28 Nov
2017
28 Nov
'17
6:51 a.m.
Does anybody know the history of dash options? Were they
a UNIX thing or did UNIX borrow them from something earlier?
Jon
28 Nov
28 Nov
7:05 a.m.
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.
--
Dave Horsfall DTM (VK2KFU) "Those who don't understand security will
suffer."
7:49 a.m.
On 11/27/17, Dave Horsfall <dave(a)horsfall.org> wrote:
On Mon, 27 Nov 2017, Jon Steinhart wrote:
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.
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.
12:18 p.m.
Hi Andrew,
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.
A slash has long been used to separate items in a hierarchy, e.g.
division, department, staff initials, or account, purchase-order number,
at least back to the early twentieth century. So choosing it might have
seemed natural.
https://en.wikipedia.org/wiki/Slash_(punctuation)#Presenting_routes
And Multics had some kind of `attach' and `detach' of I/O streams, well
known to Ossanna, so perhaps dup(2), and a Thompson-shell syntax to go
with it meant `>' was earmarked early on.
--
Cheers, Ralph.
https://plus.google.com/+RalphCorderoy
12:49 p.m.
On 28 Nov 2017 11:18 +0000, from ralph(a)inputplus.co.uk (Ralph Corderoy):
And Multics had some kind of `attach' and
`detach' of I/O streams, well
known to Ossanna, so perhaps dup(2), and a Thompson-shell syntax to go
with it meant `>' was earmarked early on.
Didn't early UNIX pipes use `<' to separate the commands involved?
--
Michael Kjörling • https://michael.kjorling.se • michael(a)kjorling.se
“People who think they know everything really annoy
those of us who know we don’t.” (Bjarne Stroustrup)
1:46 p.m.
Hi Michael,
Didn't early UNIX pipes use `<' to
separate the commands involved?
No, you're thinking of `^'.
$ /usr/heirloom/bin/sh
$ date ^ wc
1 4 30
$ ^D
--
Cheers, Ralph.
https://plus.google.com/+RalphCorderoy
7:01 p.m.
My theory was always that the Designers had the good sense to use ‘/‘ for a directory
separator just because it was a lower case character and thus vastly easier to type than
‘>’.
-L
8:36 p.m.
On 11/28/17, Andrew Warkentin <andreww591(a)gmail.com> wrote:
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).
That's how I remember it. I think slash was chosen because it looks
somewhat like a toggle switch. MS/DOS patterned its command line
syntax after RT-11 and inherited the slash as a command option
introduction from there. Unfortunately this meant that they couldn't
use slash as a directory separator when they got a hierarchical file
system, and so they chose backslash instead. Nowadays the Windows
shell, and I think also the underlying image activation system
service, use an ugly algorithmic hack to support both directions of
slashes in file pathnames.
-Paul W.
9:03 p.m.
On Tue, Nov 28, 2017 at 2:36 PM, Paul Winalski <paul.winalski(a)gmail.com>
wrote:
MS/DOS patterned its command line
syntax after RT-11 and inherited the slash as a command option
introduction from there.
Minor correction... To do a CDC style patient zero history ;-) RT11 took
it from DOS/8, CP/M took it from RT11, then finally DOS-86 which became
PC-DOS ney MS/DOS took it from CP/M.
7:28 a.m.
On Monday, 27 November 2017 at 21:51:13 -0800, Jon Steinhart wrote:
Does anybody know the history of dash options? Were
they
a UNIX thing or did UNIX borrow them from something earlier?
If you mean specificall the dash, I can't help much. But there were
similar ideas elsewhere. UNIVAC EXEC-8 (for the 1108, late 1960s) had
options that followed the command with a comma, like:
@RUN,G GOPU,STANDARD,STANDARD
@ADD,PL ASGDMS . ASSIGNIERT DATENBASIS
@ASG,A PF. . PF IST PROGRAMM-FILE MIT GOPU
@XQT PF.GOPU
The letters after the comma were option letters, conveniently packed
into a machine word so that they didn't require parsing.
OMEGA on the Univac 494 had something similar, but delimited by a
space rather than a comma, reminiscent of earlier tar syntax.
I don't know any other systems, but since UNIVAC and Unix aren't
closely related, I'd guess that there were similar ideas elsewhere
too.
Greg
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29 Nov
29 Nov
8:16 p.m.
Greg 'groggy' Lehey <grog(a)lemis.com> wrote:
|On Monday, 27 November 2017 at 21:51:13 -0800, Jon Steinhart wrote:
|> Does anybody know the history of dash options? Were they
|> a UNIX thing or did UNIX borrow them from something earlier?
|
|If you mean specificall the dash, I can't help much. But there were
|similar ideas elsewhere. UNIVAC EXEC-8 (for the 1108, late 1960s) had
|options that followed the command with a comma, like:
|
| @RUN,G GOPU,STANDARD,STANDARD
| @ADD,PL ASGDMS . ASSIGNIERT DATENBASIS
"WEIßT DATENBASIS ZU" or "ZUWEISUNG DATENBASIS"
| @ASG,A PF. . PF IST PROGRAMM-FILE MIT GOPU
"PF IST PROGRAMM-DATEI MIT GOPU" or so.
| @XQT PF.GOPU
|
|The letters after the comma were option letters, conveniently packed
|into a machine word so that they didn't require parsing.
Or. Or the person who wrote the code above knew how German will
look like 50 years later. Which could very well be, of course.
I am still impressed by the Lidlicker film the URL of which was
posted on this list, and the spirit and, well, let me say
progressiveness of the intellect of all the portrayed persons.
It was elevating to witness and also, a bit, become reminded of
this America in 2017. A few weeks ago i could not do any
different but spent quite a few hours reading and thinking about,
and admiring Jacqueline Kennedy! I was born almost a decade
later, but nonetheless seeing her sitting straight beside the
remains of her husband, i will never admire this woman enough.
And her naturalness.
--steffen
|
|Der Kragenbaer, The moon bear,
|der holt sich munter he cheerfully and one by one
|einen nach dem anderen runter wa.ks himself off
|(By Robert Gernhardt)
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10 comments
10 participants
participants (10)
-
Andrew Warkentin -
Clem Cole -
Dave Horsfall -
Greg 'groggy' Lehey -
Jon Steinhart -
Lawrence Stewart -
Michael Kjörling -
Paul Winalski -
Ralph Corderoy -
Steffen Nurpmeso