<br>";class MyClass echo self::$my_static . "<br>";{ }const CONST_VALUE = Any constant value; }} $classname = OtherClass;$classname = MyClass; OtherClass::doubleColon(); ?> www.opengurukul.com 167 Output: A constant value static var

Static keywordDeclaring class properties or methods as static makes them accessible without needing an instantiation of the class.A property declared as static can not be accessed with an instantiated class object .The variables value can not be a keyword (e.g. self, parent and static). www.opengurukul.com 168

Static keywordExample }<? public function getStaticData()class ClassName {{ echo ClassName::$staticvariable; //Accessing Static Variablestatic private $staticvariable; //Defining Static Variable }function __construct($value) }{ $a = new ClassName("12");if($value != "") $a = new ClassName("23");{ $a = new ClassName("");ClassName::$staticvariable = $value; //Accessing ?> Static Variable Output:12} www.opengurukul.com 23 169$this->getStaticData(); 23

Abstract classesIt is not allowed to create an instance of a class that has been defined as abstract.Syntax<?abstract class classname{//attributes and methodsabstract function methodname}class derived extends classname{ function methodname} www.opengurukul.com 170?>

Abstract classExample class EmployeeData extends employee //extending abstract class<? {abstract class employee function __construct($name,$age){ {protected $empname; $this->setdata($name,$age);protected $empage; }function setdata($empname,$empage) function outputData(){ {$this->empname = $empname; echo $this->empname;$this->empage = $empage; echo $this->empage;} }abstract function outputData(); www.opengurukul.com EmployeeData("Hitesh","24"); $a = new 171} $a->outputData(); ?> Output: Hitesh 24

Object interfacesInterface is a object oriented concept,It is the place where we can define the function.SyntaxInterface interface_name{const 1;const N;function methodName1()function methodNameN()} www.opengurukul.com 172

Object interfacesExample function shimu()<?php {interface shahu print "<br />";{ print self::lotu;const lotu="lotu is lucky"; }public function rooja(); }} $hanu=new hasu();class hasu implements shahu $hanu->rooja();{ $hanu ->shimu();public function rooja() ?>print "<br />"; output:lotu is luckyprint self::lotu; print "<br />"; www.opengurukul.comhai roja 173print "hai roja"; } lotu is lucky

OverloadingOverloading in PHP provides means to dynamically "create" properties and methods.All overloading methods must be defined as public.Two types of overloading are there-Property overloading-Method overloading www.opengurukul.com 174

Property overloadingExamplevoid __set ( string $name , mixed $value )mixed __get ( string $name )bool __isset ( string $name )void __unset ( string $name )The $name argument is the name of the property being interacted with.__set() is run when writing data to inaccessible properties.__get() is utilized for reading data from inaccessible properties.__isset() is triggered by calling isset() or empty() on inaccessible properties.__unset() is invoked when unset() is used on inaccessible properties. www.opengurukul.com 175

Method overloadingExamplemixed __call ( string $name , array $arguments )mixed __callStatic ( string $name , array $arguments )-$name argument is the name of the method being called.-The $arguments argument is an enumerated array containing the parameters passed to the $nameed method.__call() is triggered when invoking inaccessible methods in an object context.__callStatic() is triggered when invoking inaccessible methods in a static context. www.opengurukul.com 176

Object iterationPHP 5 provides a way for objects to be foreach($this as $key => $value) defined so it is possible to iterate through { a list of items. print "$key => $value<br>";Example }<?php }class MyClass }{ $class = new MyClass();public $var1 = value 1; foreach($class as $key => $value)public $var2 = value 2; {public $var3 = value 3; print "$key => $value<br>";protected $protected = protected var; }function iterateVisible() echo "<br>";{ www.opengurukul.com 177 $class->iterateVisible(); ?>echo "MyClass::iterateVisible:n";

Magic methodsThere are so many functions which are _wakeup magical in php _toString_construct _invoke_destruct _set_state_call _clone_callStatic_get_set_isset_unset_sleep www.opengurukul.com 178

__sleep and __wakeupSerialize()checks if your class has a function with the magic name __sleep,If so, that function is executed prior to any serializationUnserialize()checks for the presence of a function with the magic name __wakeupIf present, this function can reconstruct any resources that the object may have. www.opengurukul.com 179

__toString,__invoke,__set_state__toStringThe __toString method allows a class to decide how it will react when it is treated like a string.__invokeThe __invoke method is called when a script tries to call an object as a function.__set_stateThis static method is called for classes exported by var_export() since PHP 5.1.0. www.opengurukul.com 180

Final keywordIt prevents child classes from overriding a method by prefixing the definition with final.If the class itself is being defined final then it cannot be extended.Properties cannot be declared final, only classes and methods may be declared as final. www.opengurukul.com 181

Final keywordExample<?phpfinal class BaseClass {public function test() {echo "BaseClass::test() calledn";}final public function moreTesting() // Here it doesnt matter if you specify the function as final or not{echo "BaseClass::moreTesting() calledn";}}class ChildClass extends BaseClass { www.opengurukul.com 182}// Results in Fatal error: Class ChildClass may not inherit from final class (BaseClass) ?>

Cloning objectit simply creates a copy of an object. $so = new SmallObject;Example $so->field++;$x = 1; $soRef = $so;$y =& $x; $soClone = clone $so;$x++; $so->field++;echo"$y $x<br>"; echo $so->field; // outputs: 2class SmallObject echo $soRef->field; // outputs: 2{ echo $soClone->field; // outputs: 1 public $field = 0;} www.opengurukul.com 183

Late static bindingIt can be used to refer the called class.The name late static binding is coined because of the static:: will no longer be resolved using the class where the method is defined. www.opengurukul.com 184

Late static bindingExample class Two extends One { public static function classIdentifier() {<?php echo __CLASS__;class One { }public static function classIdentifier() { }echo __CLASS__; Two::classtest();} ?>public static function classtest() { Output: Oneself::classIdentifier();}} www.opengurukul.com 185

Objects and referencesExample $d->foo = 2; // ($c,$d) = <id><?php echo $c->foo."n";class A { $e = new A; public $foo = 1; function foo($obj) {} // ($obj) = ($e) = <id>$a = new A; $obj->foo = 2;$b = $a; // $a and $b are copies of the same } identifier foo($e); // ($a) = ($b) = <id> echo $e->foo."n";$b->foo = 2; ?>echo $a->foo."n"; output:2$c = new A; 2$d = &$c; // $c and $d are references www.opengurukul.com 186 2

Object serializationSerialization in the context of storage and transmitting is the process of converting an object into a sequence of bitsso that it can persist in a storage medium and or transmitted across a network.serializing and unserializing can be done by two functions They are:-Serialize-unserializeserialize() returns a string containing a byte-stream representation of any valueunserialize() can use this string to recreate the original variable values. www.opengurukul.com 187

Chapter 21PHP Built-in Functions www.opengurukul.com 188

PHP Calendar Functions and constantscal_days_in_month:It Return the number of days in a month for a given year and calendar.Syntax:int cal_days_in_month ( int $calendar , int $month , int $year )Parameters:calendar - Calendar to use for calculation month - Month in the selected calendar year - Year in the selected calendarExample<?php$num = cal_days_in_month(CAL_GREGORIAN, 8, 2003);echo "There was $num days in August 2003";?> www.opengurukul.comOutput -There was 31 days in August 2003 189

cal_infoIt Returns information about a particular calendar.Syntax:array cal_info ([ int $calendar = -1 ] )Parameters:Calendar - Calendar to return information for. If no calendar is specified information about all calendars is returned.Example:<?php $info = cal_info(0); print_r($info); ?>output:Array ( [months] => Array ( [1] => January [2] => February [3] => March [4] => April [5] => May [6] => June [7] => July [8] => August [9] => September [10] => October [11] => November [ www.opengurukul.com 190

Many other calender functioncal_from_jd:It Converts from Julian Day Count to a supported calendar.cal_to_jd:It Converts from a supported calendar to Julian Day Count.FrenchToJD :It Converts a date from the French Republican Calendar to a Julian Day Count.GregorianToJD:It Converts a Gregorian date to Julian Day Count. www.opengurukul.com 191

Date/time Functions and constantsDate functionThe PHP date() function is used to format a time and/or date.Syntaxdate(format,timestamp) ;Parameterformat - Required. Specifies the format of the timestamptimestamp - Optional. Specifies a timestamp. Default is the current date and time. www.opengurukul.com 192

Directory Functions and constantsChdir: It change the directorySyntax: bool chdir ( string $directory )Parameters: directory - The new current directoryExample:<?php // current directory echo getcwd() . "n"; chdir(public_html); // current directory echo getcwd() . "n"; ?>output:/home/vincent www.opengurukul.com 193 /home/vincent/public_html

chrootIt change the root directorySyntaxbool chroot ( string $directory )Parametersdirectory - The path to change the root directory to.Example<?phpchroot("/path/to/your/chroot/");echo getcwd();?>output: / www.opengurukul.com 194

getcwdIt gets the current working directorySyntax: string getcwd ( void )Example:<?php // current directory echo getcwd() . "n"; chdir(cvs); // current directory echo getcwd() . "n"; ?>output:/home/matsya home/matsya/cvs www.opengurukul.com 195

Error Logging functions and constantsdebug_backtrace: It generates a a_test(friend); backtrace. include_once a.txt;Syntax: array debug_backtrace ([ bool ?> $provide_object = true ] ) a.txt:friend is the best part of my lifeParameters output:Hi: friendarray(1) { [0]=> array(4) { ["file"]=> string(13) "/var/test.php" ["line"]=> int(10)provide_object - Whether or not to ["function"]=> string(6) "a_test" ["args"]=> populate the "object" index. array(1) { [0]=> &string(6) "friend" } } } friend is the best part of my lifeExample: <?php function a_test($str) { echo "nHi: $str"; var_dump(debug_backtrace()); } www.opengurukul.com 196

error_logIt send an error message somewhereSyntax: bool error_log ( string $message [, int $message_type = 0 [, string $destination [, string $extra_headers ]]] )Parametersmessage - The error message that should be logged.message_type - Says where the error should go.Destination - The destination. Its meaning depends on the message_type parameter as described above.extra_headers - The extra headers. Its used when the message_type parameter is set to 1.Example:<?php error_log("You messed up!", 3, "/var/tmp/my-errors.log"); ?> www.opengurukul.com 197

File System Functions and constantsBasenameIt returns trailing name component of pathSyntaxstring basename ( string $path [, string $suffix ] )Parameterspath - A path.Suffix - If the name component ends in suffix this will also be cut off.Example<?phpecho "1) ".basename("/etc/sudoers.d", ".d").PHP_EOL;echo "2) ".basename("/etc/passwd").PHP_EOL;?> www.opengurukul.com 198Output 1) sudoers 2) passwd

chmodIt changes file modeSyntax: bool chmod ( string $filename , int $mode )Parametersfilename - Path to the file.Mode - mode is not automatically assumed to be an octal value, so strings (such as "g+w") will not work properly. To ensure the expected operation, you need to prefix mode with a zero (0);Example<?phpchmod("/somedir/somefile", "u+rwx,go+rx"); // string; incorrectchmod("/somedir/somefile", 0755); // octal; correct value of mode?> www.opengurukul.com 199

Math Functions and constantsAbs: It is used to calculate Absolute value.Syntax:number abs ( mixed $number )Parametersnumber - The numeric value to process .Example<?php$abs = abs(-4.2); // $abs = 4.2; (double/float)$abs2 = abs(5); // $abs2 = 5; (integer)$abs3 = abs(-5); // $abs3 = 5; (integer)?>output: 4.2 www.opengurukul.com 200 55

ceilIt is used to find out round fractions up.Syntax: float ceil ( float $value )Parametersvalue - The value to roundMode - mode is not automatically assumed to be an octal value, so strings (such as "g+w") will not work properly. To ensure the expected operation, you need to prefix mode with a zero (0);Example<?phpecho ceil(4.3); // 5echo ceil(9.999); // 10echo ceil(-3.14); // -3?> www.opengurukul.com 201

maxFind highest value.Syntax:mixed max ( array $values )values - An array containing the values.Example :<?phpecho max(1, 3, 5, 6, 7); // 7?> www.opengurukul.com 202

Miscellaneous functionconnection_aborted – Check whether client disconnectedconnection_status - Returns connection status bitfieldconnection_timeout - Check if the script timed outconstant - Returns the value of a constantdefine - Defines a named constantdefined - Checks whether a given named constant existsdie - Equivalent to exiteval - Evaluate a string as PHP codeexit - Output a message and terminate the current script www.opengurukul.com 203

Chapter 22PHP Template Engine - Smarty www.opengurukul.com 204

Smarty IntroductionIt is a template engine that you can use for our websites.It is used to separate your PHP code from your HTML code.When a file is called from the web, the php file is parsed and smarty compiles the results from the template files used.When that same page is called and the template files have not been altered smarty will use the compiled version which causes the server to not need to recompile the pages.Smarty also has the ability to use cache. www.opengurukul.com 205

Smarty FeaturesSmarty is template engine of php.Smarty provides proper responsebility division between presentation and application logics.Smarty is extremely fast.It is very efficient since php parser does the dirty work.No template parsing required and page is compiled once.It is smart about recompiling only the template files that have changed.we can easily create our custom functions and variables.It allows unlimitted sections(loops) and ifs.it provides cache handling.It has a plugin architecture. www.opengurukul.com 206

Chapter 23PHP Framework - CodeIgniter www.opengurukul.com 207

CodeIgniterIt is an Application Development Framework - a toolkit - for people who build web sites using PHP.Its goal is to enable you to develop projects much faster than you could if you were writing code from scratch.CodeIgniter lets you creatively focus on your project by minimizing the amount of code needed for a given task. www.opengurukul.com 208

PHPSUPPORT www.opengurukul.com 209

Support Register yourself on www.opengurukul.comfor any additional support on PHP www.opengurukul.com 210

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