This question is more about DOS in general than specifically about FreeDOS. But, there are enough experienced and creative users around FreeDOS that someone may be able to help me come up with a solution.
I have a large set of DOS environments I use for testing. Basically, I have a bunch of different versions of DOS that I can boot to (MS-DOS, PC-DOS, FreeDOS, DR-DOS, from versions 3.0 to the latest of each). DOS versions 1 & 2 were so lackluster that I don't bother even testing with them. I have a copy of the commercial program called System Commander which allows me to install and boot all these different versions of DOS from a single partition on a hard drive. I know there are other ways to accomplish the same feat, but I bought a copy of System Commander a long time ago so that is what I use. I have all these DOS's installed on a Virtual hard drive so that I can run them in different Virtual Machines with different types of CPUs (from the lowly 8088 all the way up to modern CPUs). Again, this is a test environment so that as I write programs I can verify they work whenever and wherever they're supposed to. On the Virtual hard drive part of what System Commander does as you boot is "restore" the hidden boot files (IO.SYS & MSDOS.SYS for MS-DOS, IBMBIO.COM & IBMDOS.COM for PC- and DR-DOS, or KERNEL.SYS for FreeDOS), along with the COMMAND.COM, CONFIG.SYS, and AUTOEXEC.BAT files so that the virtual machine boots with the correct test environment. The problem is that the older versions of DOS don't work exactly like the newer versions, particularly when it comes to batch files. For example, prior to DOS version 3.3 you couldn't CALL one batch file from another, and also prior to DOS version 3.3 you couldn't use the @ symbol at the beginning of a line in a batch file to hide the output of the line (sort of similar to what happens with the ECHO OFF you normally put at the beginning of batch files but the @ symbol only works for a single line instead of the entire batch file like ECHO OFF does). So, I have a relatively short AUTOEXEC.BAT file set up for each OS I boot, which is unique to each OS. The main thing this small AUTOEXEC.BAT does is set up some environment variables to identify the OS that booted which can be used later in other batch files. At the end of the "simple" AUTOEXEC.BAT file, I then jump to a "master" AUTOEXEC.BAT file that is common to all the booted DOS's. Because each version of DOS is a little different, the "master" AUTOEXEC.BAT file needs to do some "IF-THEN" scenarios based on which version of DOS is running. I want the overall environment to be pretty much the same (as much as I can, anyway) no matter which DOS is running. Having a "master" AUTOEXEC.BAT file lets me make most of my changes in one common place instead of needing to do the same thing a bunch of different times for each DOS version. One problem I haven't figured out how to handle correctly is the ECHO OFF vs @ECHO OFF issue. In older versions of MS- and PC-DOS (prior to version 3.3), and all versions of DR-DOS, the "@ECHO OFF" command does not work at the beginning of batch files. You need to use a simple "ECHO OFF" instead. If they see an "@ECHO OFF" they display an "unknown command" error (it tries to find an executable files called "@ECHO"). I'm trying to figure out a way for all the "common" batch files (all batch files other than the small AUTOEXEC.BAT file) to detect whether they can put the "@" at the beginning of the line or not to keep the screen from getting unnecessarily cluttered and confusing. I cannot figure out a way to do this. I'll go through some of the things I've tried (to no avail -- the all put "unnecessary stuff on the screen). I've tried creating an ECHO environment variable. With older versions of DOS: SET ECHO=ECHO OFF and with newer versions of DOS: SET ECHO=@ECHO OFF then at the beginning of all batch files I put a: %ECHO% That works with older versions of DOS but not newer versions. With newer versions, it sees the "%" at the beginning of the line instead of the "@" and looks for an executable file called "@ECHO" instead of seeing the "@" as the "hide this line" character. Another option would be to create an actual @ECHO.BAT file and always put an @ECHO as the first line of all batch files, but that won't work either. The "@ECHO OFF" line will show up on the screen (which is what I'm trying to avoid), and in addition you must CALL the @ECHO.BAT file instead of just running it. And you can't use CALL in older version of DOS. I've also thought of trying to use aliases/macros with ANSI or DOSKEY (or clones of those) but that won't work either. ANSI will only create aliases/macros for single characters (not entire words like ECHO or @ECHO), and DOSKEY (or a clone) macros only work at the command-line and not in batch files. Something like aliases in FreeDOS or 4DOS might work (I'm not sure), but that defeats the purpose of the testing which requires "native" DOS versions. I'm stumped. Right new it seems as if my only viable option is to always use "ECHO OFF" instead of "@ECHO OFF" and just live with the cluttered screens in later versions of DOS even though they could be avoided if I wasn't trying to boot so many old DOS's on the same machine. I realize this is a minor issues in the grand scheme of things, but would still like to figure out a solution if there is one. It's also interesting when you experiment with the different DOS's to see what kinds of compatibility issues there are. I've found DR-DOS isn't nearly as compatible with MS-DOS as it's supposed to be. I've also heard/read that MS-DOS and PC-DOS were for all practical purposes exactly the same up through version 6.1, but I've found that not to be true either. From a compatibility perspective, FreeDOS is actually pretty good (not perfect, but definitely better than DR-DOS). Anyway, any other ideas on how to resolve the ECHO/@ECHO issue? _______________________________________________ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
