(6/29/2009)
The audio book broadcast listings at
gutterstar.net/streaming have been updated. The new broadcast includes: Horizon Storms, by Kevin J. Anderson.
V3.1: Added: Display an optional advertisement for your site within a popup window to discourage hotlinking. To configure this feature, look in the stream_config.php file.
V3.0: Fix: Includes a large bug fix which corrects the calculation of the authorization code when generated towards the end of the month.
Introduction
To give you an example of what this PHP script actually does... The following link will trigger an M3U playlist to be dynamically created. (The streaming audio that is being indexed, is the same as is available from our Streaming Alternative Rock Page.) This will cause all of the MP3 audio files within a folder on the server to be indexed, dynamically written to an M3U file, then opened in your default media player!
That's right! These audio files are not being indexed from a static M3U playlist, but rather, are being generated from scratch based on the mp3 files within the audio folder itself. If any of the audio files are deleted, renamed, or more audio files are added, the changes will automatically be reflected within this dynamically generated M3U playlist.
As if this functionality weren't enough, check this out... When the M3U playlist is created, it includes an automatic timeout feature, which causes the audio stream to timeout after a set interval. The timeout length is totally customizable! For example, you could timeout the stream after 35 seconds, 1 hour and 2 minutes, 1 day and 3 hours, or whatever you like!
Even more, there are built in security features that prevent your listeners from being able to directly download your audio files, or even be able to tell where they are actually located on the server!
In the example implementation above, the current settings will cause the audio stream to time out after 1 hour has elapsed. This countdown will always start at the moment when the link for the script is activated, which will be different for each user. This functionality is truly awesome! When this time out occurs, the user will not be able to listen to anymore of the audio stream without reactivating the script. These settings are fully configurable however, to fit your needs.
How to Configure
To configure the script for your website, simply edit the file named "stream_config.php". An excerpt from the code contained within this file follows...
/*
To begin streaming mp3 audio from your website:
1. Configure the variables below.
2. Upload all of these files to the folder where you want to access the script. All should reside within the same logical folder.
3. Create a link to the file named "stream_gen_m3u.php"
*/
// The URL path of the folder where your audio files reside. This path must not end with a "/"
$url_path = 'http://domain.com/folder';
// The relative folder where the audio files are located. This path must start where this script originates, and point to the same location as indicated above. Must not end with a "/".
$folder_path = './folder';
// The extention of your audio files. This must not begin with a "."
$extension = 'mp3';
// The URL path that points to "stream.php"
$stream_url = 'http://domain.com/stream.php';
// The relative path and file name of the schedule script file. This should be fine if left within the same folder as "stream.php"
$schedule_file = './stream_schedule.php';
// The relative path and file name of the M3U file. This will automatically be created.
$m3u_file = './stream_m3u.m3u';
// Set how often the audio stream will expire, so visitors will have to return to your site to continue listening.
// The time will automatically be incremented by whatever numbers you specify below.
// As an example, the default value below, will cause the audio stream to timeout after 1 hour, 30 minutes, and 45 seconds after the script first runs.
// The specified number of months.
$time_months = 0;
// The specified number of days.
$time_days = 0;
// The specified number of hours.
$time_hours = 1;
// The specified number of minutes.
$time_minutes = 30;
// The specified number of seconds.
$time_seconds = 45;
// Encode string, this will encode the Authorization code to prevent tampering within the playlist.
// This string must consist of ten individual letters. You can also change the case of individual letters to increase the security.
// Make sure that there are no repeat characters, and no spaces.
$security_string = 'abcdefghij';
// After uploading this file, set the permission to deny all Read access. Usually 600 will work for this.
Further instructions are included within the download. Simply view the file named "Instructions.htm" for additional details.
PHP
Paradigm
imperative,
object-oriented
Appeared in
1995
Designed by
Rasmus Lerdorf
Developer
The PHP Group
Latest release
5.2.5/
8 November
2007
Typing discipline
Dynamic, weak
Influenced by
C,
Perl,
Java,
C++,
Python
OS
Cross-platform
License
PHP License
Website
http://php.net/
table end
PHP is a computer
scripting language
originally designed for producing
dynamic web pages.
[1]
The name PHP is a
recursive acronym
for PHP: Hypertext Preprocessor.
PHP is used mainly in
server-side scripting
, but can be used from a
command line interface
or in standalone
graphical applications.
Textual User Interfaces
can also be created using
ncurses.
The main implementation is produced by The PHP Group and released under the
PHP License
. This implementation serves to define a
de facto
standard for PHP, as there is no
formal specification
. The most recent version of PHP is 5.2.5, released on
8 November
2007
. It is considered to be
free software
by the
Free Software Foundation.
[2]
PHP was written as a set of
Common Gateway Interface
(CGI) binaries in the
C programming language
by the Danish/Greenlandic programmer
Rasmus Lerdorf
in 1994, to replace a small set of
Perl
scripts he had been using to maintain his
personal homepage.
[3]
Lerdorf initially created PHP to display his
résumé
and to collect certain data, such as how much traffic his page was receiving. Personal Home Page Tools was publicly released on
8 June
1995
after Lerdorf combined it with his own Form Interpreter to create PHP/FI (this release is considered PHP version 2).
[4]
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. 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.
[5]
They also founded
Zend Technologies
in
Ramat Gan
, Israel, which actively manages the development of PHP.
In May 2000, PHP 4, powered by the Zend Engine 1.0, was released. The most recent update released by The PHP Group, is for the older PHP version 4 code
branch which, as of
January 2008
, is up to version 4.4.8. PHP 4 will be supported by security updates until
August 8,
2008.
[6]
On
July 13,
2004
, PHP 5 was released powered by the new Zend Engine II. PHP 5 included new features such as:
[7]
• Improved support for
object-oriented programming
• The PHP Data Objects extension, which defines a lightweight and consistent interface for accessing databases
• Performance enhancements
• Better support for
MySQL
and
MSSQL
• Embedded support for
SQLite
• Integrated
SOAP
support
• Data
iterators
• Error handling via
exceptions
Currently, PHP 5.x is the only stable version that is being actively developed; active development on PHP 4 ceased at the end of
2007
. However, critical security updates for PHP 4 will be provided until
August 8,
2008.
[8]
PHP 6 is currently under development, and is slated to release in conjunction with the decommission of PHP 4.[citation needed]
As a result of the GoPHP5 initiative, many high profile open source projects ceased to support PHP 4 in new code as of
5 February
2008.
[9]
PHP is a widely-used general-purpose scripting language that is especially suited for
Web development
and can be embedded into HTML. PHP generally runs on a
web server
, taking PHP code as its input and creating Web pages as output. However, it can also be used for
command-line
scripting and
client-side
GUI
applications. PHP can be deployed on most
web servers
and on almost every
operating system
and
platform
free of charge. The PHP Group also provides the complete source code for users to build, customize and extend for their own use.
PHP primarily acts as a
filter
. The PHP program takes input from a file or stream containing text and special PHP instructions and outputs another stream of data for display.
From PHP 4, the PHP parser
compiles
input to produce
bytecode
for processing by the
Zend Engine
, giving improved performance over its
interpreter
predecessor. PHP 5 uses the Zend Engine II.
Originally designed to create dynamic web pages, PHP's principal focus is
server-side scripting
. While running the PHP
parser
with a
web server
and
web browser
, the PHP model can be compared to other server-side scripting languages such as
Microsoft
's
ASP.NET
system,
Sun Microsystems' JavaServer Pages
, and
mod perl
as they all provide dynamic content to the
client
from a web server. To more directly compete with the "framework" approach taken by these systems, Zend is working on the
Zend Framework
- an emerging (as of June 2006) set of PHP building blocks and best practices; other
PHP frameworks
along the same lines include
CakePHP,
PRADO
and
Symfony.
The
LAMP
architecture has become popular in the Web industry as a way of deploying inexpensive, reliable, scalable, secure web applications. PHP is commonly used
as the P in this bundle alongside
Linux,
Apache
and
MySQL
, although the P can also refer to
Python
or
Perl
. PHP can be used with a large number of
relational database management systems
, runs on all of the most popular web servers and is available for many different
operating systems
. This flexibility means that PHP has a wide installation base across the Internet;
As of April 2007
, over 20 million Internet domains were hosted on servers with PHP installed.
[10]
The number of installations is different from the number of sites actually using those installations, but this statistic does reflect the popularity of
PHP.
Examples of popular open source server-side PHP applications include
phpBB,
WordPress
, and
MediaWiki.
PHP also provides a
command line interface
SAPI
for developing shell and desktop applications, daemons, log parsing, or other system administration tasks that have traditionally been the domain of
Perl,
Python,
awk
, or
shell scripting.
[11]
PHP provides bindings to
GUI
libraries such as
GTK+
(with
PHP-GTK),
Qt
with PHP-Qt and text mode libraries like
ncurses
in order to facilitate development of a broader range of
cross-platform
GUI applications.
As with many scripting languages, PHP scripts are normally kept as human-readable source code, even on production webservers. While this allows flexibility,
it can raise issues with security and performance.
Encoders hinder source code
reverse engineering
. Encoders fall broadly into two types; those that hide source code and those that compile code into "optcode."[citation needed]
The downside of this latter approach is that a special extension has to be installed on the server in order to run encoded scripts, however the approach
of encoding compiled code and use of an extension offers typically the best performance, security and opportunity for additional features that may be useful
for developers. Compiled code solutions may exploit the potential for increased security through the use of their own execution engine, although some simpler
solutions rely on the regular PHP engine to execute the compiled code. The most commonly used packages for source code protection are from
Zend Technologies
and
ionCube Ltd.
Code optimizers improve the quality of the compiled code by reducing its size and making changes that can reduce the execution time and improve performance.
The nature of the PHP
compiler
is such that there are often many opportunities for
code optimization.
Accelerators offer 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. They may also perform
code optimization
to provide increased execution performance. Both commercial (e.g. Zend Platform) and open source accelerators (e.g. xcache, eAccelerator, APC) are available.
The
PHP Extension and Application Repository
(PEAR) project aims to provide reusable libraries and components for PHP development. PEAR projects are usually written in PHP code using the
Object-oriented programming
paradigm.
PHP has a formal development manual that is maintained by the
free software community
. In addition, answers to many questions can often be found by doing a simple internet search. PHP users assist each other through various media such as
chat, forums, newsgroups and PHP developer web sites. In turn, the PHP development team actively participates in such communities, garnering assistance
from them in their own development effort (PHP itself) and providing assistance to them as well. There are many help resources
[14]
available for the novice PHP programmer.
