builtin regular expressions?

[Mirco Wahab]

Thus spoke Jorge Godoy (on 2006-09-30 19:04):
> Mirco Wahab <wahab at chemie.uni-halle.de> writes:
>>   sub print_message {
>>      if   (/^track="(.+?)"/ ){ print "Your track is $1\n" }
>>      ...
> 
> Specially the non-greedy part. :-) I don't believe that non-greedyness would
> be adequate here since I believe he's willing to process the whole line.

Ohh, but I think it really is, my intention was
to get the quotet text out of the quotes, if
there is any, eg.:


   sub print_message {
      if   (/^track="(.+?)"/ ){ print "Your track is $1\n" }
      ...
   }

   print_message for 'track="My favorite track"', 'title="My favorite song"',
                     'artist="Those Dudes"', 'Something else' ;

(... our quoting chars are just inverted.)

> $line = "track='My favorite track'";
> if ($line =~ /^track=(.+?)/) { print "My track is $1\n"};
> 
> outputs
> My track is '

Of course, you can't have the nongreedy thing
without a following item, in the case mentioned,
a second \" (which would have been consumed
in the 'greedy' mode).

> and what I'd use
> 
> $line = "track='My favorite track'";
> if ($line =~ /^track=(.*)/) { print "My track is $1\n"};

OK, but to pull the quoted text alone, you'd
need the non-greedy thing, as in

   ...
   if   ( /^track='(.+?)'/ ){ print "Your track is $1\n" }
   ...

Alternatively, you could use the negated character class
for that:

  if   ( /^track='([^']+)/ ){ print "Your track is $1\n" }

which has exactly the same character count (so taste matters here) ...

Regards

Mirco