Learn Php Ez Way 2ed

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ISBN 978-0-557-04


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Published By: Lulu.comCopyright Year: 2007Copyright Scriptsez.net. All rights reserved.

The above information forms this copyright notice: 2007 by Scriptsez.net. All rightsreserved.

ISBN 978-0-557-04160-2


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Chapter

GETTING STARTED

WITH HTML

1 Getting Started With HTML

1.1 Basic Q and As:

What is HTML?

HTML (Hyper Text Markup Language) is a computer language devised to

allow website creation.

How does it Work?

HTML consists of a series of short codes (known as tags) typed into a

text-file by the site author. The text file is then saved as .html file, and

viewed through a browser like Internet Explorer. The browser reads the

text and translates it into visible form. You can use anything from notepad

to powerful graphical editor to create web pages.


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What does these tags do?

These tags separate normal text from HTML code. In short, tags are

words between for example, is a tag. These simple tags apply

formatting to the text, look at the code below:

This is bold text and this is not

When the above code is saved as .html file, and opened in your browser

then it will display:

This is bold text and this is not

Tags are not case sensitive, for example use of and will not

make any difference.

Is there anything HTML cant do?

Yes, HTML can only make static pages (it can provide information to the

surfer but can not take information from the visitor). For example, if you

want the visitor to write comments about your web page, then you need to

have a server sided languageto process this request.

1.2 Learning HTMLThis part of the chapter will provide enough information about HTML

language to you to be able to write PHP programs.

An HTML web page consists of two parts, the HEAD part and the BODY

part. HEAD part comes before BODY part.

In the HEAD part, you define how the content in the body part of the web

page will be displayed. HEAD part contains the title of the web page, and

formatting of the text, which will be displayed on the body part of the web

page.

All HTML pages begin with and end with

HEAD part begins with and ends with


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BODY part begins with and ends with

Making a basic Web page:

Adding title of web page:

This is my First Web page

Above code will display a blank web page with the title


Now, lets come to the BODY part. The body part as discussed above

contains the content of the web page.

To display some text in a web page, just add the text in between the body

tag.


My first Web page


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The above code will not only display the title This is my First Web page

but will also display the text My first Web page on the webpage.

1.3 Formatting the text:

Now we will do some formatting to the webpage:

To make the text look bold, add the text in between tags.

For Example:


My first Web page

Similarly, to make the text look italic, use instead of

You can also display the text both bold and italic by using

similarly to underline the text use tag

For Example:


My first Web page

To make the text size larger or smaller, use the tag.

Some text


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The value 4 determines the size of text that will be displayed and the

value of color gives color to text.

To display this text bold and italic, you can use and tags

in between font tag.

For Example:

Some Text

The above code will display the formatted text bold and italic.

To bring the text at center of the web page, use tag.

For Example:

Some text

To change the line:

Use
to change the line, for example you want to display the text

HELLO at the first line and Welcome to my webpage in the next line, then

add
after HELLO

For Example:

HELLO
Welcome to my webpage

1.4 Adding Images:

To add an image, use tag

For example:


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This code will display image logo.gif on your webpage.

To change the height and width of image use:

1.5 Adding Links:

To add links to your webpage, use:

Click Here

Similarly you can add links to images as well by adding image tag inside

link tag.

Example:

To make the link open in new window, use:


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Chapter

PHP Basics

2 PHP BASICSIn this chapter you will be able to get know how of PHP language, how it

works and how you can make php scripts easily!

2.1 Basic Q & As

What is PHP?

PHP, which stands for "Hypertext Preprocessor", is a server-side, HTML

embedded scripting language used to create dynamic Web pages. Much

of its syntax is borrowed from C, Java and Perl with some unique features

thrown in. The goal of the language is to allow Web developers to write

dynamically generated pages quickly.


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How does PHP Work?

In an HTML page, PHP code is enclosed within special PHP tags. When

a visitor opens the page, the server processes the PHP code and then

sends the output (not the PHP code itself) to the visitor's browser. It

means that, unlike JavaScript, you don't have to worry that someone can

steal your PHP script.

What are the advantages of PHP over other Server Sided

Languages?

PHP offers excellent connectivity to many databases including MySQL,

Informix, Oracle, Sybase, Solid, PostgreSQL, and Generic ODBC. The

popular PHP-MySQL combination (both are open-source products) is

available on almost every UNIX host. Being web-oriented, PHP also

contains all the functions to do things on the Internet - connecting to

remote servers, checking email via POP3 or IMAP, url encoding, setting

cookies, redirecting, etc.

What do PHP Code look like?

PHP is a rather simple language. Much of its syntax is borrowed from C

except for dealing with the types of variables. You don't need to think of

the types of variables at all - you just work with their values, not their

types. And you don't have to declare variables before you use them.

Things to remember:


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1. An HTML web page containing PHP code should be save as .php

not as .html

2. A php code starts with

3. Each instruction in PHP code must end with semicolon (;)

2.2 Make your first PHP Web page

Here is a sample:

My first PHP Script

Save the above code in blank file as webpage.php and run this file in your

browser, you will see the following output:

This text is written with PHP

As you might have noticed that the php code starts with

To output we use echo just like in C language.

2.3 Sending Mail with PHP

PHP can be used to send emails, for this purpose, PHP mail() function is

used. Many web servers have this feature enabled.

To send email you must have a subject, a message, recipient and sender.

Let us provide the value of each of the variables:


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The sentence that begins with // are the comments, they can be inserted

in a code but are unreadable by PHP.

2.4 Displaying Date and Time

PHP has many built in functions, mail function used above is one of them.You can use PHP date function to display the time.


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Unlike javascript, the time displayed is the time on servers PC clock.

2.5 Checking File size

You can check the size of any file within the directory or in any

subdirectory.

Lets say we want to get the size of the file, which exists in the same

directory, lets say its name is index.html, then:

The above function filesize() displays the size of file in bytes, you can

convert it into Kilobytes by dividing the output by 1024.

To round off the value to two decimal places just use the round()

function.

In the round function, there are two parameters:


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round (Parameter1,Parameter2);

Parameter 1 is the numeric value that we want to round off and

Parameter 2 is the number of decimal places up to which the number will

be rounded off.

2.6 PHP if and else conditions

PHP has support for conditional sentences. For example, if you would like

to run different output upon different conditions then you can use if and

else condition.

In the following code we will display Pass if the value of a variable is

greater than or equal to 60, and Fail if the output is less than 60.

You can use elseif condition if there are more than two possibilities.

For Example in the code below, we will display Positive when variable is

greater than 60 and Neutral when variable is equal to 60 and Negative

when variable is less than 60, so,


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echo Neutral;

}else{

echo Negative;

}

?>

2.7 Sending data using Forms

In the above examples we have declared the values within the PHP code,

what if user wants to input the value? We use forms to let user input the

data.

A form code is an HTML tag which begins with and ends with

First we create a form, which asks the user a value, and then we output

the user whether it is positive, neutral or negative:

PHP FORM

Please input the value:


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In the above code, within the form code, we have described the type of

input, the first one is TEXT and the other one is SUBMIT type.

The TEXT type displays a text box through which the user inputs the

value, and submit type displays a submit button which upon pressing

submits the input data.

There are several input types, namely:

Hidden: which contains the value in it but is not visible on the page.

Radio: which displays the radio button.

Select: which displays pull down menu with all the available options.

And many more.

2.8 Uploading Files

PHP supports file uploading to server. First we create a form just like we

did before. This form asks the user for the file which the user wants to

upload, an example of code would be:

PHP FILE UPLOAD


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If ($filesize

Select File:

In the above code you can see additional parameter

enctype=multipart/form-data

It is required when file is uploaded.

$HTTP_POST_FILES['picture']['size']) is pre-defined constant in PHP, it provides

filesize in bytes, so it is divided by 1024 to convert it into Kb.

copy($HTTP_POST_FILES['picture']['tmp_name'],$HTTP_POST_FILES['picture'][

'name']);

copy function copies the file from temporary upload directory to your

defined directory. In the above code script will upload the file to the folder

in which you have the script, to upload the file in a sub directory inside

your script directory, use the following code:

copy($HTTP_POST_FILES['picture']['tmp_name'],sub_dir/.$HTTP_POST_FILE

S['picture']['name']);

Above code will upload the file to sub_dir folder (it must already exist).


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2.9 File and directory functions

PHP supports checking the existence of files and directories, to check

whether a file exists in your server or not, use the following code:

Similarly, you can check the directory using:


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2.10 Loop

Loops are very common in any program. Loop is a repetitive task

assigned to script. Two most common types of loop are for and while.

For Loop

Here is a sample of a for loop:

Output of above code will be:

This is 1 line

This is 2 line

This is 3 line

This is 4 lineThis is 5 line

Same text is print five times only the line number changes each time.

For loop consists of three parameters each separated by ; semicolon.

Parameter 1 $i=1 is executed only once.

Parameter 2 $i


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echo This is $i line
;

Since the value of $i is 1, so the script prints:

This is 1 line.

Now, the script goes to the third parameter of for loop, $i++

It means, whatever the value of $i is, add one more to it. So now, the

value of $i is 2. It the goes to parameter number 2, since the value of $i is

still less than five, it again goes inside the loop and prints the line. It

continues until value of $i becomes greater than 5 and the loop ends.

While Loop

While loop is similar to for loop, but it only has one parameter.

Look at the code below:

You can see that initial value of $i is defined outside the loop. Then while

loops checks for the value of $i, if it is less than or equal to 5 then it goes

inside the loop. Inside the loop, the value of $i is increased by 1, so the

loop continues until the value of $i becomes greater than 5.

If you do not increase the value of $i inside the loop, then loop will

continue endlessly, and can cause your system to crash.


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Chapter

Using Database

3 USING DATABASE

3.1 Basic Q & As

What is a Database?

A database is simply a method by which you can store information. Lets

say you want to store information of your employees name and address,

you can use database for this purpose, and stored values can be viewed

using PHP.

What is MySQL?

MySQL is an open source Relational Database Management System that

uses Structured Query Language. Information is stored in "Tables" which


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can be thought of as the equivalent of Excel spreadsheets. A single

MySQL database can contain many tables at once and store thousands

of individual records. It's fast, reliable and flexible.

What is a Flat File Database?

A Flat File database is a simple text file used to store information, and is

most often used when you do not have access to a MySQL database, as

they require no server addons other than PHP. They are best for smaller

amounts of data than a MySQL database is capable of, and have fewer

handling functions, but are very handy for things like counters and guest

books.

3.2 Flat File Databases

Lets start by creating a simple raw visit counter which will count the number of

times a page has been opened.

In the line

$counter_file = file(stats.txt);


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We assign stored value of stats.txt to a variable $counter_file

Then we read the value stored in the file, since the value is on the first

line of the file stats.txt so it is counted as zero line in PHP!

We make a new variable $current_stats and store the value which is on

the first line of stats.txt in it.

New statistics is of course 1 value additional to the old value, e.g. if it was

4 then now it should be 5.

Then we remove everything from the database file using the code:

$file_open=fopen(stats.txt,w);

and write the latest visit statistics

fwrite($file_open,$new_stats);

then we close the database file using:

fclose($file_open);

Then we output the latest visit information using:

echo Number of Visitors: $new_stats;

In the above example the line


opens a text file stats.txt and removes everything from it, if the file does

not exist then it first creates a file stats.txt

NOTE: TO RUN THE ABOVE CODE YOU MUST CREATE A TEXT FILE stats.txt

IN THE SAME DIRECTORY IN WHICH YOU PUT THE FILE WITH THE ABOVE

COUNTER CODE AND SET PERMISSION OF stats.txt TO CHMOD 777

CHMOD refers to setting access privileges to a file. It is required if your web

hosting is on Linux Server. CHMOD 777 means that a file is readable, write able

and executable.

To set the permission-using FTP just right click the file and select CHMOD.

Then select all the check boxes.


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Above code counts raw visits, it means that if a user refreshes this page

100 times it will count it as 100 visits, which is true in case of raw visits

but what if you want to count each user visit as a single hit (which is

called unique visit), for this purpose we will use users IP address to

recognize the user so that one user is counted as 1 hit.

We will require two files one which stores last users IP address (we name

it ip.txt) and other, which stores users statistics (stats.txt).


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Name:

Email:

The code is an HTML code through which name and email fields

are submitted it has been discussed in 3rd chapter.

In the above PHP code if statement has been used, it means that if a

particular condition is meet then the code in between the { and } will beallowed to run.

The line:

$store=fopen(file.txt,a+);

is very much similar to


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used in the previous counter example but in this case a+ has been used

instead of w which means that the file should already exist and

everything written in the file will not be deleted instead it moves the cursor

to the last line of the file.

The code below:

fwrite($store,$name||$email\n);

writes name and email of the user, notice that I have used || in between

$name and $email I will tell you useful purpose of this in the next example

where we will retrieve the information from the text file.

\n in the above code moves the cursor to one line below the line on which

data has been entered (it is just like pressing enter key), so that next time

the data will be entered on a blank new line instead of continuing it from

the same line.

The code:

fclose($store);

as described previously, closes the opened file.

NOTE: TO RUN THE ABOVE CODE YOU MUST CREATE A TEXT FILE file.txt IN

THE SAME DIRECTORY IN WHICH YOU PUT THE FILE WITH THE ABOVE USER

FORM CODE AND SET PERMISSION OF file.txt TO CHMOD 777

Now lets retrieve the data from the text file, which users have submitted.


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The above code displays name and email of all the users.

Here is the description of the code:

On line:

$data_file=file(file.txt);

We store all the information of file.txt in the variable which we have

named $data_file

On the line:

for($i=0;$i


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at a time. So, anything before || is treated as a different value and

anything after || is a different value.

We had written name of the user before || so to output the name we use:

$info[0] variable, which means output the value which occurs just before ||

and info[1] means that the value which occurs after the first || similarly if

we would have added some other information after email we may have

written it as:

fwrite($store,$name||$email||$any_other\n);

Then we can recall this $any_other value by:

$info[2]

and so on!

The line:

echo Name: $info[0]
Email: $info[1] ;

Outputs the name and email of each user.

It is not necessary to use || you can use any unique combination of

characters.

For example if you use @||@ as an identifier:

fwrite($store,$name@||@$email\n);

then you have to use:

$info = explode(@||@ , $data_file[$i]);

instead.

3.3 MySQL Databases

You have seen some useful features of TEXT based database, now lets

shift to MySQL database, MySQL database require that you have an

Now you have learnt how to make counters and user forms,dont just limit it to these two applications, you can createuncountable number of applications with these simple functionsthat have been described.


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existing MySQL enabled account on your server, you should have a

MySQL database name, a MySQL login username and a password.

If you see a MySQL Database option on your control panel it means that

your server has support for MySQL Database, you can create database

login username and password from your web hosting control panel.

Method of creating a database login username and password will not be

discussed here and can easily be found by searching this topic on

Internet.

Before we create any script, create a file conf.php and add the following

code in it:

In the above code, replace the value of $db_host value, i.e. localhost to

your own host, well, it is mostly localhost on most of the servers you may

not need to change it. Provide the value of your database name, i.e.

replace

db_nm to your own database name, similarly provide your database

username and password information, save this file. We will use this file for

connecting with database in script.

Now lets create your first MySQL Database script:

Let us start by making a search engine:


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$db=mysql_connect($db_host,$database_user,$database_pass) or

die("MySQL Error: Unable to connect to database please check that you

have provided the correct Database Login usernameDatabase Login

Password");

//Select the databasemysql_select_db($db_name,$db)or die("MySQL Error: Unable to select

database please check that you have provided the correct Database name");

//Create table if not exists

$sqlm= mysql_query("CREATE TABLE search_tbl(op INT NOT NULL

AUTO_INCREMENT PRIMARY KEY,name TEXT NOT NULL,email TEXT NOT

NULL,telephone INT(18) NOT NULL)");

echo "";

echo "ADD AN ENTRY
";echo "NAME:
";

echo "EMAIL:
";

echo "TELEPHONE:
";

echo "";

echo "";

//If action is add_entry

if($action=="add_entry"){

//Check whether all the fields are filled

if($email!="" && $name!="" && $tel!=""){

$insert=mysql_query("INSERT INTO search_tbl SET

name='$name',email='$email',telephone='$tel");

if($insert){

//If entry has been inserted into database, then output the message

echo "
Entry has been successfully added.";

}

}else{

echo "Please fill all the fields";

}

}

?>


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Save the above code as add.php

Make a file search.php and add the following code in it:


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}

}

?>

You can see that the upper part of the code is same that is:

//Load Database Login information file

include "conf.php";

//Connect to database or give error if failed

$db=mysql_connect($db_host,$database_user,$database_pass) or

die("MySQL Error: Unable to connect to database please check that you

have provided the correct Database Login usernameDatabase Login

Password");

//Select the database

mysql_select_db($db_name,$db)or die("MySQL Error: Unable to select

database please check that you have provided the correct Database name");

The first line:

include "conf.php";

Loads the file containing the database login information.

The second line connects to the database using the information containedin conf.php the third line selects the database to perform actions with the

database.

The code:

$sql2= mysql_query("CREATE TABLE search_tbl(op INT NOT NULL

AUTO_INCREMENT PRIMARY KEY,name TEXT NOT NULL,email TEXT NOT

NULL,telephone INT(18) NOT NULL)");

Creates a table named search_tbl if it does not exist. A table in MySQL

Database is a place where information can be stored in its rows and

columns. The table that has just been created using the above code

contains 4 columns, first column names op, the second column name is

name the third column name is email and the last column name is

telephone. We have also defined the data type in each of the column


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that is acceptable for it, the column op can only store integer values, NOT

NULL means that if no value is specified it will take some value by itself it

will not be left blank, AUTO_INCREMENT means that the value will

increase by one from the row above it. For example, If it was 1 in the row

above it then it will now be 2. The column name is TEXT type, that is, we

can store text as well as numeric values in it. Telephone is again INT but

we have here defined that int value can be as long as 18 characters.

From the next line of add.php, search entry addition form is created. The

next portion adds the search entry to the database.

The code:

$insert=mysql_query("INSERT INTO search_tbl SET

name='$name',email='$email',telephone='$tel);

Inserts the submitted information to the database, that is, it creates a new

row in the database and adds $name in column name, $email in column

email and $tel in column telephone.

Now lets discuss the code of search.php

The line:

$list=mysql_query("SELECT * FROM search_tbl WHERE name LIKE

'%$sname%'");

lists all the rows in the table search_tbl which have the name similar to

the $name variable.

The code:

$results=mysql_num_rows($list);

Counts all the rows which meet the search criteria.

Now we want the output of the searched rows for this purpose, while loop

has been used.

Which will continue until all the fetched rows have been processed.

For each searched row of the table, we define:

$row=mysql_fetch_array($list)


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so $row becomes an array, and we can now output our desired column

value, to show the output of the values of column name, email and

telephone, we use:

$row[name]

$row[email]

$row[telephone]

Of course to show the output we use it inside echo.

You can now create a MySQL Counter, instead of text-based database,

use MYSQL. You have to create table for the counter with two columns,

one containing hits statistics and the other containing the IP address of

the visitor.

Here is the MySQL counter Code:


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if($array[ip]==$user_ip){

$cstats=$array[stats];

}else{

//Add 1 to current stats

$cstats=$array[stats]+1;$updt=mysql_query(UPDATE counter SET ip=$user_ip,stats= $cstats);

}

//Output the Result

echo Total Number of visiors: $cstats;

?>


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Chapter

Image Handling

4 Image Handling

With PHP, you can create thumbnails, convert images into different

formats and even create your own images.

4.1 Basic Q and As

What are the requirements of server?

Your server must have GD library installed, most of the PHP supported

servers do have GD library installed.

4.2 Creating Thumbnails

Start by making the thumbnail script, here is the code for creating

thumbnails:


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imagegif($targetImage, $thumbPath."".$thumbName,100);

we can also output in jpg format by using:

imagejpeg($targetImage, $thumbPath."".$thumbName,100);

The last line outputs the thumbnail.

4.3 Converting images to different formats

With PHP, you can convert images into GIF, JPG or PNG format.

For this purpose, the same functions as used above will be used:

For example, lets say we want to convert main.jpg into png format, for this

purpose, we use the following code:

Since the target image size is same as that of the source image, so we

have used:

$image=getimagesize($sourceimg);

So, $image becomes an array, and width of the image is:

$ image[0]and height is$image[1]


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4.4 Creating your own images

PHP allows you to create your own images, it is very useful in generating

random numbers and alphabets which are used in signing up to prevent

Spam.

Follow the code below:

The line:

$background = imagecolorallocate($image, 255, 255, 255);

Specifies the background color of the image.

The line:

imagefilledrectangle($image, 1, 1, $width - 2, $height - 2, $background);Fills the image with the background color, leaving 1 px from the left, 1

from the top and 1 from the right and one from the bottom so that it

appears as a black border.

The following code:

imagestring ($image, 3, 5, 6, "This is Text", $textColor);


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Writes the text This is Text on the image 3 is the size of the text (It

ranges from 1 to 5), 5 is the left margin and 6 is the top margin.


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Chapter

PHP Sessions

5 PHP Sessions5.1 Basic Q and As

What is a PHP Session, what is the use of it?

With PHP Session, you can store arrays or variables between the script

executions. A session remains valid in a same browser window; if the

browser window is closed and script is reopened then previous session

no longer exists. Session is used to identify the user.

5.2 PHP Sessions

A PHP session requires initialization before it can store any information; it

can be initialized by using the following code:

session_start();


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echo You are successfully logged in
Logout;

}

}

?>

In the above code, you can see that the line that starts the session is:

session_start();

As mentioned earlier that this code comes before any output is sent.

Password of login is stored in variable $admin and its value is admin

If there is a request for logout then:

session_destroy();

the above function destroys the login session if it exists.Now if there is a request for logging in, then:

User input password is validated if password entered is equal to the

admin then a session variable is set:

$_SESSION['verify']=$pass;

The name of this session variable is verify and its value is the value of

password.

The code:if (!isset($_SESSION['verify'])){

checks whether any session variable having name verify exists or not, if

it does not exists then a user login form appears.

If the verify session variable exists, then the value of this variable is

matched with the password using code:

if($_SESSION['verify']==$pass){

If it matches then message You are successfully logged in is

displayed as well as a logout link, user can click this link to log out and

destroy the session.

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