[Info-vax] Command Line Versus Command Line

[Arne Vajhøj]

On 5/23/2024 12:02 PM, Michael S wrote:
> On Thu, 23 May 2024 09:28:16 -0400
> Arne Vajhøj <arne at vajhoej.dk> wrote:
>> On 5/23/2024 6:19 AM, Scott Dorsey wrote:
>>> Lawrence D'Oliveiro  <ldo at nz.invalid> wrote:
>>>> And just to add to the fun, CP/M, MS-DOS and then Windows NT all
>>>> copied the basic DEC-style command line architecture, while
>>>> neglecting the crucial part of a built-in command parser to handle
>>>> more sophisticated syntax. So Microsoft’s recent rediscovery that
>>>> “the command line is cool” remains hampered by this brain-dead
>>>> underlying architecture.
>>>
>>> To give them credit, Microsoft finally realized that command.com was
>>> hopeless and started from first principles with Powershell.
>>> Powershell is easily as good as anything DEC had in 1974 and as
>>> such is a huge advance for the desktop.
>>
>> Just so that everyone know the history:
>>
>> command.com - 1980
>> cmd.exe - 1987 (backwards compatible with command.com, but
>> significantly extended functionality, often via obscure syntax though)
> 
> Thanks.
> Until reading your post I didn't realize that cmd.exe existed before Nt
> 3.1 (1993).
> Personally I often feel that cmd.exe is an improvement on it's
> successor.
>> Windows Script Host / VBScript - 1995 (not interactive, scripts only,
>> but very powerful via WMI)
>> PowerShell - 2006
>>
>> Not super new.

> BTW, I tried to figure out what "command line architecture" Lawrence is
> talking about, but didn't quite succeed.

Neither did I.

> As far as Win32 CreateProcess() function is concerned, command line
> is just a string. If caller omits applicationName parameter then
> system does small amount of parsing to find application name in command
> line. But when caller provides applicationName parameter, which is a
> most logical thing to do in any non-interactive/non-shell scenario,
> then OS does not care at all about content of command line. In both
> cases OS does not modify command line and passes it to child
> process as is.

The concept is pretty common.

VMS LIB$SPAWN and C system also use full command line.

> So, the only difference between *nix and Windows is array of
> ASCIIZ strings (today, of UTF8 strings) vs single, possibly very long,
> null-terminated ASCII or UTF16 string.

In most practical usages it does not matter at all.

But it can matter if one needs to construct a single command
line from multiple arguments and those arguments contain
spaces or shell operators.

Example:
   https://nvd.nist.gov/vuln/detail/CVE-2024-24576

Arne