Command Line Versus Command Line

Microsoft copied its idea of the command line from Gary Kildall’s
CP/M, which in turn copied it from the DEC operating systems of the
1970s. This is just a simple string/array of characters. Implicit in
these systems is the idea that one program cannot directly execute
another; it has to go through a “command interpreter”, which has to be
given a “command” to “interpret”.

Compare the Unix concept of a command line: it is not a “line” at all, but
an array of strings. One program can directly execute another without
having to go through a shell: it can construct and pass this argument
array without having to worry about “special” characters that might be
(mis)interpreted by some CLI/shell intermediary -- unless you choose to go
through such an intermediary.

Those old DEC systems tended to have more complex syntax for their
commands than what is supported by your typical *nix command-line
program. But then, the sheer wealth of *nix command-line tools,
compared to what is available on Microsoft DOS/Windows/NT/PowerShell
and indeed all the proprietary OSes put together, shows that the
*nix-style command line is far more versatile. In *nix, most of the
sophistication is delegated to the shell language that is used to
invoke these programs, while the programs themselves can usually parse
their arguments using a fairly modest amount of code, with little or
no need for some more sophisticated command-line-handling library.

Just to reinforce the direction that Microsoft took, Dave Cutler,
the brains behind Windows NT, also came from DEC, where he was
part of a nest of Unix-haters.

So Microsoft’s recent rediscovery that “the command line is cool”
remains hampered by this brain-dead underlying architecture. The
requirement that most if not all process creation has to be mediated
by some command-line “shell” makes it quite clumsy to emulate the kind
of multi-process pipelines that are all in a day’s work on a Linux or
other *nix system. It also leads to some interesting security
vulnerabilities.