LITERATURE REVIEW
Hostel management system development using PHP program has lots of codes, Using Internet in gathering information partially contributed to the success of this project. Due to the fact that PHP is an open source program, development of hostel management system was not too difficult. However, thanks to the cyber world (Internet) that makes it possible to study and make comparison in needs of some code function.
Numbers of hostel management system documents were examine and compare to the need of Rufus Giwa Polytechnic proposed hostel management system. For instance, Hostel Management System by Cochin University of Science and Technology Division of Computer Engineering Centre for Engineering Studies Cochin-682022, help in my initial research of hostel management system application.
Among other web site that was used in my research is freesourcecode.com. It provided me with different codes which I used in the development of this program
Using
of textbooks and journal on the net was also a great source of
information and assistance in realizing the goal of this project. For
instance, "A review of PHP compilers and their outputs" Favre, Nicolas (2010-02-16) gave a good layout of product design. Also, Personal Home Page Tools (PHP Tools) Lerdorf, Rasmus (1995-06-08), was very helpful and supportive in the product development of the pages of this project.
2.1 SYSTEM ENVIRONMENT
2.2 Software Configuration
1. OS : Windows 7
2.Wamp server (PHP, MySQL, and PHPMyAdmin)
2.2.1 Software Features
2.2.2 Wamp server
Wamp
server installs a complete working PHP/MySQL server environment on
Windows platforms (9x/ NT). Installs PHP, MySQL, Apache, and PHPMyAdmin.
2.2.2.1PHP
PHP is
a scripting language originally developed for producing dynamic web
pages. It has evolved to include a command line interface capability and
can be used in standalone graphical applications. While PHP was
originally created by Rasmus Lerdorf in 1995, the main implementation of
PHP is now produced by The PHP Group and serves as the de facto standard
for PHP as there is no formal specification. PHP is free software
released under the PHP License, however it is incompatible with the GNU
General Public License (GPL), due to restrictions on the usage of the term PHP. It is a widely-used general-purpose scripting language that is especially suited for web development and can be embedded into HTML. It generally runs on a web server, taking PHP code as its input and creating web pages as output. It can be deployed on most web servers and on almost every operating system and platform free of charge. PHP is installed on more than 20 million websites and 1 million web servers.
PHP originally
stood for Personal Home Page. It began in 1994 as a set of Common
Gateway Interface binaries written in the C programming language by the
Danish/Greenlandic programmer Rasmus Lerdorf. Lerdorf initially created
these Personal Home Page Tools to replace a small set of Perl scripts he
had been using to maintain his personal homepage. The tools were used
to perform tasks such as displaying his résumé and recording how much traffic his
page was receiving. He combined these binaries with his Form
Interpreter to create PHP/FI, which had more functionality. PHP/FI
included a larger implementation for the C programming language and
could communicate with databases, enabling the building of simple,
dynamic web applications. Lerdorf released PHP publicly on June 8, 1995
to accelerate bug location and improve the code. This release was named
PHP version 2 and already had the basic functionality that PHP has
today. This included Perl-like variables, form handling, and the ability
to embed HTML. The syntax was similar to Perl but was more limited,
simpler, and less consistent. Zeev Suraski and Andi Gutmans, two Israeli
developers at the Technion IIT, rewrote the parser in 1997 and formed
the base of PHP 3, changing the language’s name to the recursive
initialism PHP: Hypertext Preprocessor.
The development team officially released PHP/FI 2 in November 1997
after months of beta testing. Afterwards, public testing of PHP 3 began,
and the official launch came in June 1998. Suraski and Gutmans then
started a new rewrite of PHP’s core, producing the Zend Engine in 1999.
They also founded Zend Technologies in Ramat Gan, Israel. On May 22,
2000, PHP 4, powered by the Zend Engine 1.0, was released. On July 13,
2004, PHP 5 was released, powered by the new Zend Engine II. PHP 5
included new features such as improved support for object-oriented
programming, the PHP Data Objects extension (which defines a lightweight
and consistent interface for accessing databases), and numerous
performance enhancements. The most recent update released by The PHP
Group is for the older PHP version 4 code branch.
In
2008, PHP 5 became the only stable version under development. Late
static binding has been missing from PHP and will be added in version
5.3. PHP 6 is under development alongside PHP 5. Major changes include
the removal of register globals, magic quotes, and safe mode. The reason
for the removals was because register globals had given way to security
holes, and magic quotes had an unpredictable nature, and was best
avoided. Instead, to escape characters, Magic quotes may be substituted
with the addslashes() function, or more appropriately an escape
mechanism specific to the database vendor itself like
mysql_real_escape_string() for MySQL.
PHP
does not have complete native support for Unicode or multibyte strings;
Unicode support will be included in PHP 6. Many high profile open
source projects ceased to support PHP 4 in new code as of February 5,
2008, due to the GoPHP5 initiative, provided by a consortium of PHP
developers promoting the transition from PHP 4 to PHP 5. It runs in both
32-bit and 64-bit environments, but on Windows the only official
distribution is 32-bit, requiring Windows 32-bit compatibility mode to
be enabled while using IIS in a 64-bit Windows environment. There is a
third-party distribution available for 64-bit Windows.
Usage
PHP
is a general-purpose scripting language that is especially suited for
web development. PHP generally runs on a web server, taking PHP code as
its input and creating web pages as output. It can also be used for
command-line scripting and client-side GUI applications. PHP can be
deployed on most web servers, many
operating
systems and platforms, and can be used with many relational database
management systems. It is available free of charge, and the PHP Group
provides the complete source code for users to build, customize and
extend for their own use. PHP primarily acts as a filter, taking input
from a file or stream containing text and/or PHP instructions and
outputs another stream of data; most commonly the output will be HTML.
It can automatically detect the language of the user. From PHP 4, the
PHP parser compiles input to produce byte code for processing by the
Zend Engine, giving improved performance over its interpreter
predecessor. Originally designed to create dynamic web pages, PHP’s
principal focus is server-side scripting, and it is similar to other
server-side scripting languages that provide dynamic content from a web
server to a client, such as Microsoft’s Active Server Pages, Sun
Microsystems’ JavaServer
Pages, and mod_perl. PHP has also attracted the development of many
frameworks that provide building blocks and a design structure to
promote rapid application development (RAD). Some of these include
CakePHP, Symfony, CodeIgniter, and Zend Framework, offering features
similar to other web application frameworks. The LAMP architecture has
become popular in the web industry as a way of deploying web
applications.
PHP is commonly used as the P in this bundle alongside Linux, Apache and MySQL, although the P may also refer to Python or Perl.
As
of April 2007, over 20 million Internet domains were hosted on servers
with PHP installed, and PHP was recorded as the most popular Apache
module. Significant websites are written in PHP including the user
facing portion of Facebook, Wikipedia (MediaWiki), Yahoo!, MyYearbook, ,
Digg, Wordpress and Tagged.
In
addition to server-side scripting, PHP can be used to create
stand-alone, compiled applications and libraries, it can be used for
shell scripting, and the PHP binaries can be called from the command
line.
2.2.2.1.1 Speed optimization
As
with many scripting languages, PHP scripts are normally kept as
human-readable source code, even on production web servers. In this
case, PHP scripts will be compiled at runtime by the PHP engine, which
increases their execution time. PHP scripts are able to be compiled
before runtime using PHP compilers as with other programming languages
such as C (the language PHP and its extensions are written in). Code
optimizers aim to reduce the computational complexity of the compiled
code by reducing its size and making other changes that can reduce the
execution time with the overall goal of improving performance. The
nature of the
PHP
compiler is such that there are often opportunities for code
optimization, and an example of a code optimizer is the Zend Optimizer
PHP extension.
Another
approach for reducing overhead for high load PHP servers is using PHP
accelerators. These can offer significant performance gains by caching
the compiled form of a PHP script in shared memory to avoid the overhead
of parsing and compiling the code every time the script runs.
2.2.2.1.2 Security
The
National Vulnerability Database stores all vulnerabilities found in
computer software. The overall proportion of PHP-related vulnerabilities
on the database amounted to: 12% in 2003, 20% in 2004, 28% in 2005, 43%
in 2006, 36% in 2007, and 35% in 2008. Most of these PHP-related
vulnerabilities can be exploited remotely: they allow hackers to steal
or destroy data from data sources linked to the webserver
(such as an SQL database), send spam or contribute to DOS attacks using
malware, which itself can be installed on the vulnerable servers.
These
vulnerabilities are caused mostly by not following best practice
programming rules: technical security flaws of the language itself or of
its core libraries are not frequent. Recognizing that programmers
cannot be trusted, some languages include taint checking to detect
automatically the lack of input validation which induces many issues.
However, such a feature is being developed for PHP Hosting PHP applications on a server require
a careful and constant attention to deal with these security risks.
There are advanced protection patches such as Suhosin and
Hardening-Patch, especially designed for web hosting environments.
Installing PHP as a CGI binary rather than as an Apache module is the
preferred method for added security. With respect to securing the code
itself, PHP code can be obfuscated to make it difficult to read while
remaining functional.
2.2.2.1.4 Data types
PHP
stores whole numbers in a platform-dependent range. This range is
typically that of 32-bit signed integers. Unsigned integers are
converted to signed values in certain situations; this behavior is
different from other programming languages. Integer variables can be
assigned using decimal (positive and negative), octal,
and
hexadecimal notations. Floating point numbers are also stored in a
platform-specific range. They can be specified using floating point
notation, or two forms of scientific notation. PHP has a native Boolean
type that is similar to the native Boolean types in Java and C++. Using
the Boolean type conversion rules, non-zero values are interpreted as
true and zero as false, as in Perl and C++. The null data type
represents a variable that has no value.
The only value in the null data type is NULL. Variables
of the “resource” type represent references to resources from external
sources. These are typically created by functions from a particular
extension, and can only be processed by functions from the same
extension; examples include file, image, and database resources.
Arrays
can contain elements of any type that PHP can handle, including
resources, objects, and even other arrays. Order is preserved in lists
of values and in hashes with both keys and values, and the two can be
intermingled. PHP also supports strings, which can be used with single
quotes, double quotes, or heredoc
syntax.
The Standard PHP Library (SPL) attempts to solve standard problems and
implements efficient data access interfaces and classes.
2.2.2.1.5 Functions
PHP
has hundreds of base functions and thousands more from extensions.
These functions are well documented on the PHP site, but unfortunately,
the built-in library has a wide variety of naming conventions and
inconsistencies. PHP currently has no functions for thread programming.
Version 5.2 and earlier
Functions
are not first-class functions and can only be referenced by their name
directly or dynamically by a variable containing the name of the
function. User-defined functions can be created at any time without
being prototyped. Functions can be defined inside code blocks,
permitting a run-time decision as to whether or not a function should be
defined. Function calls must use parentheses, with the exception of
zero argument class constructor functions called with the PHP new
operator, where parentheses are optional. PHP supports quasi-anonymous
functions through the create_function() function, although they are not
true anonymous functions because anonymous functions are nameless, but
functions can only be referenced by name, or indirectly through a
variable $function_name();, in PHP.
Version 5.3 and newer
PHP gained support for first-class functions and closures. True anonymous functions are supported function getAdder($x) using the following syntax :
{
function getAdder($x)
{
return function ($y) use ($x) {
return $x + $y;
};
}
$adder = getAdder(8);
echo $adder(2); // prints “10”
Here, getAdder()
function creates a closure using parameter $x (keyword “use” forces
getting variable from context), which takes additional argument $y and
returns it to the caller. Such a function can be stored, given as the
parameter to another functions, etc. For more details see Lambda
functions and closures RFC.
2.2.2.1.6 Objects
Basic
object-oriented programming functionality was added in PHP 3. Object
handling was completely rewritten for PHP 5, expanding the feature set
and enhancing performance. In previous versions of PHP, objects were
handled like primitive types. The drawback of this method was that the
whole object was copied
when
a variable was assigned or passed as a parameter to a method. In the
new approach, objects are referenced by handle, and not by value. PHP 5
introduced private and protected member variables and methods, along
with abstract classes and final classes as well as abstract methods and
final methods. It also introduced a standard way of declaring
constructors and destructors, similar to that of other object-oriented
languages such as C++, and a standard exception handling model.
Furthermore, PHP 5 added interfaces and allowed for multiple interfaces
to be implemented. There are special interfaces that allow objects to
interact with the runtime system. Objects implementing Array Access can
be used with array syntax and objects implementing Iterator or Iterator
Aggregate can be used. There is no virtual table feature in the engine,
so static variables are bound with a name instead of a reference at
compile time.
If the developer creates a copy of an object using the reserved word clone, the Zend engine will check if a __clone () method has been defined or not. If not, it will call a default __ clone () which will copy the object’s properties. If a __clone ()
method is defined, then it will be responsible for setting the
necessary properties in the created object. For convenience, the engine
will supply a function that imports the properties of the source object,
so that the programmer can start with a by-value replica of the source
object and only override properties that need to be changed.
2.2.2.1.7 Resources
PHP
includes free and open source libraries with the core build. PHP is a
fundamentally Internet aware system with modules built in for accessing
FTP servers, many database servers, embedded SQL libraries such as
embedded PostgreSQL, MySQL and SQLite, LDAP servers, and others. Many
functions familiar to C programmers such as those in the stdio
family are available in the standard PHP build. PHP has traditionally
used features such as “magic_quotes_gpc” and “magic_quotes_runtime”
which attempt to escape apostrophes (‘) and quotes (“) in strings in the
assumption that they will be used in databases, to prevent SQL
injection attacks. This leads to confusion over which data is escaped
and which is not, and to problems when data is not in fact used as input
to a database and when the escaping used is not completely correct. To
make code portable between servers which do and do not use magic quotes,
developers can preface their code with a script to reverse the effect
of magic quotes when it is applied.
PHP
allows developers to write extensions in C to add functionality to the
PHP language. These can then be compiled into PHP or loaded dynamically
at runtime. Extensions have been written to add support for the Windows
API, process management on Unix-like operating systems, multi-byte
strings (Unicode), cURL,
and
several popular compression formats. Some more unusual features include
integration with Internet Relay Chat, dynamic generation of images and
Adobe Flash content, and even speech synthesis. The PHP Extension
Community Library (PECL) project is a repository for extensions to the
PHP language. Zend provides a certification exam for programmers to
become certified PHP developers.
2.2.2.2 MY SQL
What
is a database? Quite simply, it’s an organized collection of data. A
database management system (DBMS) such as Access, FileMaker Pro, Oracle
or SQL Server provides you with the software tools you need to organize
that data in a flexible manner. It includes facilities to add, modify or
delete data from the
database, ask questions (or queries) about the data stored in the database and produce reports summarizing selected contents.
MySQL
is a multi-threaded, multi-user SQL database management system(DBMS).
The basic program runs as a server providing multi-user access to a
number of databases. Originally financed in a similar fashion to the
JBoss model, MySQL was owned and sponsored by a single for-profit firm,
the Swedish company
MySQLAB
now a subsidiary of Sun Micro system, which holds the copyright to most
of the code base. The project’s source code is available under terms of
the GNU General Public License, as well as under a variety
of
proprietary agreements. MySQL is a database. The data in MySQL is
stored in database objects called tables. A table is a collection 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”.
2.2.2.2.1 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.
2.2.2.2.2 Queries
A query is a question or a request. With MySQL, a database can queried for a specific information and have a record set returned.
2.2.2.2.2.1 Create a connection to a database
Before a database can be created, a connection to the database should be created first. In PHP, this is done with the mysql_connect() function.
An example of how to create a connection to a database will be found in APPENDIX 2.
