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From: Rakesh Sharma on 3 Apr 2010 20:32
Hi,

I want to match a string of numbers followed optionally by either a +
or a -.
The corner cases are: the number cannot begin with a 0 unless it's a
solitary 0.

So expressing this in terms of regular expressions I can write:

[0][+-]? | [1-9][0-9]*[+-]?

So far so good, but how would I write the equivalent functionality in
terms
of shell file patterns of the kind found in the 'case'..'esac'
statments of bourne shell?

Thanks


-- Rakesh
From: marty.mcgowan on 3 Apr 2010 20:48
On Apr 3, 8:32 pm, Rakesh Sharma <sharma...(a)hotmail.com> wrote:
> Hi,
>
> I want to match a string of numbers followed optionally by either a +
> or a -.
> The corner cases are: the number cannot begin with a 0 unless it's a
> solitary 0.
>
> So expressing this in terms of regular expressions I can write:
>
>     [0][+-]? | [1-9][0-9]*[+-]?
>
> So far so good, but how would I write the equivalent functionality in
> terms
> of shell file patterns of the kind found in the 'case'..'esac'
> statments of bourne shell?
>
> Thanks
>
> -- Rakesh

does this do it in bourne; i'm using bash:

case $1 in
0[+-]|[1-9][0-9]*[+-]) echo pattern -- $1;;
*) echo NOT a match: $1;;
esac

-=+-- Marty McG
From: Rakesh Sharma on 3 Apr 2010 20:57
On Apr 4, 5:48 am, "marty.mcgo...(a)gmail.com" <marty.mcgo...(a)gmail.com>
wrote:
> On Apr 3, 8:32 pm, Rakesh Sharma <sharma...(a)hotmail.com> wrote:
>
>
>
> > Hi,
>
> > I want to match a string of numbers followed optionally by either a +
> > or a -.
> > The corner cases are: the number cannot begin with a 0 unless it's a
> > solitary 0.
>
> > So expressing this in terms of regular expressions I can write:
>
> >     [0][+-]? | [1-9][0-9]*[+-]?
>
> > So far so good, but how would I write the equivalent functionality in
> > terms
> > of shell file patterns of the kind found in the 'case'..'esac'
> > statments of bourne shell?
>
> > Thanks
>
> > -- Rakesh
>
> does this do it in bourne; i'm using bash:
>
> case $1 in
> 0[+-]|[1-9][0-9]*[+-]) echo pattern --  $1;;
> *)     echo NOT a match: $1;;
> esac
>
> -=+-- Marty McG


No, this does not work under the bourne shell. What I need is the
filename wildcards to accomplish
this thingy.

Regards,
-- Rakesh
From: Seebs on 3 Apr 2010 22:05
On 2010-04-04, Rakesh Sharma <sharma__r(a)hotmail.com> wrote:
> So far so good, but how would I write the equivalent functionality in
> terms
> of shell file patterns of the kind found in the 'case'..'esac'
> statments of bourne shell?

You can't. Shell patterns don't have a way to express repetition of
anything other than "any character".

-s
--
Copyright 2010, all wrongs reversed. Peter Seebach / usenet-nospam(a)seebs.net
http://www.seebs.net/log/ <-- lawsuits, religion, and funny pictures
http://en.wikipedia.org/wiki/Fair_Game_(Scientology) <-- get educated!
From: Ben Bacarisse on 3 Apr 2010 22:14
Rakesh Sharma <sharma__r(a)hotmail.com> writes:

> I want to match a string of numbers followed optionally by either a +
> or a -.
> The corner cases are: the number cannot begin with a 0 unless it's a
> solitary 0.
>
> So expressing this in terms of regular expressions I can write:
>
> [0][+-]? | [1-9][0-9]*[+-]?

[0] is little odd! You can make the ending more clear by re-writing
this as:

(0|[1-9][0-9]*)[+-]?

> So far so good, but how would I write the equivalent functionality in
> terms
> of shell file patterns of the kind found in the 'case'..'esac'
> statments of bourne shell?

bash can but not a POSIX shell. You can get close if can limit the
number of digits by simply writing out all the cases, but you can't
even use [0-9] (you need [0123456789] instead) so the end result will
be horrid and error prone.

--
Ben.
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