--- David Romano
<[EMAIL PROTECTED]> wrote:
> chen li wrote on Thu, Sep 07, 2006 at 01:13:04PM
> PDT:
> >
> > > One more question what if I have a file that
> have
> > > > different lines 1) some lines have number only
> 2)
> > > some
> > > > lines have more than 2 words at the begining?
> > > >
> > > > my $line1='1 1 1 1 1';
> > > > my $line2='group A 2 2 2 2";
> > > > my $line3= 'group B and C 3 3 3 3";
> > > >
> > > > Do you think I need a if statement to do the
> job?
> > >
> > > If you want to use a regex for all these, the
> > > following might work with
> > > your data:
> > > use strict;
> > > use warnings;
> > >
> > > $"=',';
> > > for (<DATA>) {
> > > my @data = m/(\D+[^\d\s]|\d+)/g;
> > > print "@data\n";
> > > }
> > >
> > > __DATA__
> > > 1 1 1 1 1
> > > group A 2 2 2 2
> > > group B and C 3 3 3 3
> >
> > Thank you for the lines. But what are the meaning
> for
> > 1) $"=',';
> This is the separator between array elements that
> are double-quote
> interpolated. See perldoc perlvar. Basically, if you
> interpolate an
> array (e.g., @data) in a string (e.g., "@data"), the
> default separator
> is a single space. You can change that to any
> character you want.
> Usually it's best to say:
>
> local $"='whatever';
>
> so that any interpolation outside the current block
> won't be affected.
>
> > 2) @data = m/(\D+[^\d\s]|\d+)/g;
> This is a regex which automatically uses whatever is
> in $_, and stores
> its matches into the @data array. The for loop
> automatically assigns
> $line1, $line2, and $line3 to $_ for each iteration
> of the for loop, and
> so m/.../g matches against the value in $_. The
> values (from your data)
> can either be more than one non-digit followed by a
> character that isn't
> a space and isn't a digit (the \D+[^\d\s] part) or
> more than one digit
> (the \d+) part. It matches greedily (the /g part ),
> and each match is
> returned when called in list context. For this case,
> it's stored in
> @data. Hope that helps, and try to keep the
> responses to the list,
> since then others can see the on-going discussion as
> well.
>
> - David
Thank you very much David!
One more question about this regex:
@data = m/(\D+[^\d\s]|\d+)/g;
I check Programming Perl or perldoc they say ^ is used
as an anchor meaning "start/begining with". But here
looks like it has a different usage. Is that right?
Li
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