Communicator 3000 MPE/iX Release 6.0 (Platform Software Release C.60.00) (30216-90269)

Chapter 10 243
Technical Articles
Developer’s Kit for Java/iX
the one included with the OS is more recent. If you have installed any
version of Java on your system, you can determine the version by
typing the following at the POSIX shell prompt (or at a CI prompt if you
have set up the proper UDCs to allow Java to be accessed from the
Command Interpreter):
java -version
You can compare this to the version number in the readme file
(README.INSTALL.JAVA) after updating your MPE/iX system to 6.0. If
the 6.0 version is more recent, you can install it by typing the following
at the MPE CI prompt:
:STREAM JINSTJDK.INSTALL.JAVA
Shell or CI?
You can run Java from the MPE Command Interpreter or from the
POSIX shell. These are the differences between the two environments:
• The MPE Command Interpreter will launch Java programs faster,
because of the efficiency of MPE's CREATEPROCESS mechanism
compared to POSIX fork() and exec().
• The POSIX shell provides intelligent default values for several
environment variables, so the user does not, in most cases, have to
provide values.
Java uses six environment variables, and Java will be easier for you to
work with if you provide values for these via a command file or UDC (if
you use Java from the MPE CI) or a shell script or .profile (if you use
Java from the POSIX shell). These variables are:
• SYSNAME
• PATH (or HPPATH)
• CLASSPATH
• LD_LIBRARY_PATH
• THREADS_FLAG
• DISPLAY
Descriptions of these variables and their typical settings follow.
SYSNAME Variable
Example of setting SYSNAME from the shell:
shell/iX> export SYSNAME=hp3000
The SYSNAME variable is tested by some of the shell scripts provided
with Java. It does not need to be set in the MPE CI environment, since
the Java shell scripts are not used when running from the CI. It must
be set to hp3000, exactly as shown above.