The Unix Heritage Society mailing list
 help / color / mirror / Atom feed
* [TUHS] UNIX Backslash History
@ 2019-10-26  9:39 Caipenghui
  0 siblings, 0 replies; 17+ messages in thread
From: Caipenghui @ 2019-10-26  9:39 UTC (permalink / raw)
  To: TUHS main list

[-- Attachment #1: Type: text/plain, Size: 134 bytes --]

Hello everyone,

What is the special meaning of using / as directory partition in UNIX? And \ as the escape character.

Caipenghui

[-- Attachment #2: Type: text/html, Size: 142 bytes --]

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [TUHS] UNIX Backslash History
  2019-10-28 18:47             ` Dave Horsfall
@ 2019-10-28 20:43               ` Paul Winalski
  0 siblings, 0 replies; 17+ messages in thread
From: Paul Winalski @ 2019-10-28 20:43 UTC (permalink / raw)
  To: Dave Horsfall
  Cc: The Eunuchs Hysterical Society, Computer Old Farts Followers

On 10/28/19, Dave Horsfall <dave@horsfall.org> wrote:
> On Mon, 28 Oct 2019, Steve Nickolas wrote:
>
>> 86-DOS actually did use ":" as a prompt character.  This was changed for
>> IBM's release, for some clone releases, and for MS-DOS 2.0.
>
> The best I've ever seen was RT-11's "." - talk about minimalist...
>
> Actually this thread probably belongs on COFF by now.

RT-11 was following standard DEC practice by using "." as its command
prompt.  The "monitor dot" was the command prompt in both TOPS-10 and
TOPS-20.

Most DEC operating systems, including RT-11, TOPS-10/20, and VMS, used
"/" as a prefix on command options; "-" performs this function on UNIX
since "/" is the directory delimiter.  Back in the days of stand-alone
programs, physical switches on the console were used to set program
options.  This of course won't work when you have multiprogramming.  I
was told that DEC chose "/" because it looks like a toggle switch.
Command options in fact were initially called "switches".

-Paul W.

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [TUHS] UNIX Backslash History
  2019-10-28 15:08           ` Steve Nickolas
@ 2019-10-28 18:47             ` Dave Horsfall
  2019-10-28 20:43               ` Paul Winalski
  0 siblings, 1 reply; 17+ messages in thread
From: Dave Horsfall @ 2019-10-28 18:47 UTC (permalink / raw)
  To: The Eunuchs Hysterical Society; +Cc: Computer Old Farts Followers

On Mon, 28 Oct 2019, Steve Nickolas wrote:

> 86-DOS actually did use ":" as a prompt character.  This was changed for 
> IBM's release, for some clone releases, and for MS-DOS 2.0.

The best I've ever seen was RT-11's "." - talk about minimalist...

Actually this thread probably belongs on COFF by now.

-- Dave

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [TUHS] UNIX Backslash History
  2019-10-28 17:36   ` Anthony Martin
@ 2019-10-28 18:17     ` Charles Anthony
  0 siblings, 0 replies; 17+ messages in thread
From: Charles Anthony @ 2019-10-28 18:17 UTC (permalink / raw)
  To: Anthony Martin; +Cc: The Eunuchs Hysterical Society

[-- Attachment #1: Type: text/plain, Size: 266 bytes --]

>
>
>
> Unix uses dot for the current directory. Was
> there any notation for this in Multics?
>
> Not as a special symbol. As a command parameter,   [pwd]   is equivalent
to UNIX `pwd`;  [hd]  would be equivalent to ~, evaluating to the home
directory,

-- Charles

[-- Attachment #2: Type: text/html, Size: 535 bytes --]

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [TUHS] UNIX Backslash History
  2019-10-27 20:46 ` Bakul Shah
@ 2019-10-28 17:36   ` Anthony Martin
  2019-10-28 18:17     ` Charles Anthony
  0 siblings, 1 reply; 17+ messages in thread
From: Anthony Martin @ 2019-10-28 17:36 UTC (permalink / raw)
  To: Bakul Shah; +Cc: tuhs

Bakul Shah <bakul@bitblocks.com> once said:
> >dir1>dir2>file1	-- absolute: /dir1/di2/file1
> file1			-- relative: if >dir1>dir2 is the working dir
> <file2			-- relative: ../file2 == >dir1>file2
> <dir3>file4		-- ../dir3/file3
> <<dir4>file5		-- ../../dir4/file5 == >dir4>file5
> 
> << is more compact thant ../.. and I like the vertical symmetry of < and >!

"Getting Less Than Right" would have been an
interesting title. ;)

Unix uses dot for the current directory. Was
there any notation for this in Multics?

  Anthony

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [TUHS] UNIX Backslash History
@ 2019-10-28 15:51 Noel Chiappa
  0 siblings, 0 replies; 17+ messages in thread
From: Noel Chiappa @ 2019-10-28 15:51 UTC (permalink / raw)
  To: tuhs; +Cc: jnc

    > From: Charles Anthony

    >> I think it was >user_dir_dir>Group>User, wasn't it?

    > user_dir_dir>Project>User

Oh, right. Too many years spent on Unix! :-)

    > "Names" are aliases, similar to soft links

I feel like they are more similar to hard links; they belong to a segment, and
if the name is given to another segment, and the original segment has only
that name, it goes away. (See the discussion under "add_name" in the MPM
'Commands and Active Fuinctions'). Also, Multics does real soft links (too),
so names can't be soft links! :-)

	Noel

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [TUHS] UNIX Backslash History
  2019-10-28 12:00         ` Michael Kjörling
  2019-10-28 13:44           ` Clem Cole
@ 2019-10-28 15:08           ` Steve Nickolas
  2019-10-28 18:47             ` Dave Horsfall
  1 sibling, 1 reply; 17+ messages in thread
From: Steve Nickolas @ 2019-10-28 15:08 UTC (permalink / raw)
  To: Michael Kjörling; +Cc: tuhs

[-- Attachment #1: Type: TEXT/PLAIN, Size: 815 bytes --]

On Mon, 28 Oct 2019, Michael Kjörling wrote:

> On 27 Oct 2019 21:11 -0400, from usotsuki@buric.co (Steve Nickolas):
>>
>> I can't imagine there's any such connection.  MS-DOS got it from CP/M, which
>> didn't even have the concept of subdirectories until after MS-DOS did.
>
> If there was such a relationship, it would probably make more sense
> for the command prompt termination character to be ":", not ">", as
> DOS labelled devices as [whatever]: (like "A:" or "NUL:"). So I agree
> with Steve; I imagine it's unrelated. They just had to use _something_
> as a default to indicate that the computer is waiting for a command,
> and ">" is as good a character as any.

86-DOS actually did use ":" as a prompt character.  This was changed for 
IBM's release, for some clone releases, and for MS-DOS 2.0.

-uso.

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [TUHS] UNIX Backslash History
  2019-10-28 12:00         ` Michael Kjörling
@ 2019-10-28 13:44           ` Clem Cole
  2019-10-28 15:08           ` Steve Nickolas
  1 sibling, 0 replies; 17+ messages in thread
From: Clem Cole @ 2019-10-28 13:44 UTC (permalink / raw)
  To: Michael Kjörling; +Cc: TUHS main list

[-- Attachment #1: Type: text/plain, Size: 276 bytes --]

On Mon, Oct 28, 2019 at 8:01 AM Michael Kjörling <michael@kjorling.se>
wrote:

> the question would probably need to be posed to Kildall where he got it
> from.
>
Kildall was in record stating that CP/M's model was RT-11, which came from
DOS-11 which came from DOS-8

[-- Attachment #2: Type: text/html, Size: 945 bytes --]

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [TUHS] UNIX Backslash History
  2019-10-28  1:11       ` Steve Nickolas
@ 2019-10-28 12:00         ` Michael Kjörling
  2019-10-28 13:44           ` Clem Cole
  2019-10-28 15:08           ` Steve Nickolas
  0 siblings, 2 replies; 17+ messages in thread
From: Michael Kjörling @ 2019-10-28 12:00 UTC (permalink / raw)
  To: tuhs

On 27 Oct 2019 21:11 -0400, from usotsuki@buric.co (Steve Nickolas):
> On Sun, 27 Oct 2019, Grant Taylor via TUHS wrote:
>> Is there any relation between Multics' use of ">" as a directory
>> separator and MS-DOS's default use of ">" at the end of the command
>> prompt?
> 
> I can't imagine there's any such connection.  MS-DOS got it from CP/M, which
> didn't even have the concept of subdirectories until after MS-DOS did.

If there was such a relationship, it would probably make more sense
for the command prompt termination character to be ":", not ">", as
DOS labelled devices as [whatever]: (like "A:" or "NUL:"). So I agree
with Steve; I imagine it's unrelated. They just had to use _something_
as a default to indicate that the computer is waiting for a command,
and ">" is as good a character as any.

In either case, since MS-DOS/PC-DOS did what CP/M already did in that
regard, the question would probably need to be posed to Kildall where
he got it from. Unless Kildall wrote it down, getting a first hand
account on the reasoning behind that particular choice would be...
nontrivial.

-- 
Michael Kjörling • https://michael.kjorling.se • michael@kjorling.se
  “The most dangerous thought that you can have as a creative person
              is to think you know what you’re doing.” (Bret Victor)


^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [TUHS] UNIX Backslash History
  2019-10-27 23:01     ` Grant Taylor via TUHS
@ 2019-10-28  1:11       ` Steve Nickolas
  2019-10-28 12:00         ` Michael Kjörling
  0 siblings, 1 reply; 17+ messages in thread
From: Steve Nickolas @ 2019-10-28  1:11 UTC (permalink / raw)
  To: Grant Taylor; +Cc: tuhs

[-- Attachment #1: Type: TEXT/PLAIN, Size: 453 bytes --]

On Sun, 27 Oct 2019, Grant Taylor via TUHS wrote:

> On 10/27/19 2:49 PM, Charles Anthony wrote:
>> /home/CAnthony     >user_dir_dir>User>CAnthony
> Is there any relation between Multics' use of ">" as a directory separator 
> and MS-DOS's default use of ">" at the end of the command prompt?

I can't imagine there's any such connection.  MS-DOS got it from CP/M, 
which didn't even have the concept of subdirectories until after MS-DOS 
did.

-uso.

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [TUHS] UNIX Backslash History
  2019-10-27 20:49   ` Charles Anthony
@ 2019-10-27 23:01     ` Grant Taylor via TUHS
  2019-10-28  1:11       ` Steve Nickolas
  0 siblings, 1 reply; 17+ messages in thread
From: Grant Taylor via TUHS @ 2019-10-27 23:01 UTC (permalink / raw)
  To: tuhs

[-- Attachment #1: Type: text/plain, Size: 282 bytes --]

On 10/27/19 2:49 PM, Charles Anthony wrote:
> /home/CAnthony     >user_dir_dir>User>CAnthony
Is there any relation between Multics' use of ">" as a directory 
separator and MS-DOS's default use of ">" at the end of the command prompt?



-- 
Grant. . . .
unix || die


[-- Attachment #2: S/MIME Cryptographic Signature --]
[-- Type: application/pkcs7-signature, Size: 4008 bytes --]

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [TUHS] UNIX Backslash History
  2019-10-27 21:31 Noel Chiappa
@ 2019-10-27 21:51 ` Charles Anthony
  0 siblings, 0 replies; 17+ messages in thread
From: Charles Anthony @ 2019-10-27 21:51 UTC (permalink / raw)
  To: Noel Chiappa; +Cc: The Eunuchs Hysterical Society

[-- Attachment #1: Type: text/plain, Size: 1035 bytes --]

On Sun, Oct 27, 2019 at 2:31 PM Noel Chiappa <jnc@mercury.lcs.mit.edu>
wrote:

>     > From: Charles Anthony
>
>     > /home/CAnthony
>
> I think it was >user_dir_dir>Group>User, wasn't it? I seem to remember my
> homedir on MIT-Multics was >udd>CSR>JNChiappa?
>
>
>user_dir_dir>Project>User

>user_dir_dir          Home directories of users
>daemon_dir_dir    Home directories of daemons
>process_dir_dir    /proc

"Names" are aliases, similar to soft links; "udd" is a name for
"user_dir_dir" so ">udd" and ">user_dir_dir" point to the same directory.

>user_dir_dir>SysAdmin>admin    or   >udd>sa>a   is  ~root/

Circulating back to the original question, backslash is used as an escape
character on Multics.  "\f" is end-of-file-ish, used eg to leave input mode
in text editors.

-- Charles

And I wonder if the 'dd' directory on PDP-7 Unix owe anything to 'udd'?
>
> Getting back to the original query, I'm wondering if '/' was picked
> as it wasn't shifted, unlike '>'?
>
>    Noel
>


-- 
X-Clacks-Overhead: GNU Terry Pratchett

[-- Attachment #2: Type: text/html, Size: 2083 bytes --]

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [TUHS] UNIX Backslash History
@ 2019-10-27 21:31 Noel Chiappa
  2019-10-27 21:51 ` Charles Anthony
  0 siblings, 1 reply; 17+ messages in thread
From: Noel Chiappa @ 2019-10-27 21:31 UTC (permalink / raw)
  To: tuhs; +Cc: jnc

    > From: Charles Anthony

    > /home/CAnthony     

I think it was >user_dir_dir>Group>User, wasn't it? I seem to remember my
homedir on MIT-Multics was >udd>CSR>JNChiappa?

And I wonder if the 'dd' directory on PDP-7 Unix owe anything to 'udd'?

Getting back to the original query, I'm wondering if '/' was picked
as it wasn't shifted, unlike '>'?

   Noel

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [TUHS] UNIX Backslash History
  2019-10-27 20:42 ` Richard Salz
@ 2019-10-27 20:49   ` Charles Anthony
  2019-10-27 23:01     ` Grant Taylor via TUHS
  0 siblings, 1 reply; 17+ messages in thread
From: Charles Anthony @ 2019-10-27 20:49 UTC (permalink / raw)
  To: Richard Salz; +Cc: The Eunuchs Hysterical Society, Doug McIlroy

[-- Attachment #1: Type: text/plain, Size: 266 bytes --]

On Sun, Oct 27, 2019 at 1:43 PM Richard Salz <rich.salz@gmail.com> wrote:

>
>> Multics had a hierarchical file system, too, but I don't recall how
>> pathnames were punctuated.
>>
>
> >
>
>>
/home/CAnthony     >user_dir_dir>User>CAnthony

../foo   <foo

-- Charles

[-- Attachment #2: Type: text/html, Size: 1114 bytes --]

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [TUHS] UNIX Backslash History
  2019-10-27 20:31 Doug McIlroy
  2019-10-27 20:42 ` Richard Salz
@ 2019-10-27 20:46 ` Bakul Shah
  2019-10-28 17:36   ` Anthony Martin
  1 sibling, 1 reply; 17+ messages in thread
From: Bakul Shah @ 2019-10-27 20:46 UTC (permalink / raw)
  To: tuhs

On Sun, 27 Oct 2019 16:31:28 -0400 Doug McIlroy <doug@cs.dartmouth.edu> wrote:
> > What is the special meaning of using / as directory partition in UNIX? And 
> \ as  the escape character.
>
> \ came from Multics. The first day Multics ran at Bell Labs Bob Morris
> famously typed backslash-newline at the login prompt and crashed the
> system.
>
> Multics had a hierarchical file system, too, but I don't recall how
> pathnames were punctuated.

From what I read:

>dir1>dir2>file1	-- absolute: /dir1/di2/file1
file1			-- relative: if >dir1>dir2 is the working dir
<file2			-- relative: ../file2 == >dir1>file2
<dir3>file4		-- ../dir3/file3
<<dir4>file5		-- ../../dir4/file5 == >dir4>file5

<< is more compact thant ../.. and I like the vertical symmetry of < and >!

^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [TUHS] UNIX Backslash History
  2019-10-27 20:31 Doug McIlroy
@ 2019-10-27 20:42 ` Richard Salz
  2019-10-27 20:49   ` Charles Anthony
  2019-10-27 20:46 ` Bakul Shah
  1 sibling, 1 reply; 17+ messages in thread
From: Richard Salz @ 2019-10-27 20:42 UTC (permalink / raw)
  To: Doug McIlroy; +Cc: The Eunuchs Hysterical Society

[-- Attachment #1: Type: text/plain, Size: 111 bytes --]

>
>
> Multics had a hierarchical file system, too, but I don't recall how
> pathnames were punctuated.
>

>

>

[-- Attachment #2: Type: text/html, Size: 512 bytes --]

^ permalink raw reply	[flat|nested] 17+ messages in thread

* [TUHS] UNIX Backslash History
@ 2019-10-27 20:31 Doug McIlroy
  2019-10-27 20:42 ` Richard Salz
  2019-10-27 20:46 ` Bakul Shah
  0 siblings, 2 replies; 17+ messages in thread
From: Doug McIlroy @ 2019-10-27 20:31 UTC (permalink / raw)
  To: tuhs

> What is the special meaning of using / as directory partition in UNIX? And \ as  the escape character.

\ came from Multics. The first day Multics ran at Bell Labs Bob Morris
famously typed backslash-newline at the login prompt and crashed the
system.

Multics had a hierarchical file system, too, but I don't recall how
pathnames were punctuated.

Doug

^ permalink raw reply	[flat|nested] 17+ messages in thread

end of thread, other threads:[~2019-10-28 20:43 UTC | newest]

Thread overview: 17+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-10-26  9:39 [TUHS] UNIX Backslash History Caipenghui
2019-10-27 20:31 Doug McIlroy
2019-10-27 20:42 ` Richard Salz
2019-10-27 20:49   ` Charles Anthony
2019-10-27 23:01     ` Grant Taylor via TUHS
2019-10-28  1:11       ` Steve Nickolas
2019-10-28 12:00         ` Michael Kjörling
2019-10-28 13:44           ` Clem Cole
2019-10-28 15:08           ` Steve Nickolas
2019-10-28 18:47             ` Dave Horsfall
2019-10-28 20:43               ` Paul Winalski
2019-10-27 20:46 ` Bakul Shah
2019-10-28 17:36   ` Anthony Martin
2019-10-28 18:17     ` Charles Anthony
2019-10-27 21:31 Noel Chiappa
2019-10-27 21:51 ` Charles Anthony
2019-10-28 15:51 Noel Chiappa

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).