🚀 go-pugleaf

In article <DJM.90Ap...@egypt.eng.umd.edu> d...@eng.umd.edu
(David J. MacKenzie) writes:

| Does anyone know how the Unix "dd" command got its name?
| I have a theory, based purely on reading the manual page, which in
| SunOS4 begins (I think it was similar in the V7 manual):
| 
| NAME
|      dd	- convert and copy files with various data formats
| 
| My guess is that the original author wanted to call it "cc", for
| "convert and copy", but since the name "cc" was already taken, chose
| the next letter in the alphabet and called it "dd".  Does anyone have
| a more authoritative answer?

Dd comes from IBM JCL (it's used to create datasets for the job), and
in fact the argument syntax is reminsent of what little I remember of
the JCL syntax.  Since one of the primary tasks that the original UNIX
was put to was remote job entry for IBM systems, I imagine some Bell
Labs type thought s/he was being clever.
--
Michael Meissner	email: meis...@osf.org		phone: 617-621-8861
Open Software Foundation, 11 Cambridge Center, Cambridge, MA

Catproof is an oxymoron, Childproof is nearly so

In article <DJM.90Ap...@egypt.eng.umd.edu> d...@eng.umd.edu (David J. MacKenzie) writes:
>Does anyone know how the Unix "dd" command got its name?

I assume that it stands for "data dump," or something similar.  Of
course, having bungled the options a few times, I have grown to
think that it is related to the vi "dd" command.
-- 
Christopher Pettus, Network Connectivity Development, Apple Computer, Inc.
MS 35-K -- 408/974-0004 -- c...@apple.com -- sun!apple!cep -- link PETTUS.C

meis...@osf.org (Michael Meissner) writes:
>Dd comes from IBM JCL (it's used to create datasets for the job), and
>in fact the argument syntax is reminsent of what little I remember of
>the JCL syntax.  Since one of the primary tasks that the original UNIX
>was put to was remote job entry for IBM systems, I imagine some Bell
>Labs type thought s/he was being clever.

I got the impression that UNIX was used primarily for text processing
originally (that was the whole idea, wasn't it?) and not for IBM
remote job entry at all.  Certainly there seems to be no leftover
cruft (either messages or /dev entries) to signify that it was ever
used for doing IBM job entry, unlike the CAT phototypesetter.

Perhaps I'm misunderstanding "original UNIX."

Happy hacking,

jim frost
saber software
ji...@saber.com

In article <DJM.90Ap...@egypt.eng.umd.edu> d...@eng.umd.edu (David J. MacKenzie) writes:
>Does anyone know how the Unix "dd" command got its name?
>
>My guess is that the original author wanted to call it "cc", for
>"convert and copy", but since the name "cc" was already taken, chose
>the next letter in the alphabet and called it "dd".  Does anyone have
>a more authoritative answer?

Not a more authoritative answer but my guess is simply:
    "dd" = Dump data

-- 
==============================================================================
Terry Lalonde (613)592-2122       Revenge is a confession of pain. (Seneca)
Internet: mitel!lalonde@uunet     Usenet:  ...!uunet!mitel!lalonde
==============================================================================

In article <DJM.90Ap...@egypt.eng.umd.edu> d...@eng.umd.edu (David J. MacKenzie) writes:
>Does anyone know how the Unix "dd" command got its name?

I read (I think in UnixWorld, or some other magazine) that it stood
for DarneD if I know, but I don't know whether to believe this or
not.  (No, I'm not making think up, btw.)

Henry



---
Henry Throop
Internet: thr...@jacobs.cs.orst.edu

In article <1990Apr18.0...@world.std.com> ma...@world.std.com
(jim frost) writes:

| meis...@osf.org (Michael Meissner) writes:
| >Dd comes from IBM JCL (it's used to create datasets for the job), and
| >in fact the argument syntax is reminsent of what little I remember of
| >the JCL syntax.  Since one of the primary tasks that the original UNIX
| >was put to was remote job entry for IBM systems, I imagine some Bell
| >Labs type thought s/he was being clever.
| 
| I got the impression that UNIX was used primarily for text processing
| originally (that was the whole idea, wasn't it?) and not for IBM
| remote job entry at all.  Certainly there seems to be no leftover
| cruft (either messages or /dev entries) to signify that it was ever
| used for doing IBM job entry, unlike the CAT phototypesetter.
| 
| Perhaps I'm misunderstanding "original UNIX."

Well there is the GECOS field in the password file.
--
Michael Meissner	email: meis...@osf.org		phone: 617-621-8861
Open Software Foundation, 11 Cambridge Center, Cambridge, MA

Catproof is an oxymoron, Childproof is nearly so

>>Does anyone know how the Unix "dd" command got its name?

I always thought it came from its nickname -- we used to call it "data
dump" waybackwhen.

-- 
Brain fried.  (Explanation is in file "core".)

In article <DJM.90Ap...@egypt.eng.umd.edu> d...@eng.umd.edu (David J. MacKenzie) writes:
>Does anyone know how the Unix "dd" command got its name?

I always thought it came from Device to Device copy.

Cheers,
    -Ken K
-- 
Ken Konecki
"Eat well, stay fit, die anyway"
e-mai...@tellabs.com    -or-    ...!uunet!tellab5!kenk	
U.S. Mail: 1271 Portchester Circle, Carol Stream, IL 60188

In article <1990Apr18.0...@world.std.com> ma...@world.std.com (jim frost) writes:
>
>I got the impression that UNIX was used primarily for text processing
>originally (that was the whole idea, wasn't it?) and not for IBM
>remote job entry at all.  Certainly there seems to be no leftover
>cruft (either messages or /dev entries) to signify that it was ever
>used for doing IBM job entry, unlike the CAT phototypesetter.
>
>Perhaps I'm misunderstanding "original UNIX."
>
I'm pretty sure Unix was originally developed so its creators could
play Space War.

-- 
		-Chip
Chip Christian
AT&T Bell Laboratories
Murray Hill, NJ
ch...@allegra.research.att.com
"We've got a kinder, gentler machine gun hand..."
AT&T_opinions = ! my_opinions;

>Does anyone know how the Unix "dd" command got its name?

It's a play on the IBM/JCL DD command, DD stood for DATA DEFINITION in
JCL and was how you attached files to a job. All files had to be
pre-allocated and were defined externally to the job, sort of like the
Unix < and > commands only absurdly complicated.

The cards looked like:

	//sysin dd *

which meant attach the symbolic input name (sysin) to the rest of this
card deck (*), but more telling are things like:

	//sysin dd lrecl=80,blksiz=800,disp=(new,new,save),
		   space=(20,20,rlse)

(hmm, doesn't look quite right, who cares)

starting to look familiar? There were around 200 options available,
and the defaults were almost always wrong...

The job accessed the symbol SYSIN (or whatever, you just made it up,
but a lot of packages used SYSIN, SYSOUT, SYSPRINT and SYSPUNCH as a
standard) as if it were a file and the file was attached externally
through a DSNAME (data set name) card who's format was described in
the DD card.

Let's put it this way, it took a reasonably seasoned programmer to
just make a copy of a file...

The fun part was that JCL errors where I worked years ago cost about
$1.50 each due to minimum costs of running one job through and having
it bomb out. I went through over $1,000 one evening, in real money,
trying to get one lousy JCL bug out which turned out to be a change
someone in systems had made in a standard JCL utility program...

The point being, DD cards were loathsome things so making a Unix
command with that name was black humor.

-- 
        -Barry Shein

Software Tool & Die    | {xylogics,uunet}!world!bzs | b...@world.std.com
Purveyors to the Trade | Voice: 617-739-0202        | Login: 617-739-WRLD

In article <1990Apr22.1...@world.std.com> b...@world.std.com (Barry Shein) writes:
>	//sysin dd lrecl=80,blksiz=800,disp=(new,new,save),
>		   space=(20,20,rlse)

	//SYSIN	DD	DCB=(LRECL-80,BLKSIZE=800,RECFM=FB),
	//		DISP=(OLD,KEEP),SPACE=(20,20,,RLSE),
	//		DSN=C1882P.FOO.BAR.BAZ.WOOF

>(hmm, doesn't look quite right, who cares)

							spl (the p stands for
							//PUNCH DD SYSOUT=B)
--
Steve Lamont, sciViGuy	(919) 248-1120		EMail:	s...@ncsc.org
NCSC (The other one), Box 12732, Research Triangle Park, NC 27709
Don't send in no bums.  I want deals.
				-John Steinbeck, _The Grapes of Wrath_

In article <19...@speedy.mcnc.org> s...@duck.ncsc.org (Steve Lamont) writes:
>In article <1990Apr22.1...@world.std.com> b...@world.std.com (Barry Shein) writes:
>>	//sysin dd lrecl=80,blksiz=800,disp=(new,new,save),
>>		   space=(20,20,rlse)
>
>	//SYSIN	DD	DCB=(LRECL-80,BLKSIZE=800,RECFM=FB),
>	//		DISP=(OLD,KEEP),SPACE=(20,20,,RLSE),
>	//		DSN=C1882P.FOO.BAR.BAZ.WOOF
>
>>(hmm, doesn't look quite right, who cares)

Nope, still wouldn't work. You left out device type and volser,
unless you're assuming it was a cataloged dataset in either the
JOBLIB or STEPLIB cards.

//SYSIN DD      DSN=C1882P.FOO.BAR.BAZ.WOOF,
//              UNIT=DISK,
//              VOL=SER=VSPK01,
//              DCB=(LRECL=80,RECFM=FB,BLKSIZE=800),
//              DISP=(OLD,KEEP,KEEP),
//              SPACE=(20,20,5,RLSE)

>Steve Lamont, sciViGuy	(919) 248-1120		EMail:	s...@ncsc.org


Anybody else remember *why* it was a good idea to put all your JCL
parms on separate lines?
-- 
David Boyes       |  "Where's the ka-boom? There's supposed to be an
dbo...@rice.edu   |  Earth-shattering ka-boom!...Heavens! Someone has
                  |  stolen the Illudium Q-38 Explosive Space Modulator!
"Delays, delays!" |  The Earth creature has *stolen* the Space Modulator!"

In article <69...@brazos.Rice.edu> dbo...@brazos.rice.edu (David Boyes) writes:
}//SYSIN DD      DSN=C1882P.FOO.BAR.BAZ.WOOF,
}//              UNIT=DISK,
}//              VOL=SER=VSPK01,
}//              DCB=(LRECL=80,RECFM=FB,BLKSIZE=800),
}//              DISP=(OLD,KEEP,KEEP),
}//              SPACE=(20,20,5,RLSE)

}Anybody else remember *why* it was a good idea to put all your JCL
}parms on separate lines?

Because they were punched on cards, of course.  Putting them on separate
lines let you change one without retyping several others.

I apprenticed in a shop that had a huge file full of standard cards.  I
got yelled at once because someone had slipped in a job card with a space
between the final parameters, causing misc. grief.  Fortunately, I was
able to go to the appropriate card file and prove that _all_ the cards had
that space, so it wasn't entirely my fault.

Does that make me an "old timer?" It was only 1981 ...

-- 
The Polymath (aka: Jerry Hollombe, M.A., CDP, aka: holl...@ttidca.tti.com)
Citicorp(+)TTI                                    Illegitimis non
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In article <1990Apr22.1...@world.std.com> b...@world.std.com (Barry Shein) writes:
[ stuff about dd including convoluted option configurations ]
# starting to look familiar? There were around 200 options available,
# and the defaults were almost always wrong...

Isn't it *usually* that way?  At least one person in any given organisation
will insist that the defaults are wrong.  Let's hear it for environment
or file-based defaults...

# 
# Let's put it this way, it took a reasonably seasoned programmer to
# just make a copy of a file...
# 

Maybe if we re-did the "rm" command like that, people wouldn't have
so many problems. :-)

# The fun part was that JCL errors where I worked years ago cost about
# $1.50 each due to minimum costs of running one job through and having
# it bomb out. I went through over $1,000 one evening, in real money,
# trying to get one lousy JCL bug out which turned out to be a change
# someone in systems had made in a standard JCL utility program...
# 
# The point being, DD cards were loathsome things so making a Unix
# command with that name was black humor.

That may be Unix' idea of black humour, but Unix has presented us with
its own nightmare.  It's called find(1).

# 
# -- 
#         -Barry Shein
# 
# Software Tool & Die    | {xylogics,uunet}!world!bzs | b...@world.std.com
# Purveyors to the Trade | Voice: 617-739-0202        | Login: 617-739-WRLD
 "
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-- 
Brain fried.  (Explanation is in file "core".)

greywolf@unisoft.UUCP (The Grey Wolf) writes:
># The point being, DD cards were loathsome things so making a Unix
># command with that name was black humor.

>That may be Unix' idea of black humour, but Unix has presented us with
>its own nightmare.  It's called find(1).

But ... you couldn't get around those "dd" statements.  There are any
number of ways to avoid using "find" if you are particularly annoyed
with its syntax.

Happy hacking,

jim frost
saber software
ji...@saber.com