MKS LEX & YACC Release Notes
Release 3.3.1

MKS Software Inc.
12450 Fair Lakes Circle, Suite 400
Fairfax VA 22033 USA
Support: +1-703-803-7660

March 2001


New in MKS LEX & YACC 3.3.1
New in MKS LEX & YACC 3.3
Platform Support
Uninstalling MKS LEX & YACC
Using MKS LEX & YACC with MKS Toolkit
Customer Support
Additional MKS LEX & YACC Resources
Problems Fixed in Release 3.3.1

New in MKS LEX & YACC Release 3.3.1

Changes in MKS LEX & YACC Release 3.3.1 include:

For more information on these changes, see Problems Fixed in Release 3.3.1 below.

New in MKS LEX & YACC Release 3.3

MKS LEX & YACC Release 3.3 features the following changes from previous releases:


Documentation for MKS LEX & YACC is divided into two parts:

To properly read the online HTML Help files, you must have Microsoft Internet Explorer 4.0 or later installed on your system. It does not need to be your default browser.

The HTML Help files provide the following documentation:

You can access the online reference pages for the command line utilities provided in MKS LEX & YACC either through the Help button of the Microsoft Visual Studio add-in or by using the command line man utility to view the ASCII reference pages. To access a command's reference page, type

     man cmd_name

For example, to get the reference page for the yacc command, you would type

     man yacc

To access a miscellaneous information page, type

     man 5 page_name

For example, to see the miscellaneous information page for yacc, you would type

man 5 yacc

Platform Support

MKS LEX & YACC 3.3.1 supports the following platforms:

Note the Microsoft Visual Studio add-in does not work for versions of Visual Studio before 6.0.

Uninstalling MKS LEX & YACC

To uninstall MKS LEX & YACC:

  1. Run Add/Remove Programs from the control panel.

  2. Remove MKS LEX & YACC.

There is a known problem uninstalling MKS LEX & YACC on Windows 2000 using the control panel's Add/Remove Programs application. The uninstall information is not deleted and the Start menu is not cleaned up. All other executable and support files are removed. Attempting to run the Lex and Yacc Configuration item from the Start menu or to uninstall MKS LEX & YACC again from the control panel results in a "Fatal error during installation" message being displayed. To completely uninstall MKS LEX & YACC on Windows 2000, run setup.exe from the original distribution media and select Remove from the opening screen.

Using MKS LEX & YACC with MKS Toolkit

When you have both MKS LEX & YACC and MKS Toolkit (Version 7.0+) installed on your system, several issues arise because of the inclusion of the SCO versions of the lex and yacc utilities in MKS Toolkit for Enterprise Developers.

Getting the Right Reference Pages

On a system with both MKS LEX & YACC and MKS Toolkit, typing one of the following:

man lex
man yacc

displays the plain text version of the reference page for SCO lex or SCO yacc, respectively.

To display the plain text reference pages for the MKS lex and yacc utilities, you must type one of these commands:

man mks_lex
man mks_yacc

Also, the HTML Help versions of the MKS LEX & YACC reference pages are not viewable with the MKS Toolkit man -h command. You can view them as described earlier or by typing


at the Windows NT/2000 command prompt or


at the MKS KornShell command prompt.

Getting the Right Executable

On a system with both MKS LEX & YACC and MKS Toolkit for Enterprise Developers installed, you should ensure root_dir/mksnt comes before root_dir/bin (where root_dir is the directory in which) in your Path environment variable value. This ensures that you are running the lex and yacc utilities from MKS LEX & YACC as opposed to the SCO lex and yacc utilities from MKS Toolkit. To access the SCO versions, you can type one of the following at the Windows NT/2000 command prompt:


or one of these at the MKS KornShell command prompt:


Customer Support

To receive support for your MKS Software product, you must buy a Preferred Customer Support (PCS) contract for that product. Some MKS Software products come bundled with PCS. For others, PCS is optional. PCS is renewable annually for a small fee and entitles you to unlimited customer support, patches, bug fixes, and all product upgrades for the duration of the contract. In any given 12-month period, MKS Software typically releases one minor upgrade (maintenance), one major upgrade (new features), and several patches, none of which you will want to miss.

In addition, customers with PCS may elect to receive periodic mailings from our customer support organization. These mailings—geared at end users—outline new features, give tips for using features, discuss how to solve common problems, and provide other frequently requested information. Moreover, as MKS Software moves more of its internal support information onto the support web site, only those customers with PCS will be able to access this controlled information, that will include instant status about reported issues, a searchable database of frequently asked questions, and much more detailed self-help information.

If you are a new customer or you have never activated your PCS account, you must register with our customer support organization. Registration—mandatory before you can receive support—is simple. The easiest way to register is by filling out the registration form during product installation, or you may do so at any time over the web at And please be assured that this information is used for no other purpose than to provide support to you. Your personal information will not be given to anyone else.

Without PCS, you will not be entitled to any support, patches, bug fixes, upgrades, mailings, or self-help information. If you do not have PCS, all of our sales channels offer MKS Software products with bundled PCS for your convenience. If you already have product, but need PCS, you may purchase a PCS contract by contacting MKS Software directly at 800-637-8034 or +1-703-803-3343.

With PCS, you can request customer support by contacting us using one of the means listed below and in your request, include the name and version number of the product that you are using, your serial number, and the operating system and version/patch level that you are using. Contact MKS Software customer support at:

  • Web:
    Telephone: +1-703-803-7660 (9:00am to 7:00pm Eastern, Mon-Fri)
    Fax: +1-703-803-3344

  • Additional MKS LEX & YACC Resources

    Problems Fixed in Release 3.3.1

    The following table documents issues that were fixed in this release:


    SR 9393 Not all prefix substitutions are being made with yacc -p in C++
    SR 13418 segmentation violation on large grammar
    SR 18073 yacc blows up on shift/reduce conflicts if the -v switch is on
    SR 18595 lex generates invalid #line directives
    SR 18651 yacc segmentation faults on user's huge grammar