Re: Regular expressions

use Data::Dumper;
my $string = "sp Hello there sp \n Hey hey sp How are you? sp";
my @result = $string =~ m<
    [ ]?  # optional space
    sp    # literal 'sp'
    [ ]?  # optional space
    (.*?) # non-greedy capture
    [ ]?  # optional space
    sp    # literal 'sp'
    [ ]?  # optional space
>xg;
print Dumper(\@result);

__output__

$VAR1 = [
          'Hello there',
          'How are you?'
        ];
[download]

That code does the trick, although you may want to make it more generic if you're working on more complex strings. Also checkout using split() if possible.
HTH

_________ broquaint

Comment on Re: Regular expressions Download Code

Replies are listed 'Best First'.
Re: Re: Regular expressions by aersoy (Scribe) on Jun 24, 2002 at 13:05 UTC
Hello, I think your Regular Expression is unnecessarily complex. Besides it chokes on a string like this: "sp Hello there! spelling spoiler spooky asp wizard! sp \n Hey hey sp How are you? sp". A simpler and better solution would be `@result = split /\bsp\b/, $string;` [download] (where b is for boundary) -- Alper Ersoy	[reply] [d/l]
Re: Re: Re: Regular expressions by broquaint (Abbot) on Jun 24, 2002 at 13:21 UTC
I think your Regular Expression is unnecessarily complex. Indeed it is, but it does give the specified output in the root node. Besides it chokes on a string like this: "sp Hello there! spelling spoiler spooky asp wizard! sp \n Hey hey sp How are you? sp". Unfortunately so which is why I recommended it to be made more generic (i.e not rely on space being around 'sp'). A simpler and better solution would be That would be nice but unfortunately it gives this incorrect output `$VAR1 = [ '', ' Hello there ', ' Hey hey ', ' How are you? ' ];` [download] As outlined below it's splitting the string on 'sp' as opposed to grabbing the text between it (as though the first 'sp' were a `<sp>` and the second a `</sp>` and so on) `01 2 3 sp Hello there sp \n Hey hey sp How are you? sp` [download] `_________ broquaint`	[reply] [d/l] [select]
Re: Re: Re: Re: Regular expressions by aersoy (Scribe) on Jun 24, 2002 at 13:48 UTC
That would be nice but unfortunately it gives this incorrect output You are right, I recognized that too, after posting. But there are many ways to trim the leading and following white space characters from a string. ie. `map { s/^\s\|\s$//g } @result;` would do the trick. -- Alper Ersoy	[reply] [d/l]
Re: Re: Regular expressions by kidd (Curate) on Jun 24, 2002 at 12:53 UTC
Thanks for your reply, that works great...	[reply]