Perl WANNABE wrote:
* John W. Krahn <[EMAIL PROTECTED]> [2008-06-27 11:28]:
Tim Bowden wrote:
On Tue, 2008-06-24 at 19:37 -0700, John W. Krahn wrote:
Perhaps:
my ( $snippet ) = $string =~ /\w\["([^"]+)",/;
$string =~ /\w\["([^"]+)",/;
my $snippet = $1;
does the trick. I can see If I don't get on top of regex's I'm
seriously restricting the power of perl. Starting to understand
them better now.
You shouldn't do that. If you use the value of a numeric variable
without verifying that the regexp matched successfully then the
value in the numeric variable could be the result of a previous
successful match.
That's a GREAT point John but how can you verify that the regexp
matched successfully ?
Using the previous example:
my $snippet;
if ( $string =~ /\w\["([^"]+)",/ ) {
$snippet = $1;
}
Or:
$string =~ /\w\["([^"]+)",/ and my $snippet = $1;
Or:
my ( $snippet ) = $string =~ /\w\["([^"]+)",/;
How do you know that the $1 does NOT come from your last regexp, you
can't undefine it BEFORE you use it ?
No, numeric variable are read-only and cannot be modified outside of a
regular expression.
John
--
Perl isn't a toolbox, but a small machine shop where you
can special-order certain sorts of tools at low cost and
in short order. -- Larry Wall
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