'\" t
.\" @(#)jre.1 1.4 98/04/20 SMI;
.\" Copyright (c) 1996 Sun Microsystems, Inc.
.\" All Rights Reserved.
.TH jre 1 "24 June 1997" 
.SH NAME
jre \- Java runtime interpreter
.\" 
.\"  This document was created by saving an HTML file as text
.\"  from the JavaSoft web site:
.\" 
.\" http://www.javasoft.com:80/products/jdk/1.1/docs/tooldocs/solaris/index.html
.\" 
.\"  and adding appropriate troff macros.  Because the JavaSoft web site 
.\"  man pages can change without notice, it may be helpful to diff
.\"  files to identify changes other than new functionality. 
.\" 
.SH SYNOPSIS
.B jre 
[ 
.BI \-classpath " path(s)"
] [
.BI \-cp " path(s)"
] 
.if n .ti +5n
[
\f3\-D\fP\f2propertyName=newValue\fP
] [
.B \-help
] [
.BI \-mx  x
] 
.if t .ti +5n
[
.BI \-ms  x
] 
.if n .ti +5n
[
.B \-noasyncgc
] [
.B \-noclassgc
] [
.B -nojit
] [
.B \-noverify
] 
.if n .ti +5n
[
.BI \-oss x
] [
.BI \-ss  x
] 
.if t .ti +5n
[
.BR \-v " | " \-verbose
] [
.B \-verbosegc
] 
.if n .ti +5n
[
.B \-verify
] [
.B \-verifyremote
] 
.I classname 
<
.I args
>
.SH DESCRIPTION
.IX "Java runtime interpreter" "" "Java runtime interpreter \(em \fLjre\fP"
.IX "jre" "" "\fLjre\fP \(em Java runtime interpreter"
The 
.B jre 
command executes Java\(tm class files. The 
.I classname 
argument
is the name of the class to be executed. Any arguments to be
passed to the class must be placed after the classname on the
command line.
.SH OPTIONS
The following options are supported:
.TP 15
.BI \-classpath " path(s)"
Specifies the path or paths that 
.B jre 
uses to look up classes.
Overrides the default or the 
.SB CLASSPATH 
environment variable
if it is set. If more than one path is specified, they must
be separated by colons. Each path should end with the
directory containing the class files to be executed.
However, if a file to be executed is a zip or 
.BR jar (1)
file, the
path to that file must end with the file's name. Here is an
example of an argument for 
.B  \-classpath 
that specifies three
paths consisting of the current directory and two additional
paths:
.sp 1n
.RS 20
.B .:/home/xyz/classes:/usr/local/java/classes/MyClasses.jar
.RE
.sp 1n
.TP 15
.BI \-cp " path(s)"
Prepends the specified path or paths to the base classpath or
path given by the CLASSPATH environment variable. If more
than one path is specified, they must be separated by colons.
Each path should end with the directory containing the class
file(s) to be executed. However, if a file to be executed is
a zip or 
.BR jar (1)
file, the path to that file must end with the
file's name. Here is an example of an argument for 
.B  \-cp 
that specifies three paths consisting of the current directory and
two additional paths:
.sp 1n
.RS 20
.B .:/home/xyz/classes:/usr/local/java/classes/MyClasses.jar
.RE
.sp 1n
.TP 15
\f3\-D\fP\f2propertyName=newValue\fP
Defines a property value. 
.I propertyName 
is the name of the
property whose value you want to change and 
.I newValue 
is the
value to change it to. For example, this command line
.sp 1n
.RS 20
.B  example% jre -Dawt.button.color=green ...
.RE
.sp 1n
.RS 15
sets the value of the property 
.B awt.button.color 
to "green".
.B  jre
accepts any number of 
.B  \-D 
options on the command line.
.RE
.TP 15
.B \-help
Prints a usage message.
.br
.ne 7
.TP 15
.BI \-ms  x
Sets the startup size of the memory allocation pool (the
garbage collection heap) to 
.IR x . 
The default is 16 megabytes of
memory. The
.I x 
value must be greater than or equal to 1000 bytes.
.LP
.RS 15
By default, 
.I x 
is measured in bytes. You can specify 
.I x 
in
either kilobytes or megabytes by appending "k" for
kilobytes or "m" for megabytes.
.RE
.TP 15
.BI \-mx  x
Sets the maximum size of the memory allocation pool (the
garbage collection heap) to 
.IR x . 
The default is 1 megabyte of
memory. The
.I x 
value must be > 1000 bytes.
.LP
.RS 15
By default, 
.I x 
is measured in bytes. You can specify 
.I x 
in
either kilobytes or megabytes by appending "k" for
kilobytes or "m" for megabytes.
.RE
.TP 15
.B \-noasyncgc
Turns off asynchronous garbage collection. When activated, no
garbage collection takes place unless it is explicitly called
or the program runs out of memory. Normally garbage
collection runs as an asynchronous thread in parallel with
other threads.
.TP 15
.B 
-noclassgc
Turns off garbage collection of Java classes. By default, the
Java interpreter reclaims space for unused Java classes
during garbage collection.
.TP 15
.B 
-nojit
Specifies that any JIT compiler should be ignored and 
invokes the default Java interpreter.
.TP 15
.B \-noverify
Turns verification off.
.TP 15
.BI \-oss x
Each Java thread has two stacks: one for Java code and one
for C code. The 
.B  \-oss 
option sets the maximum stack size that
can be used by Java code in a thread to 
.IR x . 
Every thread that
is spawned during the execution of the program passed to 
.B jre
has 
.I x 
as its Java stack size. The default units for 
.I x 
are bytes. The value of 
.I x 
must be greater than or equal to 1000
bytes.
.LP
.RS 15
You can modify the meaning of 
.I x 
by appending either the
letter "k" for kilobytes or the letter "m" for megabytes. The
default stack size is 400 kilobytes (\f3\-oss400k\fP).
.RE
.br
.ne 9
.TP 15
.BI \-ss  x
Each Java thread has two stacks: one for Java code and one
for C code. The 
.B  \-ss 
option sets the maximum stack size that
can be used by C code in a thread to 
.IR x . 
Every thread 
spawned during the execution of the program passed to 
.B jre 
has
.I x 
as its C stack size. The default units for 
.I x 
are bytes. The
value of 
.I x 
must be greater than or equal to 1000 bytes.
.LP
.RS 15
You can modify the meaning of 
.I x 
by appending either the
letter "k" for kilobytes or "m" for megabytes. The
default stack size is 128 kilobytes (\f3\-ss128k\fP).
.RE
.TP 15
.BR \-v " | " \-verbose
Prints a message to 
.B stdout 
each time a class
file is loaded.
.br
.ne 5
.TP 15
.B \-verbosegc
Causes the garbage collector to print out messages whenever
it frees memory.
.TP 15
.B \-verify
Performs byte-code verification on the class file. Please note that
however, that 
.sp 1n
.RS 20
.B example% jre \-verify 
.RE
.sp 1n
.RS 15
does not perform a full
verification in all situations. Any code path that is not
actually executed by the interpreter is not verified and
therefore
cannot be relied upon to certify
class files unless all code paths in the class file are
actually run.
.RE
.TP 15
.B \-verifyremote
Runs the verifier on all code that is loaded into the system
using a classloader. This is the default for the
interpreter.
.SH ENVIRONMENT VARIABLES
.TP 15
.SB CLASSPATH
Use the 
.SB CLASSPATH 
environment variable to specify the
path to the class file or files that you want to execute.
.SB CLASSPATH 
consists of a colon-separated list of directories
that contain the class files to be executed. For example:
.br
.RS 20
.B .:/home/xyz/classes
.RE
.LP
.RS 15
If the file to be executed is a zip file or a 
.BR jar (1)
file, the
path should end with the file name. For example:
.br
.RE
.RS 20
.B .:/usr/local/java/classes/MyClasses.jar
.RE
.SH ATTRIBUTES
See
.BR attributes (5)
for a description of the following attributes:
.sp
.TS
box;
cbp-1 | cbp-1
l | l .
ATTRIBUTE TYPE	ATTRIBUTE VALUE
=
Availability	SUNWjvrt
.TE
.SH SEE ALSO
.BR jar (1),
.BR attributes (5)