[9fans] how to delete directories prefixed with a dash

[9fans] how to delete directories prefixed with a dash

[Skip Tavakkolian]

I think i did a 'mkdir -p -m 777 xxx' , before either flag was supported
and thus created a -p and a -m directory. I finally removed them by
cd'ing to those dirs and doing a 'rm .';

What's the quoting rule to get that type of name past the flags
processing in rm (or anything else that has flags)?

Re: [9fans] how to delete directories prefixed with a dash

[Geoff Collyer]

There's also the getopt convention, implemented by arg(2):

	rm -- -m -p

Re: [9fans] how to delete directories prefixed with a dash

[Don Bailey]

rm ./-p

Skip Tavakkolian wrote:

>I think i did a 'mkdir -p -m 777 xxx' , before either flag was supported
>and thus created a -p and a -m directory. I finally removed them by
>cd'ing to those dirs and doing a 'rm .';
>
>What's the quoting rule to get that type of name past the flags
>processing in rm (or anything else that has flags)?
>
>
>  
>

Re: [9fans] how to delete directories prefixed with a dash

[Russ Cox]

> I think i did a 'mkdir -p -m 777 xxx' , before either flag was supported
> and thus created a -p and a -m directory. I finally removed them by
> cd'ing to those dirs and doing a 'rm .';
> 
> What's the quoting rule to get that type of name past the flags
> processing in rm (or anything else that has flags)?

rm -- -p

Re: [9fans] how to delete directories prefixed with a dash

[Don Bailey]

sickening. I leave to party and compose some music, then come
back to find gnu9?

Geoff Collyer wrote:

>There's also the getopt convention, implemented by arg(2):
>
>	rm -- -m -p
>
>
>  
>

Re: [9fans] how to delete directories prefixed with a dash

[Charles Forsyth]

-p is one thing i suppose, but -m 777 seems a little pointless.
actually, -m probably is fairly pointless all round.

as on Unix, on Plan 9 it probably doesn't do what you might think, although
Unix and Plan 9 don't do that in different ways.  on Unix it applies
only to the last component and is subject to umask, and intervening
directories get -m $(umask -S),u+wx; on Plan 9 the mode applies to all
directories (so -m 555 -p not/there/yet won't work at all) and in
each case is subject to masking by the parent directory permissions,
so -m 777 produces completely-writable directories only if the old
create(..., DMDIR|0777) would have done anyway.  now on Plan 9,
mkdir -p -m 700 ... does make a difference (starting in a directory
with mode 755 say) and will set the mode 700 on each new
directory; although that differs from Unix where with my umask 022
i get 755 directories up to the last created, which is 700.

of course in all cases, on Plan 9 and Unix,
if mkdir doesn't create the directory (eg, intervening ones with -p), it doesn't change
the mode, so be sure to do rm -r or rm -r -- first.  that's presumably
why the Unix one has the definition it's got.  it's not that useful but it
behaves consistently not-that-usefully with -p regardless whether the directories are created or not.

at least i think so; that's what the Unix manual pages and code suggests,
supported by experiment on Plan 9 and Unix.

all in all, i confess i did wonder when it appeared several months
ago why -m was in Plan 9 outside APE.  still it's only 80 lines compared
with 212 on FreeBSD (but then that includes the BSD copyright and licence, and
			/*
			 * POSIX 1003.2:
			 * For each dir operand that does not name an existing
			 * directory, effects equivalent to those cased by the
			 * following command shall occcur:
			 *
			 * mkdir -p man 2 $(dirname dir) &&
			 *    mkdir [-m mode] dir
			 *
			 * We change the user's umask and then restore it,
			 * instead of doing chmod's.
			 */
and
		/*
		 * The mkdir() and umask() calls both honor only the low
		 * nine bits, so if you try to set a mode including the
		 * sticky, setuid, setgid bits you lose them.  Don't do
		 * this unless the user has specifically requested a mode,
		 * as chmod will (obviously) ignore the umask.
		 */

i wonder why i got out of bed this morning.
after the above, you'll probably wish i'd stayed there too!

Re: [9fans] how to delete directories prefixed with a dash

[Douglas A. Gwyn]

Don Bailey wrote:
> sickening. I leave to party and compose some music, then come
> back to find gnu9?

Getopt (including the -- convention) was developed at
Bell Labs over 20 years ago.  If you're not using it,
shame on you.

Re: [9fans] how to delete directories prefixed with a dash

[Russ Cox]

> Getopt (including the -- convention) was developed at
> Bell Labs over 20 years ago.  If you're not using it,
> shame on you.

You're preaching to the wrong crowd.
Essentially no code here uses getopt.

Russ

Re: [9fans] how to delete directories prefixed with a dash

[C H Forsyth]

[-- Attachment #1: Type: text/plain, Size: 232 bytes --]

just to avoid damnation, that's because it uses arg(2)
which is similar in intent except that it's simpler and
the interface doesn't rely on globals, so it can be used
to crack argv parameters to internal threads (if you like).

[-- Attachment #2: Type: message/rfc822, Size: 2732 bytes --]

From: Russ Cox <russcox@gmail.com>
To: Fans of the OS Plan 9 from Bell Labs <9fans@cse.psu.edu>
Subject: Re: [9fans] how to delete directories prefixed with a dash
Date: Wed, 16 Jun 2004 07:45:06 -0400
Message-ID: <ee9e417a04061604456cd6b853@mail.gmail.com>

> Getopt (including the -- convention) was developed at
> Bell Labs over 20 years ago.  If you're not using it,
> shame on you.

You're preaching to the wrong crowd.
Essentially no code here uses getopt.

Russ

Re: [9fans] how to delete directories prefixed with a dash

[boyd, rounin]

> You're preaching to the wrong crowd.

yeah, why use -- when ./ will do it?  no extra code for ./ unlike --

Re: [9fans] how to delete directories prefixed with a dash

[rog]

> yeah, why use -- when ./ will do it?  no extra code for ./ unlike --

./ won't work with grep, or other commands that
take arguments that aren't filenames.

also, in a shell script,

	rm ./$1

isn't correct.

-- is standard.

Re: [9fans] how to delete directories prefixed with a dash

[Dave Lukes]

> ./ won't work with grep, or other commands that
> take arguments that aren't filenames.

<devils-advocate>

... but grep understands \\:-).

> also, in a shell script,
> 
> 	rm ./$1
> 
> isn't correct.

Why not?

> -- is standard.

So are the above:-).

</devils-advocate>

	DaveL

Re: [9fans] how to delete directories prefixed with a dash

[Skip Tavakkolian]

> <devils-advocate>

davel's-advocate?

Re: [9fans] how to delete directories prefixed with a dash

[rog]

> ... but grep understands \\:-).

and...?

> > 	rm ./$1
> > 
> > isn't correct.
> 
> Why not?

'cos you might want to give an argument that's not relative
to the current directory?

Re: [9fans] how to delete directories prefixed with a dash

[Don Bailey]

>
> Getopt (including the -- convention) was developed at
> Bell Labs over 20 years ago.  If you're not using it,
> shame on you.


I was making a joke on how the state of things changed
while I've been gone. It seems the state of pro and
anti GNU buzz (as there always has been) has began to
escalate due to portability desires, etc. However, I
don't believe the -- issue is particularly relevant
to getopt, since plan9 doesn't even use getopt, so,
shame on you. Apparently, you don't use it either.
Worse yet, you don't know that you don't use it.

Excuse my lack of emoticons or <sarc></sarc> tags:
Booze Brother Shirani has still got me on sarcastic
time and I think I'll be experiencing jet lag for
a few more days.

Don

Re: [9fans] how to delete directories prefixed with a dash

[Geoff Collyer]

Real getopt has nothing to do with gnu.  gnu has several flavours of
extended getopt-like functions, but that's not relevant here.  I was
just pointing out that arg(2) implements the same "--" convention as
getopt, so all programs that use arg(2) for option parsing get it for
free.  And yes, I rarely use it, preferring "rm ./-p" and "grep '*-p'"
or "grep .-p".

Re: [9fans] how to delete directories prefixed with a dash

[Douglas A. Gwyn]

boyd, rounin wrote:
> yeah, why use -- when ./ will do it?  no extra code for ./ unlike --

Not all nonoption arguments that might start with a - character
are pathnames.

Re: [9fans] how to delete directories prefixed with a dash

[Dave Lukes]

rog@vitanuova.com wrote:
>>... but grep understands \\:-).
> 
> 
> and...?

... and you can do:
	grep \\-...

>>>	rm ./$1
>>>
>>>isn't correct.
>>
>>Why not?
> 
> 
> 'cos you might want to give an argument that's not relative
> to the current directory?

In which case you say
	rm /....
and there's no '-' problem, right?

	DaveL.

Re: [9fans] how to delete directories prefixed with a dash

[Dave Lukes]

Skip Tavakkolian wrote:
> davel's-advocate?
> 

Old joke.

Someone at Morgan Stanley (Brian Redman IIRC)
once enhanced my X-Face: with horns and a tail.

	D[ae]v[ei]L.