[Info-vax] Local Versus Global Command Options

[Mark Berryman]

On 2/15/25 2:32 PM, Lawrence D'Oliveiro wrote:
> On Sat, 15 Feb 2025 12:22:59 -0700, Mark Berryman wrote:
> 
>> So, IMHO, DCL is superior in this regard.
> 
> Unfortunately, no. The fundamental problem with DEC OSes (and this
> includes Windows) is that the command line is passed to the program as a
> single string buffer. On *nix systems, it is passed as an array of
> strings.

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.

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.

If I choose to use DCL, DCL does all of the parsing for me and the 
nature of the command-line is irrelevant.

> 
> You should be familiar with the well-known problem of one program invoking
> another with a command that might include characters with special meanings
> to a shell. On a *nix system, there is a simple way to avoid those special
> meanings: the first program invokes the second program directly, without
> going through a shell.
> 
> Nowadays, there is even a simple library call to do this
> <https://manpages.debian.org/posix_spawn(3)>.
> 
> This is not so easy to do with a DEC-style command line.

Incorrect.  Programs on DEC OSes can invoke other programs directly and 
have been able to at least since the days of the PDP-11 (which somewhat 
predates the advent of posix_spawn).  The nature of the command-line is 
completely up to the program depending on what function is used to call 
the new program.

Mark Berryman