Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

I have a loop where I want to check that a certain word is not part of my URLs. But I am having problems with the part where I am trying to make sure my search ignores anything with three specific words in it. For example If a URL has a word called "longwordOne" in it then I dont want it part of my loop search. Here is part of what I have tried: 
#words I dont want to be part of my loop search:
$wordOne = 'longwordOne';
$wordTwo = 'anotherLongWord';
$wordThree = 'thirdLongHere';

#loop search here
next if ($_ =~ /(?:$wordOne|$wordTwo|$wordThree)/gi);

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Replies are listed 'Best First'.
Re: next if attempt
by dreadpiratepeter (Priest) on Jul 16, 2003 at 12:57 UTC
    What is your exact issue. I find nothing wrong with the code (besides being needlessly verbose and containing an unneeded /g, see below). The regexp should work as far as I can see. Indeed, it works find on this test program:
    
use strict;

my $wordOne = 'longwordOne';
my $wordTwo = 'anotherLongWord';
my $wordThree = 'thirdLongHere';

while (<DATA>) {
next if ($_ =~ /(?:$wordOne|$wordTwo|$wordThree)/gi);

  print ;

}

exit;


__DATA__
blah blah longwordOne blah
blow
blow
blee anotherLongWord glgl
thirdLongHere
fddsf ds sdfs fs fsd
  fggh hg longwordOne
sdasd

    [download]

    I get:
    blow
blow
fddsf ds sdfs fs fsd
sdasd

    [download]
    and the next can be written more succinctly as: 
    next if /$wordOne|$wordTwo|$wordThree/i;

    [download]


    -pete
    "Worry is like a rocking chair. It gives you something to do, but it doesn't get you anywhere."
[reply]
[d/l]
[select]

      To make it a bit easier to update, one might write it as:

      my @stopwords = qw( longwordOne anotherLongWord thirdLongHere );
my $stopmatch = join( '|', @stopwords );

while( <DATA> ) {
    next if /$stopmatch/i;
    print;
}

      [download]

      Thus you only have to update the @stopwords array to add another stop-word.

      --
      "To err is human, but to really foul things up you need a computer." --Paul Ehrlich

[reply]
[d/l]
[select]

        and to make it more accurate, one might write it as (untested:)

        my @stopwords= qw/ car pet carpet /;
my $stopmatch= join '|' => 
  map { '\b' . $_[1] . '\b' } ## match full words
  reverse sort { $a->[0] <=> $b->[0] } ## longest first
  map { [length $_, $_] } @stopwords;

        [download]

        Thus longer words will match first, and only full words will be matched.

        ~Particle *accelerates*

[reply]
[d/l]

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