[Info-vax] Local Versus Global Command Options

[Mark Berryman]

On 2/16/25 5:43 PM, Lawrence D'Oliveiro wrote:
> On Sun, 16 Feb 2025 15:52:23 -0700, Mark Berryman wrote:
> 
>> On *nix systems, the shell parses the command line into an array of
>> strings using unquoted spaces as the separator which is then passed to
>> the created process.
> 
> If you don’t go through a shell, then you pass an array of already-
> separated words and you don’t have to worry about shell specials.
> 
>> On VMS, the crtl does the same parsing which means the program still
>> sees an array of strings the same as on a *nix system.
> 
> Consider what happens: if you pass unquoted text to program X, DCL
> converts it to uppercase, and I think also normalizes multiple spaces to a
> single space. If you don’t want the text to be uppercased or space-
> normalized, you put it in pairs of double quotes. But then these double
> quotes also get passed as part of the command line. So the receiving
> program has to do some non-trivial parsing just to get simple literal text
> via the command line.

So, so, so very wrong.  You are *way* behind the times.

I *never* have to quote arguments when using programs that still use 
*nix syntax on VMS.  My arguments' case is never changed.

Here is the entry point to any C program on VMS:

  int main (int argc, char *argv[], char *envp[]);

See?  Argument passing works the same on VMS as it does on *nix, as 
described above.

Let's see, what's a good example?  Ah, here's one:

$ gs -q -P- -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -sstdout=%stderr 
-sOutputFile=<something>.pdf <something>.ps

Again, see?  No quoting.  No case conversion.  Ghostscript sees the 
command exactly as I typed it and I typed it exactly as I would on a 
*nix system.

> 
> So now, how do you invoke program X directly from your own program Y,
> without going through DCL? For consistency, you have to mimic all the same
> misbehaviour of DCL to get the command line in the right format. If you
> don’t want to do that, then you need some option to tell program X to
> bypass all that special processing, and just accept the command line as
> is. So it needs to distinguish between two ways of being invoked: directly
> or via DCL!

Wrong again. There are a number of ways to invoke a program without 
going through DCL.  Since you seem to be a Linux fan, look up the 
various exec functions for starters.  (Note, there are other ways).

> 
>> If I choose to use DCL, DCL does all of the parsing for me and the
>> nature of the command-line is irrelevant.
> 
> If you don’t use DCL, then how do you invoke a program that expects DCL to
> parse its command line for it? What happens to all of Arne’s lovingly-
> crafted .CLD files?

You apparently know as little about VMS as you do programming in 
general.  The Docs are online.  Go read them.  They will answer your 
questions.

> 
>> Programs on DEC OSes can invoke other programs directly and
>> have been able to at least since the days of the PDP-11 ...
> 
> Yes, and there have been quite a few pitfalls with that, as I mentioned
> above. Windows suffers from the same drawback, and this has even led to
> security holes with Windows programs.

Hmmm, first you tout that invoking programs directly eliminates pitfalls 
then you claim that doing so causes them.  So, which is it?

Mark Berryman