Linux.Desktop.Hacks [Electronic resources] نسخه متنی

Hack 62. Get Browser Plug-ins Working

Liven up the Web with a plug-in or
two.

The Web has long moved beyond its humble beginnings as a text-based
medium. Now it is filled with dynamic content that includes
animations, interactivity, video, sound, and other types of media.
Special software, known as plug-ins, is usually required to use this
new content. Getting plug-ins to work in Firefox can be a little
difficult, so this hack explores how to get the two most common
plug-ins working: Macromedia Flash and Java.

8.9.1. Use the Macromedia Flash Plug-in

The Macromedia Flash plug-in enables you to view animations on
dynamic web sites. A few years back, installing Flash was a difficult
and error-prone process, but luckily, the process has improved.
First, download the Linux Flash plug-in from http://www.macromedia.com, and unzip it into
a directory. Once it is extracted, you will see a number of files,
including a file called flashplayer-installer.
This file automates the process of installing Flash.

Before you can run the installer, you must change its permissions so
that it is executable:

foo@bar:~$ chmod a+x flashplayer-installer

To run the installer and have it install the plug-in for you, type
the following command:

foo@bar:~$ ./flashplayer-installer

Once you have run through this installation routine, load up Firefox
and type the following into the address bar:

about:plugins

This page tells you the plug-ins Firefox has installed. Once
you've installed the Flash plug-in, you should see
two entries that look like this:

MIME Type

Description

Suffixes

Enabled

application/x-shockwave-flash

Shockwave Flash

swf

Yes

application/futuresplash

FutureSplash Player

spl

Yes

These two lines indicate that the player is correctly installed. Now
you can test the player by visiting a Flash-based web site, such as
the "fantastic" http://www.badgerbadgerbadger.com.

8.9.2. Use Java in Firefox

Java is a popular cross-platform programming environment in
which you can theoretically write a single program, and have it run
on a number of different operating systems and web browsers. Although
the Java language was developed by Sun Microsystems, it has been
licensed openly enough to allow a number of Java software
interpreters to be developed by various companies and organizations.

To run Java programs, you need a Java Runtime Environment (JRE). This
software lets you run Java programs either in a web browser or as a
normal application. By far one of the most popular JREs available is
from Sun at http://java.sun.com/j2se/. Other Java
environments are available that work well with Firefox and normal
Java desktop environments, but this hack covers just the official Sun
incarnation.

One issue to bear in mind in terms of getting the right JRE is
finding one that is compatible with Firefox. The first place you
should check for this information is http://plugindoc.mozdev.org/. Traditionally,
in terms of using Java within Firefox, the main source of problems is
that the browser should be compiled with the same major version of
the GNU C Compiler as the versions of the JRE you will be using. At
the time of this writing, Firefox requires version 1.4.2 or later of
the Sun JRE, as this version and most distributed versions of Firefox
were compiled with version 3 of the GNU C Compiler. You can check
which version your Firefox was compiled with by typing this into the
address bar:

about:buildconfig

It is likely that your version of the browser was compiled with GCC
3.x and should be compatible with the Sun JRE 1.4.2 or above.

When you have downloaded and installed the Sun JRE, you will have a
directory with all the files that are part of the JRE distribution.
Inside this is a plugins directory. To enable
Java support in Firefox, you need to create a symbolic link inside
your Mozilla plug-ins directory. The actual file in the JRE that you
are linking to is libjavaplugin_oji.so. You can
create this link by going to your Mozilla plug-ins directory in your
home directory (this should be .mozilla/plugins
or .firefox/plugins), and type in the following
command:

foo@bar:~$ ln -s /sources/jre/plugin/i386/ns610-gcc32/libjavaplugin_oji.so

This command assumes your JRE is in
/sources/jre; you will need to adjust it for the
actual directory on your machine. One point to note is that inside
the /sources/jre/plugin/i386 directory are a
number of subdirectories which correspond to different versions of
Netscape. The ns610-gcc32 directory contains the
correct plug-in for recent versions of Mozilla-based browsers (such
as Firefox). If you want to make Java support available to every user
on the system, you will need to make the symlink available in the
system Mozilla plugins directory (such as
/usr/lib/mozilla-firefox/plugins) as opposed to
a particular user's plug-ins directory.

You can check that your installation works by typing this into the
address bar:

about:plugins

You should see a number of lines showing that Java support is
working. Then you can test the installation by accessing a web site
that uses Java, such as http://java.sun.com/.