On Aug 25, 7:01 am, jwkr...@shaw.ca ("John W. Krahn") wrote:
> Honza Mach wrote:
> > Hi everybody,
>
> Hello,
>
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> > I was wondering, if it is possible to use backreferences in the pattern
> > repetition bracket operator.
>
> > Consider the following string:
>
> > my $string = "5 abcdefghijklmn";
>
> > The number five at the beginning of the string means, that I want to
> > extract first five characters from the latter part of the string. I
> > tried the following code, but it doesn`t work:
>
> > $string =~ s/(\d+)\s+(.{\g1})//;
> > print "extracted: $1 $2\n";
>
> > The desired output would be:
>
> > extracted: 5 abcde
>
> > It seems, that it is not possible to use backreferences within the
> > bracket operator (or am I doing something wrong?).
>
> > Is there other solution to my problem.
>
> If it always involves a single digit followed by a single space you
> could use unpack()
>
> $ perl -le'
> my $string = "5 abcdefghijklmn";
> my ( $num, $extract ) = unpack "A2 X2 A2/a*", $string;
> print "$num $extract";
> '
> 5 abcde
>Or, eliminating the single digit requirement with split/substr: ( $num, $ss ) = split " ", $string; print "$num ", substr $ss, 0 , $num; -- Charles DeRykus -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
