Null tilde expansions?

Null tilde expansions?

[Greg Badros]

Is there any way to make ~notauser not cause an error (similar to the
null globbing option)?

I'd like this to give me the home directories of all the users in group oo_gang

users=(`ypcat group  | awk -F: '/^oo_gang\>/ { printf $4 }' | tr , ' '`)
dirs=~$^users

without first having to eliminate users from $users which no longer
exist (our sysadmins aren't good about eliminating users from groups
when the remove the user account).

Thanks,
Greg

Re: Null tilde expansions?

[Sweth Chandramouli]

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On Tue, Oct 06, 1998 at 11:16:28AM -0700, Greg Badros wrote:
> exist (our sysadmins aren't good about eliminating users from groups
> when the remove the user account).
	don't know about how to do what you want in zsh, but here's a 
quick perl script i whipped up a week ago to do what your sysadmins
aren't doing.  set $groupfile_out to something else at first, to test,
since i don't want to be responsible for anything happening to your system.
(this assumes you can either run this script as root or convince your
admins to, of course...)

	-- sweth.

-- 
Sweth Chandramouli
IS Coordinator, The George Washington University
<sweth@gwu.edu> / (202) 994 - 8521 (V) / (202) 994 - 0458 (F)
<a href="http://astaroth.nit.gwu.edu/~sweth/disc.html">*</a>

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Re: Null tilde expansions?

[Bart Schaefer]

On Oct 6, 11:16am, Greg Badros wrote:
} Subject: Null tilde expansions?
}
} Is there any way to make ~notauser not cause an error (similar to the
} null globbing option)?

unsetopt badpattern
users=(`ypcat group  | awk -F: '/^oo_gang\>/ { printf $4 }' | tr , ' '`)
dirs=(~$^users)
dirs=(${(M)dirs:#~)

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com

Re: Null tilde expansions?

[Greg Badros]

"Bart Schaefer" <schaefer@brasslantern.com> writes:

> On Oct 6, 11:16am, Greg Badros wrote:
> } Subject: Null tilde expansions?
> }
> } Is there any way to make ~notauser not cause an error (similar to the
> } null globbing option)?
> 
> unsetopt badpattern
> users=(`ypcat group  | awk -F: '/^oo_gang\>/ { printf $4 }' | tr , ' '`)
> dirs=(~$^users)
> dirs=(${(M)dirs:#~)

This doesn't work for me with Zsh 3.1.4 (few if any patches) or Zsh 3.0.5:

% unsetopt badpattern
% echo ~notauser
zsh: no such user or named directory: notauser

The badpattern option does look like the right thing, but perhaps it's broken?

Thanks for the response...

Greg

Re: Null tilde expansions?

[Peter Stephenson]

Greg Badros wrote:
> "Bart Schaefer" <schaefer@brasslantern.com> writes:
> % unsetopt badpattern
> % echo ~notauser
> zsh: no such user or named directory: notauser
> 
> The badpattern option does look like the right thing, but perhaps
> it's broken?

I think the appropriate option is 'nomatch'.  (Sounds OK to me, it's a
match that's failing rather than a pattern that's been typed wrongly.)

% setopt nomatch
% echo ~nouser
zsh: no such user or named directory: nouser
% setopt nonomatch
% echo ~nouser    
~nouser
% 

-- 
Peter Stephenson <pws@ibmth.df.unipi.it>       Tel: +39 050 844536
WWW:  http://www.ifh.de/~pws/
Dipartimento di Fisica, Via Buonarotti 2, 56100 Pisa, Italy

Re: Null tilde expansions?

[Bart Schaefer]

On Oct 7,  8:00am, Greg Badros wrote:
} Subject: Re: Null tilde expansions?
}
} "Bart Schaefer" <schaefer@brasslantern.com> writes:
} 
} > On Oct 6, 11:16am, Greg Badros wrote:
} > } Subject: Null tilde expansions?
} > }
} > } Is there any way to make ~notauser not cause an error (similar to the
} > } null globbing option)?
} > 
} > unsetopt badpattern
} 
} This doesn't work for me with Zsh 3.1.4 (few if any patches) or Zsh 3.0.5:

In the words of Geoff Wing: I hate it when I stuff up a post.

unsetopt badpattern nomatch


-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com

Re: Null tilde expansions?

[Greg Badros]

"Bart Schaefer" <schaefer@brasslantern.com> writes:

> On Oct 7,  8:00am, Greg Badros wrote:
> } Subject: Re: Null tilde expansions?
> }
> } "Bart Schaefer" <schaefer@brasslantern.com> writes:
> } 
> } > On Oct 6, 11:16am, Greg Badros wrote:
> } > } Subject: Null tilde expansions?
> } > }
> } > } Is there any way to make ~notauser not cause an error (similar to the
> } > } null globbing option)?
> } > 
> } > unsetopt badpattern
> } 
> } This doesn't work for me with Zsh 3.1.4 (few if any patches) or Zsh 3.0.5:
> 
> In the words of Geoff Wing: I hate it when I stuff up a post.
> 
> unsetopt badpattern nomatch

Thanks.  There were also some problems with the removing of ~notauser
words that you suggested:

 > dirs=(${(M)dirs:#~)

Besides the obvious typo of a closing paren for a closing brace, there
are three problems:

1) I want the (R)est, not the match, right?

2) The ~ needs to be escaped, otherwise it'll get expanded.  So what
actually works for me in Zsh-3.1.4 and Zsh-3.0.x is:

3) The pattern after the # needs to match the whole word, so it needs a
trailing *.

echo ${(R)dirs:#\~*}   # words that do not start with ~

#or

echo ${(M)dirs:#/*}    # words that start with /


Thanks again for your pointers and suggestions.  (And thanks to Peter
Stephenson as well!)

Greg

Re: Null tilde expansions?

[Bart Schaefer]

On Oct 7,  5:11pm, Peter Stephenson wrote:
} Subject: Re: Null tilde expansions?
}
} I think the appropriate option is 'nomatch'.  (Sounds OK to me, it's a
} match that's failing rather than a pattern that's been typed wrongly.)

I first tried it with just no_nomatch, and got an error.  However, now
that I fool with it again, I must have mistyped something else, because
it is indeed only no_nomatch that's required.

On Oct 7,  8:41am, Greg Badros wrote:
} Subject: Re: Null tilde expansions?
}
}  > dirs=(${(M)dirs:#~)
} 
} Besides the obvious typo of a closing paren for a closing brace, there
} are three problems:
} 
} 1) I want the (R)est, not the match, right?
} 2) The ~ needs to be escaped, otherwise it'll get expanded.
} 3) The pattern after the # needs to match the whole word, so it needs a
} trailing *.

Bleah.  This is what I get for testing stuff on a machine where the only
home directory is my own, so the expansion of the only valid username
"accidentally" matches the expansion of ~.

Yes, you're right.  Or just ${dirs##~*}, in which the ~ is not expanded
in the first place.

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com

Re: Null tilde expansions?

[Greg Badros]

"Bart Schaefer" <schaefer@brasslantern.com> writes:

> On Oct 7,  8:41am, Greg Badros wrote:
> } Subject: Re: Null tilde expansions?
> }
> }  > dirs=(${(M)dirs:#~)
> } 
> } Besides the obvious typo of a closing paren for a closing brace, there
> } are three problems:
> } 
> } 1) I want the (R)est, not the match, right?
> } 2) The ~ needs to be escaped, otherwise it'll get expanded.
> } 3) The pattern after the # needs to match the whole word, so it needs a
> } trailing *.
> 
> Bleah.  This is what I get for testing stuff on a machine where the only
> home directory is my own, so the expansion of the only valid username
> "accidentally" matches the expansion of ~.
> 
> Yes, you're right.  Or just ${dirs##~*}, in which the ~ is not expanded
> in the first place.

Why does the ~ not get expanded?  This doesn't work in 3.1.4 or 3.0.x
for me.  I need to escape the ~ with a backslash here, too.

Greg

Re: Null tilde expansions?

[Bart Schaefer]

On Oct 7, 10:50am, Greg Badros wrote:
} Subject: Re: Null tilde expansions?
}
} > Yes, you're right.  Or just ${dirs##~*}, in which the ~ is not expanded
} > in the first place.
} 
} Why does the ~ not get expanded?  This doesn't work in 3.1.4 or 3.0.x
} for me.  I need to escape the ~ with a backslash here, too.

I dunno, but:

aztec[26] gunk=(schaefer glorb bobg flarn fox)
aztec[27] dirs=(~$^gunk)
zsh: no such user or named directory: glorb
aztec[28] setopt nonomatch
aztec[29] dirs=(~$^gunk)
aztec[30] echo ${dirs##~*}
/home/schaefer /home/bobg /home/fox
aztec[31] echo $dirs
/home/schaefer ~glorb /home/bobg ~flarn /home/fox
aztec[32] echo $ZSH_VERSION
3.0.5-extended

(3.0.5-extended is 3.0.5 plus my patch collection, available on
ftp.brasslantern.com.)

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com

Re: Null tilde expansions?

[Peter Stephenson]

On Oct 7, 10:50am, Greg Badros wrote:
} Subject: Re: Null tilde expansions?
}
} > Yes, you're right.  Or just ${dirs##~*}, in which the ~ is not expanded
} > in the first place.
} 
} Why does the ~ not get expanded?  This doesn't work in 3.1.4 or 3.0.x
} for me.  I need to escape the ~ with a backslash here, too.

% echo $dirs
/home/user2/pws ~foobar
% unsetopt extendedglob
% echo ${dirs##~*}     
/home/user2/pws
% setopt extendedglob
% echo ${dirs##~*}   
/home/user2/pws ~foobar

-- 
Peter Stephenson <pws@ibmth.df.unipi.it>       Tel: +39 050 844536
WWW:  http://www.ifh.de/~pws/
Dipartimento di Fisica, Via Buonarotti 2, 56100 Pisa, Italy