[TUHS] Dash options

Andrew Warkentin andreww591 at gmail.com
Tue Nov 28 16:49:54 AEST 2017


On 11/27/17, Dave Horsfall <dave at horsfall.org> wrote:
> On Mon, 27 Nov 2017, Jon Steinhart wrote:
>
>> Does anybody know the history of dash options?  Were they a UNIX thing
>> or did UNIX borrow them from something earlier?
>
> An equivalent question would be why "/" was chosen as the directory
> separator, as it was commonly used for flags.
>

Multics had dash options, so that's presumably where Unix got them
from. I believe slash options were mostly a DEC thing that DOS and its
successors borrowed (I think they originated in TOPS-10). I don't
think there was any widespread syntax for options when the first
versions of Unix were written, and slash and dash options weren't the
only syntaxes used (e.g. JCL-ish key=value options were used on some
systems). The thing that I wonder about was why ">" wasn't used as the
directory separator when paths were added to Unix, since that's what
Multics used.


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