[mirror_ubuntu-artful-kernel.git] / Documentation / java.txt

               Java(tm) Binary Kernel Support for Linux v1.03
               ----------------------------------------------

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 kmod
   cannot easily 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/bin/javawrapper:'
   support for executable Jar files:
     ':ExecutableJAR:E::jar::/usr/local/bin/jarwrapper:'
   support for Java Applets:
     ':Applet:E::html::/usr/bin/appletviewer:'
   or the following, if you want to be more selective:
     ':Applet:M::<!--applet::/usr/bin/appletviewer:'

   Of cause you have to fix the path names. Given path/file names in this
   document match the Debian 2.1 system. (i.e. jdk installed in /usr,
   custom wrappers from this document in /usr/local)

   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.

   You, too, need the little program after the script. Compile like
   gcc -O2 -o javaclassname javaclassname.c
   and stick it to /usr/local/bin.

   Both the javawrapper shellscript and the javaclassname program
   were supplied by Colin J. Watson <cjw44@cam.ac.uk>.

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

if [ -z "$1" ]; then
	exec 1>&2
	echo Usage: $0 class-file
	exit 1
fi

CLASS=$1
FQCLASS=`/usr/local/bin/javaclassname $1`
FQCLASSN=`echo $FQCLASS | sed -e 's/^.*\.\([^.]*\)$/\1/'`
FQCLASSP=`echo $FQCLASS | sed -e 's-\.-/-g' -e 's-^[^/]*$--' -e 's-/[^/]*$--'`

# for example:
# CLASS=Test.class
# FQCLASS=foo.bar.Test
# FQCLASSN=Test
# FQCLASSP=foo/bar

unset CLASSBASE

declare -i LINKLEVEL=0

while :; do
	if [ "`basename $CLASS .class`" == "$FQCLASSN" ]; then
		# See if this directory works straight off
		cd -L `dirname $CLASS`
		CLASSDIR=$PWD
		cd $OLDPWD
		if echo $CLASSDIR | grep -q "$FQCLASSP$"; then
			CLASSBASE=`echo $CLASSDIR | sed -e "s.$FQCLASSP$.."`
			break;
		fi
		# Try dereferencing the directory name
		cd -P `dirname $CLASS`
		CLASSDIR=$PWD
		cd $OLDPWD
		if echo $CLASSDIR | grep -q "$FQCLASSP$"; then
			CLASSBASE=`echo $CLASSDIR | sed -e "s.$FQCLASSP$.."`
			break;
		fi
		# If no other possible filename exists
		if [ ! -L $CLASS ]; then
			exec 1>&2
			echo $0:
			echo "  $CLASS should be in a" \
			     "directory tree called $FQCLASSP"
			exit 1
		fi
	fi
	if [ ! -L $CLASS ]; then break; fi
	# Go down one more level of symbolic links
	let LINKLEVEL+=1
	if [ $LINKLEVEL -gt 5 ]; then
		exec 1>&2
		echo $0:
		echo "  Too many symbolic links encountered"
		exit 1
	fi
	CLASS=`ls --color=no -l $CLASS | sed -e 's/^.* \([^ ]*\)$/\1/'`
done

if [ -z "$CLASSBASE" ]; then
	if [ -z "$FQCLASSP" ]; then
		GOODNAME=$FQCLASSN.class
	else
		GOODNAME=$FQCLASSP/$FQCLASSN.class
	fi
	exec 1>&2
	echo $0:
	echo "  $FQCLASS should be in a file called $GOODNAME"
	exit 1
fi

if ! echo $CLASSPATH | grep -q "^\(.*:\)*$CLASSBASE\(:.*\)*"; then
	# class is not in CLASSPATH, so prepend dir of class to CLASSPATH
	if [ -z "${CLASSPATH}" ] ; then
		export CLASSPATH=$CLASSBASE
	else
		export CLASSPATH=$CLASSBASE:$CLASSPATH
	fi
fi

shift
/usr/bin/java $FQCLASS "$@"
====================== Cut here ===================


====================== Cut here ===================
/* javaclassname.c
 *
 * Extracts the class name from a Java class file; intended for use in a Java
 * wrapper of the type supported by the binfmt_misc option in the Linux kernel.
 *
 * Copyright (C) 1999 Colin J. Watson <cjw44@cam.ac.uk>.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <sys/types.h>

/* From Sun's Java VM Specification, as tag entries in the constant pool. */

#define CP_UTF8 1
#define CP_INTEGER 3
#define CP_FLOAT 4
#define CP_LONG 5
#define CP_DOUBLE 6
#define CP_CLASS 7
#define CP_STRING 8
#define CP_FIELDREF 9
#define CP_METHODREF 10
#define CP_INTERFACEMETHODREF 11
#define CP_NAMEANDTYPE 12

/* Define some commonly used error messages */

#define seek_error() error("%s: Cannot seek\n", program)
#define corrupt_error() error("%s: Class file corrupt\n", program)
#define eof_error() error("%s: Unexpected end of file\n", program)
#define utf8_error() error("%s: Only ASCII 1-255 supported\n", program);

char *program;

long *pool;

u_int8_t read_8(FILE *classfile);
u_int16_t read_16(FILE *classfile);
void skip_constant(FILE *classfile, u_int16_t *cur);
void error(const char *format, ...);
int main(int argc, char **argv);

/* Reads in an unsigned 8-bit integer. */
u_int8_t read_8(FILE *classfile)
{
	int b = fgetc(classfile);
	if(b == EOF)
		eof_error();
	return (u_int8_t)b;
}

/* Reads in an unsigned 16-bit integer. */
u_int16_t read_16(FILE *classfile)
{
	int b1, b2;
	b1 = fgetc(classfile);
	if(b1 == EOF)
		eof_error();
	b2 = fgetc(classfile);
	if(b2 == EOF)
		eof_error();
	return (u_int16_t)((b1 << 8) | b2);
}

/* Reads in a value from the constant pool. */
void skip_constant(FILE *classfile, u_int16_t *cur)
{
	u_int16_t len;
	int seekerr = 1;
	pool[*cur] = ftell(classfile);
	switch(read_8(classfile))
	{
	case CP_UTF8:
		len = read_16(classfile);
		seekerr = fseek(classfile, len, SEEK_CUR);
		break;
	case CP_CLASS:
	case CP_STRING:
		seekerr = fseek(classfile, 2, SEEK_CUR);
		break;
	case CP_INTEGER:
	case CP_FLOAT:
	case CP_FIELDREF:
	case CP_METHODREF:
	case CP_INTERFACEMETHODREF:
	case CP_NAMEANDTYPE:
		seekerr = fseek(classfile, 4, SEEK_CUR);
		break;
	case CP_LONG:
	case CP_DOUBLE:
		seekerr = fseek(classfile, 8, SEEK_CUR);
		++(*cur);
		break;
	default:
		corrupt_error();
	}
	if(seekerr)
		seek_error();
}

void error(const char *format, ...)
{
	va_list ap;
	va_start(ap, format);
	vfprintf(stderr, format, ap);
	va_end(ap);
	exit(1);
}

int main(int argc, char **argv)
{
	FILE *classfile;
	u_int16_t cp_count, i, this_class, classinfo_ptr;
	u_int8_t length;

	program = argv[0];

	if(!argv[1])
		error("%s: Missing input file\n", program);
	classfile = fopen(argv[1], "rb");
	if(!classfile)
		error("%s: Error opening %s\n", program, argv[1]);

	if(fseek(classfile, 8, SEEK_SET))  /* skip magic and version numbers */
		seek_error();
	cp_count = read_16(classfile);
	pool = calloc(cp_count, sizeof(long));
	if(!pool)
		error("%s: Out of memory for constant pool\n", program);

	for(i = 1; i < cp_count; ++i)
		skip_constant(classfile, &i);
	if(fseek(classfile, 2, SEEK_CUR))	/* skip access flags */
		seek_error();

	this_class = read_16(classfile);
	if(this_class < 1 || this_class >= cp_count)
		corrupt_error();
	if(!pool[this_class] || pool[this_class] == -1)
		corrupt_error();
	if(fseek(classfile, pool[this_class] + 1, SEEK_SET))
		seek_error();

	classinfo_ptr = read_16(classfile);
	if(classinfo_ptr < 1 || classinfo_ptr >= cp_count)
		corrupt_error();
	if(!pool[classinfo_ptr] || pool[classinfo_ptr] == -1)
		corrupt_error();
	if(fseek(classfile, pool[classinfo_ptr] + 1, SEEK_SET))
		seek_error();

	length = read_16(classfile);
	for(i = 0; i < length; ++i)
	{
		u_int8_t x = read_8(classfile);
		if((x & 0x80) || !x)
		{
			if((x & 0xE0) == 0xC0)
			{
				u_int8_t y = read_8(classfile);
				if((y & 0xC0) == 0x80)
				{
					int c = ((x & 0x1f) << 6) + (y & 0x3f);
					if(c) putchar(c);
					else utf8_error();
				}
				else utf8_error();
			}
			else utf8_error();
		}
		else if(x == '/') putchar('.');
		else putchar(x);
	}
	putchar('\n');
	free(pool);
	fclose(classfile);
	return 0;
}
====================== Cut here ===================


====================== Cut here ===================
#!/bin/bash
# /usr/local/java/bin/jarwrapper - the wrapper for binfmt_misc/jar

java -jar $1
====================== Cut here ===================


Now simply chmod +x the .class, .jar 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 Jar files, simple chmod the *.jar files to include
the execution bit, then just do
       ./Application.jar


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
Commit	Line	Data
1da177e4 LT	1	Java(tm) Binary Kernel Support for Linux v1.03
	2	----------------------------------------------
	3
	4	Linux beats them ALL! While all other OS's are TALKING about direct
	5	support of Java Binaries in the OS, Linux is doing it!
	6
	7	You can execute Java applications and Java Applets just like any
	8	other program after you have done the following:
	9
	10	1) You MUST FIRST install the Java Developers Kit for Linux.
	11	The Java on Linux HOWTO gives the details on getting and
	12	installing this. This HOWTO can be found at:
	13
	14	ftp://sunsite.unc.edu/pub/Linux/docs/HOWTO/Java-HOWTO
	15
	16	You should also set up a reasonable CLASSPATH environment
	17	variable to use Java applications that make use of any
	18	nonstandard classes (not included in the same directory
	19	as the application itself).
	20
	21	2) You have to compile BINFMT_MISC either as a module or into
	22	the kernel (CONFIG_BINFMT_MISC) and set it up properly.
	23	If you choose to compile it as a module, you will have
	24	to insert it manually with modprobe/insmod, as kmod
84eb8d06	25	cannot easily be supported with binfmt_misc.
1da177e4 LT	26	Read the file 'binfmt_misc.txt' in this directory to know
	27	more about the configuration process.
	28
	29	3) Add the following configuration items to binfmt_misc
	30	(you should really have read binfmt_misc.txt now):
	31	support for Java applications:
	32	':Java:M::\xca\xfe\xba\xbe::/usr/local/bin/javawrapper:'
	33	support for executable Jar files:
	34	':ExecutableJAR:E::jar::/usr/local/bin/jarwrapper:'
	35	support for Java Applets:
	36	':Applet:E::html::/usr/bin/appletviewer:'
	37	or the following, if you want to be more selective:
	38	':Applet:M::<!--applet::/usr/bin/appletviewer:'
	39
	40	Of cause you have to fix the path names. Given path/file names in this
	41	document match the Debian 2.1 system. (i.e. jdk installed in /usr,
	42	custom wrappers from this document in /usr/local)
	43
	44	Note, that for the more selective applet support you have to modify
	45	existing html-files to contain <!--applet--> in the first line
	46	('<' has to be the first character!) to let this work!
	47
	48	For the compiled Java programs you need a wrapper script like the
	49	following (this is because Java is broken in case of the filename
	50	handling), again fix the path names, both in the script and in the
	51	above given configuration string.
	52
	53	You, too, need the little program after the script. Compile like
	54	gcc -O2 -o javaclassname javaclassname.c
	55	and stick it to /usr/local/bin.
	56
	57	Both the javawrapper shellscript and the javaclassname program
	58	were supplied by Colin J. Watson <cjw44@cam.ac.uk>.
	59
	60	====================== Cut here ===================
	61	#!/bin/bash
	62	# /usr/local/bin/javawrapper - the wrapper for binfmt_misc/java
	63
	64	if [ -z "$1" ]; then
	65	exec 1>&2
	66	echo Usage: $0 class-file
	67	exit 1
	68	fi
	69
	70	CLASS=$1
	71	FQCLASS=`/usr/local/bin/javaclassname $1`
	72	FQCLASSN=`echo $FQCLASS \| sed -e 's/^.\.\([^.]\)$/\1/'`
	73	FQCLASSP=`echo $FQCLASS \| sed -e 's-\.-/-g' -e 's-^[^/]$--' -e 's-/[^/]$--'`
	74
	75	# for example:
	76	# CLASS=Test.class
	77	# FQCLASS=foo.bar.Test
	78	# FQCLASSN=Test
	79	# FQCLASSP=foo/bar
	80
	81	unset CLASSBASE
	82
	83	declare -i LINKLEVEL=0
	84
	85	while :; do
	86	if [ "`basename $CLASS .class`" == "$FQCLASSN" ]; then
	87	# See if this directory works straight off
	88	cd -L `dirname $CLASS`
	89	CLASSDIR=$PWD
90	cd $OLDPWD
91	if echo $CLASSDIR \| grep -q "$FQCLASSP$"; then
92	CLASSBASE=`echo $CLASSDIR \| sed -e "s.$FQCLASSP$.."`
93	break;
94	fi
95	# Try dereferencing the directory name
96	cd -P `dirname $CLASS`
97	CLASSDIR=$PWD
98	cd $OLDPWD
99	if echo $CLASSDIR \| grep -q "$FQCLASSP$"; then
100	CLASSBASE=`echo $CLASSDIR \| sed -e "s.$FQCLASSP$.."`
101	break;
102	fi
103	# If no other possible filename exists
104	if [ ! -L $CLASS ]; then
105	exec 1>&2
106	echo $0:
107	echo " $CLASS should be in a" \
108	"directory tree called $FQCLASSP"
109	exit 1
110	fi
111	fi
112	if [ ! -L $CLASS ]; then break; fi
113	# Go down one more level of symbolic links
114	let LINKLEVEL+=1
115	if [ $LINKLEVEL -gt 5 ]; then
116	exec 1>&2
117	echo $0:
118	echo " Too many symbolic links encountered"
119	exit 1
120	fi
121	CLASS=`ls --color=no -l $CLASS \| sed -e 's/^.* \([^ ]*\)$/\1/'`
122	done
123
124	if [ -z "$CLASSBASE" ]; then
125	if [ -z "$FQCLASSP" ]; then
126	GOODNAME=$FQCLASSN.class
127	else
128	GOODNAME=$FQCLASSP/$FQCLASSN.class
129	fi
130	exec 1>&2
131	echo $0:
132	echo " $FQCLASS should be in a file called $GOODNAME"
133	exit 1
134	fi
135
136	if ! echo $CLASSPATH \| grep -q "^\(.:\)$CLASSBASE\(:.\)"; then
137	# class is not in CLASSPATH, so prepend dir of class to CLASSPATH
138	if [ -z "${CLASSPATH}" ] ; then
139	export CLASSPATH=$CLASSBASE
140	else
141	export CLASSPATH=$CLASSBASE:$CLASSPATH
142	fi
143	fi
144
145	shift
146	/usr/bin/java $FQCLASS "$@"
147	====================== Cut here ===================
148
149
150	====================== Cut here ===================
151	/* javaclassname.c
152	*
153	* Extracts the class name from a Java class file; intended for use in a Java
154	* wrapper of the type supported by the binfmt_misc option in the Linux kernel.
155	*
156	* Copyright (C) 1999 Colin J. Watson <cjw44@cam.ac.uk>.
157	*
158	* This program is free software; you can redistribute it and/or modify
159	* it under the terms of the GNU General Public License as published by
160	* the Free Software Foundation; either version 2 of the License, or
161	* (at your option) any later version.
162	*
163	* This program is distributed in the hope that it will be useful,
164	* but WITHOUT ANY WARRANTY; without even the implied warranty of
165	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
166	* GNU General Public License for more details.
167	*
168	* You should have received a copy of the GNU General Public License
169	* along with this program; if not, write to the Free Software
170	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
171	*/
172
173	#include <stdlib.h>
174	#include <stdio.h>
175	#include <stdarg.h>
176	#include <sys/types.h>
177
178	/* From Sun's Java VM Specification, as tag entries in the constant pool. */
179
180	#define CP_UTF8 1
181	#define CP_INTEGER 3
182	#define CP_FLOAT 4
183	#define CP_LONG 5
184	#define CP_DOUBLE 6
185	#define CP_CLASS 7
186	#define CP_STRING 8
187	#define CP_FIELDREF 9
188	#define CP_METHODREF 10
189	#define CP_INTERFACEMETHODREF 11
190	#define CP_NAMEANDTYPE 12
191
192	/* Define some commonly used error messages */
193
194	#define seek_error() error("%s: Cannot seek\n", program)
195	#define corrupt_error() error("%s: Class file corrupt\n", program)
196	#define eof_error() error("%s: Unexpected end of file\n", program)
197	#define utf8_error() error("%s: Only ASCII 1-255 supported\n", program);
198
199	char *program;
200
201	long *pool;
202
203	u_int8_t read_8(FILE *classfile);
204	u_int16_t read_16(FILE *classfile);
205	void skip_constant(FILE classfile, u_int16_t cur);
206	void error(const char *format, ...);
207	int main(int argc, char **argv);
208
209	/* Reads in an unsigned 8-bit integer. */
210	u_int8_t read_8(FILE *classfile)
211	{
212	int b = fgetc(classfile);
213	if(b == EOF)
214	eof_error();
215	return (u_int8_t)b;
216	}
217
218	/* Reads in an unsigned 16-bit integer. */
219	u_int16_t read_16(FILE *classfile)
220	{
221	int b1, b2;
222	b1 = fgetc(classfile);
223	if(b1 == EOF)
224	eof_error();
225	b2 = fgetc(classfile);
226	if(b2 == EOF)
227	eof_error();
228	return (u_int16_t)((b1 << 8) \| b2);
229	}
230
231	/* Reads in a value from the constant pool. */
232	void skip_constant(FILE classfile, u_int16_t cur)
233	{
234	u_int16_t len;
235	int seekerr = 1;
236	pool[*cur] = ftell(classfile);
237	switch(read_8(classfile))
238	{
239	case CP_UTF8:
240	len = read_16(classfile);
241	seekerr = fseek(classfile, len, SEEK_CUR);
242	break;
243	case CP_CLASS:
244	case CP_STRING:
245	seekerr = fseek(classfile, 2, SEEK_CUR);
246	break;
247	case CP_INTEGER:
248	case CP_FLOAT:
249	case CP_FIELDREF:
250	case CP_METHODREF:
251	case CP_INTERFACEMETHODREF:
252	case CP_NAMEANDTYPE:
253	seekerr = fseek(classfile, 4, SEEK_CUR);
254	break;
255	case CP_LONG:
256	case CP_DOUBLE:
257	seekerr = fseek(classfile, 8, SEEK_CUR);
258	++(*cur);
259	break;
260	default:
261	corrupt_error();
262	}
263	if(seekerr)
264	seek_error();
265	}
266
267	void error(const char *format, ...)
268	{
269	va_list ap;
270	va_start(ap, format);
271	vfprintf(stderr, format, ap);
272	va_end(ap);
273	exit(1);
274	}
275
276	int main(int argc, char **argv)
277	{
278	FILE *classfile;
279	u_int16_t cp_count, i, this_class, classinfo_ptr;
280	u_int8_t length;
281
282	program = argv[0];
283
284	if(!argv[1])
285	error("%s: Missing input file\n", program);
286	classfile = fopen(argv[1], "rb");
287	if(!classfile)
288	error("%s: Error opening %s\n", program, argv[1]);
289
290	if(fseek(classfile, 8, SEEK_SET)) /* skip magic and version numbers */
291	seek_error();
292	cp_count = read_16(classfile);
293	pool = calloc(cp_count, sizeof(long));
294	if(!pool)
295	error("%s: Out of memory for constant pool\n", program);
296
297	for(i = 1; i < cp_count; ++i)
298	skip_constant(classfile, &i);
299	if(fseek(classfile, 2, SEEK_CUR)) /* skip access flags */
300	seek_error();
301
302	this_class = read_16(classfile);
303	if(this_class < 1 \|\| this_class >= cp_count)
304	corrupt_error();
305	if(!pool[this_class] \|\| pool[this_class] == -1)
306	corrupt_error();
307	if(fseek(classfile, pool[this_class] + 1, SEEK_SET))
308	seek_error();
309
310	classinfo_ptr = read_16(classfile);
311	if(classinfo_ptr < 1 \|\| classinfo_ptr >= cp_count)
312	corrupt_error();
313	if(!pool[classinfo_ptr] \|\| pool[classinfo_ptr] == -1)
314	corrupt_error();
315	if(fseek(classfile, pool[classinfo_ptr] + 1, SEEK_SET))
316	seek_error();
317
318	length = read_16(classfile);
319	for(i = 0; i < length; ++i)
320	{
321	u_int8_t x = read_8(classfile);
322	if((x & 0x80) \|\| !x)
323	{
324	if((x & 0xE0) == 0xC0)
325	{
326	u_int8_t y = read_8(classfile);
327	if((y & 0xC0) == 0x80)
328	{
329	int c = ((x & 0x1f) << 6) + (y & 0x3f);
330	if(c) putchar(c);
331	else utf8_error();
332	}
333	else utf8_error();
334	}
335	else utf8_error();
336	}
337	else if(x == '/') putchar('.');
338	else putchar(x);
339	}
340	putchar('\n');
341	free(pool);
342	fclose(classfile);
343	return 0;
344	}
345	====================== Cut here ===================
346
347
348	====================== Cut here ===================
349	#!/bin/bash
350	# /usr/local/java/bin/jarwrapper - the wrapper for binfmt_misc/jar
351
352	java -jar $1
353	====================== Cut here ===================
354
355
356	Now simply chmod +x the .class, .jar and/or .html files you want to execute.
357	To add a Java program to your path best put a symbolic link to the main
358	.class file into /usr/bin (or another place you like) omitting the .class
359	extension. The directory containing the original .class file will be
360	added to your CLASSPATH during execution.
361
362
363	To test your new setup, enter in the following simple Java app, and name
364	it "HelloWorld.java":
365
366	class HelloWorld {
367	public static void main(String args[]) {
368	System.out.println("Hello World!");
369	}
370	}
371
372	Now compile the application with:
373	javac HelloWorld.java
374
375	Set the executable permissions of the binary file, with:
376	chmod 755 HelloWorld.class
377
378	And then execute it:
379	./HelloWorld.class
380
381
382	To execute Java Jar files, simple chmod the *.jar files to include
383	the execution bit, then just do
384	./Application.jar
385
386
387	To execute Java Applets, simple chmod the *.html files to include
388	the execution bit, then just do
389	./Applet.html
390
391
392	originally by Brian A. Lantz, brian@lantz.com
393