Re: string manipulation : removing a part of a string

[Vincent Torri]

On Mon, 18 Jun 2012, Eric Blake wrote:

> On 06/18/2012 09:40 AM, Vincent Torri wrote:
>
> > > But you can still be shorter than using a pushdef:
> > >
> > > option=m4_bpatsubst([[$2]], [^-Wno-], [-W])
> >
> > does not work. Removing ^ seems to work
>
> Oh, right.  That's due to the necessity of double-quoting $2 introducing
> extra characters to be matched by the regex.  Omitting the anchor means
> that you will match -Wno- wherever it appears (even in
> -fsome-Wno-option); and if you are worried about that being a real
> possibility, then you can restore the anchoring effect by taking into
> account the double-qouting, and all without unbalancing [], by the use
> of the . regex:
>
> option=m4_bpatsubst([[$2]], [^\(.\)-Wno-], [\1-W])
>
> But you are probably right that you don't have to worry about -Wno-
> appearing anywhere but the beginning, in which case omitting the anchor
> is indeed simplest.

yes. having -Wno- not at the beginning is not a problem :)

thank you for your help

Vincent Torri