Java(tm) Binary Kernel Support for Linux v1.02
               ----------------------------------------------

Linux beats them ALL! While all other OS's are TALKING about direct
support of Java Binaries in the OS, Linux is doing it!

You can execute Java applications and Java Applets just like any
other program after you have done the following:

1) You MUST FIRST install the Java Developers Kit for Linux.
   The Java on Linux HOWTO gives the details on getting and
   installing this. This HOWTO can be found at:

        ftp://sunsite.unc.edu/pub/Linux/docs/HOWTO/Java-HOWTO

   You should also set up a reasonable CLASSPATH environment
   variable to use Java applications that make use of any
   nonstandard classes (not included in the same directory
   as the application itself).

2) You have to compile BINFMT_MISC either as a module or into
   the kernel (CONFIG_BINFMT_MISC) and set it up properly.
   If you choose to compile it as a module, you will have
   to insert it manually with modprobe/insmod, as kerneld
   can not easy be supported with binfmt_misc. 
   Read the file 'binfmt_misc.txt' in this directory to know
   more about the configuration process.

3) Add the following configuration items to binfmt_misc
   (you should really have read binfmt_misc.txt now):
   support for Java applications:
     ':Java:M::\xca\xfe\xba\xbe::/usr/local/java/bin/javawrapper:'
   support for Java Applets:
     ':Applet:E::html::/usr/local/java/bin/appletviewer:'
   or the following, if you want to be more selective:
     ':Applet:M::<!--applet::/usr/local/java/bin/appletviewer:'

   Of cause you have to fix the path names, if you installed the JDK
   at another place than /usr/local/java.

   Note, that for the more selective applet support you have to modify
   existing html-files to contain <!--applet--> in the first line
   ('<' has to be the first character!) to let this work!

   For the compiled Java programs you need a wrapper script like the
   following (this is because Java is broken in case of the filename
   handling), again fix the path names, both in the script and in the
   above given configuration string:

====================== Cut here ===================
#!/bin/bash
# /usr/local/java/bin/javawrapper - the wrapper for binfmt_misc/java
CLASS=$1

# if classname is a link, we follow it (this could be done easier - how?)
if [ -L "$1" ] ; then
        CLASS=`ls --color=no -l $1 | tr -s '\t ' '  ' | cut -d ' ' -f 11`
fi
CLASSN=`basename $CLASS .class`
CLASSP=`dirname $CLASS`

FOO=$PATH
PATH=$CLASSPATH
if [ -z "`type -p -a $CLASSN.class`" ] ; then
        # class is not in CLASSPATH
        if [ -e "$CLASSP/$CLASSN.class" ] ; then
                # append dir of class to CLASSPATH
                if [ -z "${CLASSPATH}" ] ; then
                        export CLASSPATH=$CLASSP
                else
                        export CLASSPATH=$CLASSP:$CLASSPATH
                fi
        else
                # uh! now we would have to create a symbolic link - really
                # ugly, i.e. print a message that one has to change the setup
                echo "Hey! This is not a good setup to run $1 !"
                exit 1
        fi
fi
PATH=$FOO

shift
/usr/local/java/bin/java $CLASSN "$@"
====================== Cut here ===================


Now simply chmod +x the .class and/or .html files you want to execute.
To add a Java program to your path best put a symbolic link to the main
.class file into /usr/bin (or another place you like) omitting the .class
extension. The directory containing the original .class file will be
added to your CLASSPATH during execution.


To test your new setup, enter in the following simple Java app, and name
it "HelloWorld.java":

        class HelloWorld {
                public static void main(String args[]) {
                        System.out.println("Hello World!");
                }
        }

Now compile the application with:
        javac HelloWorld.java

Set the executable permissions of the binary file, with:
        chmod 755 HelloWorld.class

And then execute it:
        ./HelloWorld.class


To execute Java Applets, simple chmod the *.html files to include
the execution bit, then just do
        ./Applet.html


originally by Brian A. Lantz, brian@lantz.com
heavily edited for binfmt_misc by Richard Günther.