[[ -f file* ]]

[[ -f file* ]]

[Atom Smasher]

if i want to test for the presence of one or more files matching a certain 
pattern, it seems non-trivial to do it with the normal "test" or 
conditional expressions.

so far this seems like the best way to do it:
 	{ ls test* } 2> /dev/null | read -k 2 -u 0

if one or more files match the pattern "test*", read returns 0. if no 
files match the pattern, read returns >0.

is there a better way?

thanks...


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Re: [[ -f file* ]]

[Matt Wozniski]

On Mon, May 18, 2009 at 5:14 AM, Atom Smasher wrote:
> if i want to test for the presence of one or more files matching a certain
> pattern, it seems non-trivial to do it with the normal "test" or conditional
> expressions.
...
> is there a better way?

Well, off the top of my head, I can think of

[ -n "$(print -- test*(N))" ]

but even that seems inelegant; I'm sure someone can chime in with
something better.

~Matt

Re: [[ -f file* ]]

[Peter Stephenson]

On Mon, 18 May 2009 05:36:18 -0400
Matt Wozniski <godlygeek@gmail.com> wrote:
> On Mon, May 18, 2009 at 5:14 AM, Atom Smasher wrote:
> > if i want to test for the presence of one or more files matching a certain
> > pattern, it seems non-trivial to do it with the normal "test" or conditional
> > expressions.
> ...
> > is there a better way?
> 
> Well, off the top of my head, I can think of
> 
> [ -n "$(print -- test*(N))" ]
> 
> but even that seems inelegant; I'm sure someone can chime in with
> something better.

has_matches() {
  (( $# > 0 ))
}

if has_matches test*(N); then
  # some matches
else
  # no matches
fi


You need to remember the (N).  There are ways around that.

-- 
Peter Stephenson <pws@csr.com>                  Software Engineer
CSR PLC, Churchill House, Cambridge Business Park, Cowley Road
Cambridge, CB4 0WZ, UK                          Tel: +44 (0)1223 692070

Re: [[ -f file* ]]

[Atom Smasher]

On Mon, 18 May 2009, Matt Wozniski wrote:

> Well, off the top of my head, I can think of
>
> [ -n "$(print -- test*(N))" ]
>
> but even that seems inelegant; I'm sure someone can chime in with 
> something better.
=================

it's less inelegant than my original method ;)

and it works fine with '[[' conditional expressions... which, IIUC, is the 
"new and improved" version of test.


-- 
         ...atom

  ________________________
  http://atom.smasher.org/
  762A 3B98 A3C3 96C9 C6B7 582A B88D 52E4 D9F5 7808
  -------------------------------------------------

 	"In every respect, vegans appear to enjoy equal
 	 or better health in comparison to both vegetarians
 	 and non-vegetarians."
 		-- T. Colin Campbell,
 		PhD Professor of Nutrition, Cornell University

Re: [[ -f file* ]]

[Frank Terbeck]

Matt Wozniski <godlygeek@gmail.com>:
> On Mon, May 18, 2009 at 5:14 AM, Atom Smasher wrote:
> > if i want to test for the presence of one or more files matching a certain
> > pattern, it seems non-trivial to do it with the normal "test" or conditional
> > expressions.
> ...
> > is there a better way?
> 
> Well, off the top of my head, I can think of
> 
> [ -n "$(print -- test*(N))" ]
> 
> but even that seems inelegant; I'm sure someone can chime in with
> something better.

How about this:

[snip]
set -- test*(N)
(( $# > 0 ))
[snap]

Regards, Frank

-- 
In protocol design, perfection has been reached not when there is
nothing left to add, but when there is nothing left to take away.
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