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Part II: Installing JFlex and CUP - Specific Instructions

This is the second of a series whose first article appeared in the April, 1999 issue of Linux Gazette. [see:  Compiler Construction Tools, Part I ]. The traditional example, the calculator, is provided in Part III, which is intended as a companion to this part and also appears in this issue.

0.0 Background

The JFlex and CUP software packages come with installation instructions. These are well written and straightforward. Nevertheless this document was written to give a very specific installation scenario. In the author's experience, this specificity can be useful to certain new users who find the generality and flexibility of less specific installation instructions somewhat difficult upon first exposure. The downside is that this specificity takes away flexibility.

These instructions are intended for use with a Linux box, with bash as the default shell and with the tcsh also installed, but not as default. It is assumed that the user has a version of jdk (Java Development Kit), or some equivalent, installed already. If not, you can find such at www.blackdown.org/.    In the system used by the author, the compressed tarball of jdk1.1.5-v5-glibc.tar.gz from blackdown was downloaded into /usr/lib and exploded there.

The author would appreciate corrections and constructive suggestions. He can be contacted at:  rsevenich@ewu.edu

1.0 System Preparation

Note that the specific choices made in this section are arbitrary. For starters, it is assumed that you have logged into your home directory, say, /home/jsmith. All paths will be relative to that position within the file hierarchy. Make new directories as follows:

> mkdir javatools
> mkdir javatools/CUP

Next revise your .bash_profile and .bashrc files to have the needed java CLASSPATH etc. Here are some example lines:

JAVB=/usr/lib/jdk1.1
JAVT=/home/jsmith/javatools
CLASSPATH=./:$JAVB/lib/classes.zip:$JAVT/JFlex/lib/JFlex.jar:$JAVT/CUP
PATH=$PATH:$JAVB/bin:$JAVT/JFlex/bin
export PATH CLASSPATH

Note: The directory /usr/lib/jdk1.1 is meant to denote the site of the java files exploded from the blackdown tarball. In the author's case it was a symbolic link to /usr/lib/jdk1.1.5v5-980311/.

For these changes to take effect you must log out and log back in.

2.0 JFlex

2.1 Obtaining JFlex

JFlex is available from  www.informatik.tu-muenchen.de/~kleing/jflex/index.html#Download
in a tar.gz format. At this writing the file name was 'jflex-1.2.tar.gz'. This tarball includes an extensive manual with its own installation instructions.

2.2 A Specific Installation Scenario

• Download the tarball,  jflex-1.2.tar.gz, into directory javatools/
• from within the javatools/ directory explode the tarball at the command line by typing 'tar xvfz jflex-1.2.tar.gz'

• change JFLEX_HOME to be your equivalent of 'JFLEX_HOME=/home/jsmith/javatools/JFlex'
• change JAVA_HOME to be your equivalent of 'JAVA_HOME=/usr/lib/jdk1.1'

2.3 Testing the Installation

• Change directory to javatools/JFlex/examples/standalone (e.g. 'cd /home/jsmith/javatools/JFlex/examples/standalone/')
• Follow the instructions in the README file found in that directory, which should result in this screen output:

          This is a sample input file for the
          standalone example scanner.

           Have a nice day!
 

3.0 CUP

3.1 Obtaining CUP

CUP is available from www.cs.princeton.edu/~appel/modern/java/.  There you'll find the needed source code (compressed tarball) and a user manual. The manual can be downloaded in html to provide an on-line manual or in a form (e.g. postscript) suitable for printing. The next section deals with downloading the source file.
Note: The above website also contains an alternative to JFlex, called JLex.

3.2 A Specific Installation Scenario for CUP with test

• Download the compressed tarball into directory javatools/CUP
• Change to that directory (e.g. cd /home/jsmith/javatools/CUP)
• Explode the tarball
• Run the installation/testing file by typing at the command line './INSTALL' .Note that install is a script to be executed by csh, or its equivalent, tcsh. So tcsh should be available.

4.0 What Next?

The manuals downloaded with JFlex and CUP provide enough information so that users can get up and running.

Compiler Construction Tools Part I, April 1998