How can specify multiple words must be present in a word. For eg. Find all sentences that has words "cat", "dog" and "birds" in any order.

So this pattern should match following sentences
All cats are neither dogs nor birds.
All birds are neither dogs nor cats.

But should not match following sentences.
  All cats are not dogs.
All birds are neither not cats.

Thanks
_DzDz

DizzieDazz,
  I'm far from an expert, so I COULD be wrong, but I don't think that there is an AND within the regular expression construct set. However, I took your examples, put them into a text file and wrote a vb.net app which successfully identifies the sentences containing cat, dog and bird. I used regular expression matching once for each word and used a boolean variable to identify the correct sentences. I will happily share the code with you. I can email the zipped app to you if you have vb.net or just copy the logic into a text file and send it to you or whatever works for you. Let me know here or at:
RWDelPorto@psu.edu

Ron DelPorto
Lecturer, Computer Science
Penn State Erie, The Behrend College

R. W. DelPorto

In perl you do:

#!/usr/bin/perl
#

while(<>) {
        next unless (/cat/ && /dog/ && /bird/) ;
        print;
}

---

test data
$ echo All cats are neither dogs nor birds | ./tmp.pl
All cats are neither dogs nor birds
$ echo All cats are neither dogs nor balloons | ./tmp.pl
$

HTH


--
Don't Stand on your head - you'll get footprints in your hair. http://www.charlieharvey.org.uk