OS/2 Warp

The Workplace Shell (WPS) is the GUI that is installed by default to help us use OS/2 (an operating system). It may come as a shock to most people, but the WPS isn't the only shell you can run in OS/2; there are a number of freely available shells you can use instead.

Can I really?

You may find that your WPS uses too much memory, has too few (or even too many) functions, and generally drags the system down. If you have an older system, without a lot of RAM installed, you may be impressed by what an environment replacement can do. For a start, it can shave an huge 4M from your run-time environment. Before you get too excited, consider this: the more functions you demand from your alternate environment, the more RAM (and hard disk space for that matter) you can expect to take up. While a replacement environment may offer a smooth operating environment by being less demanding on your hardware, what you can do in your shell is likely to be limited. However, it may still be worth it for you.

Why should I?

Aside from performance issues, there are a number of reasons for using a different shell. If you have installed a maintenance partition (see APC March, page 144), a smaller GUI (or none at all) might just be the way to go. You don't need that power-hungry WPS taking up all of your system resources when all you want to do is unlock some files and change your CONFIG.SYS. You may not know it, but one of the most cut-down OS/2 environments is right in front of your nose: it's called CMD.EXE and it's on the OS/2 installation disk. Sure, it's text only, but it is still an operating environment.

If you administer several OS/2 workstations, a skeletal operating environment may be just the ticket for implementing security. If you replace the WPS with a less powerful command shell, you remove access to some of the more sensitive areas of a client machine. Some replacement shells, (FileBar for example), include security features that affect the shell and the applications themselves.

You really need to weigh up what in the WPS you can live without, and what a replacement can offer. You don't need a fully functional WPS if all you have is an OS/2 box that serves an Internet gateway. By reducing the system requirements for running OS/2 and your applications, you can use older hardware more effectively. Alternatively, you can lower the system requirements of a new workstation. OS/2 is a remarkably efficient server platform for low-specification machines.

How do I?

To start with, make sure that you haven't saved any documents in your WPS that aren't currently stored in a file somewhere. You won't get access to your OS2.INI and OS2SYS.INI files, so anything stored there won't be available to you. If you choose a text-based replacement environment, you won't have your files and utilities easily accessible though drop down folders, and some applications that require a GUI will simply not work.

There are four commands in your CONFIG.SYS file that tell OS/2 what type of shells you want to use and how to use them:

* PROTSHELL specifies which program you'd like to use as a session manager (the default is PMSHELL.EXE)

* RUNWORKPLACE specifies which shell you'd like to run as your workplace (the default is PMSHELL.EXE)

* OS2_SHELL specifies which program you wish to use as an OS/2 command-line interpreter (the default is CMD.EXE)

* SHELL specifies which program you wish to use as a DOS command line interpreter (the default is COMMAND.COM)

You may have noticed that OS/2's default PMSHELL.EXE is used as both the PROTSHELL and the RUNWORKPLACE. You will find that most environment replacements will only replace the RUNWORKPLACE, and still use PMSHELL.EXE as the PROTSHELL. There is a good reason for this: PMSHELL.EXE is quite fast and memory efficient as a session manager, but not as a WPS. If you wish, you can replace PMSHELL.EXE as your PROTSHELL, but the replacement shell must have session-management capabilities.

The OS2_SHELL and SHELL settings don't affect which WPS replacement you decide to boot (unless you choose to boot to a command shell), but they do allow you to further enhance your operating environment. Two of the most popular OS2_Shell replacements are YAOS (Yet Another OS/2 Shell) and 4OS2 (you may have used its DOS equivalent and shell replacement 4DOS). Both of these shells offer major feature enhancements over the standard CMD.EXE. In OS/2 this is always beneficial for those used to the command line, but if you elect to boot to one of these shells instead of the WPS, booting to a plain command line won't leave you pining for a more versatile environment.

Christopher Relf can be contacted via email at christopher.relf@mBox.com.au. For a complete list of APC OS/2 columns, see http://apcmag.com/