# Regexp question for doing "and" searches

**URL:** <https://www.ruby-forum.com/t/regexp-question-for-doing-and-searches/100809>\
**Category:** Ruby\
**Created:** [February 3, 2006, 10:37pm UTC](https://www.ruby-forum.com/t/regexp-question-for-doing-and-searches/100809 "2006-02-03T22:37:54Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![jeff](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/e19b73/32.png) [@jeff](https://www.ruby-forum.com/u/jeff)\
**Post date:** [February 3, 2006, 10:37pm UTC](https://www.ruby-forum.com/t/regexp-question-for-doing-and-searches/100809/1 "2006-02-03T22:37:54Z")

</div>

Just can’t quite figure this one out.

Given a search phrase like “one two three”, I want to search a list of  
text strings for onex that contain ALL of those words, but not  
necessarily in that order.

The hard part for me is the “not necessarily in that order”.

Using ‘\b(one|two|three)\b’ will match if at least one of them occurs in  
any order, but I need all of them to match _and_ be in any order.

two one three =\> match  
one three =\> does not match

Any ideas? Is this possible with regular expressions?

Thanks!  
Jeff

---

<div class="post-metadata">

**Author:** ![jeff](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/e19b73/32.png) [@jeff](https://www.ruby-forum.com/u/jeff)\
**Post date:** [February 3, 2006, 11:03pm UTC](https://www.ruby-forum.com/t/regexp-question-for-doing-and-searches/100809/2 "2006-02-03T23:03:29Z")

</div>

On Sat, 4 Feb 2006 06:38:12 +0900, Jeff C. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
wrote:

> Just can’t quite figure this one out.
> 
> Given a search phrase like “one two three”, I want to search a list of  
> text strings for onex that contain ALL of those words, but not  
> necessarily in that order.

You can use look-aheads to build a re that looks like:

/^(?=._\bone\b)(?=._\btwo\b)(?=.\*\bthree\b)/

ensuring a match only if all look-ahead assertions pass.

phrase = “one two three”  
re = %r/^#{phrase.split.map{|s|“(?=.\*\b#{s}\b)”}}/  
while DATA.gets  
print if ~re  
end  
**END**  
one two three YUP  
one three two YUP  
zone two three NOPE  
three and two and one YUP

regards,  
andrew

---

<div class="post-metadata">

**Author:** ![jeff](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/e19b73/32.png) [@jeff](https://www.ruby-forum.com/u/jeff)\
**Post date:** [February 3, 2006, 11:06pm UTC](https://www.ruby-forum.com/t/regexp-question-for-doing-and-searches/100809/3 "2006-02-03T23:06:31Z")

</div>

Jeff C. wrote:

> two one three =\> match  
> one three =\> does not match

Seems to work:

s = “foo two bar three zap one”  
rx = /^(?=.\*one)(?=.\*two).\*three/m

p (rx =~ s)

s = “one three”  
p (rx =~ s)

Works like this too:  
rx = /^(?=.\*one)(?=.\*two)(?=.\*three)/m

---

<div class="post-metadata">

**Author:** ![jeff](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/e19b73/32.png) [@jeff](https://www.ruby-forum.com/u/jeff)\
**Post date:** [February 3, 2006, 11:07pm UTC](https://www.ruby-forum.com/t/regexp-question-for-doing-and-searches/100809/4 "2006-02-03T23:07:18Z")

</div>

Andrew J. wrote:

> You can use look-aheads to build a re that looks like:
> 
> /^(?=._\bone\b)(?=._\btwo\b)(?=.\*\bthree\b)/
> 
> ensuring a match only if all look-ahead assertions pass.

Awesome! I’ll give it a try.

Thanks a lot.  
Jeff

---

<div class="post-metadata">

**Author:** ![jeff](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/e19b73/32.png) [@jeff](https://www.ruby-forum.com/u/jeff)\
**Post date:** [February 3, 2006, 11:18pm UTC](https://www.ruby-forum.com/t/regexp-question-for-doing-and-searches/100809/5 "2006-02-03T23:18:43Z")

</div>

On Sat, 4 Feb 2006, Jeff C. wrote:

> two one three =\> match  
> one three =\> does not match
> 
> Any ideas? Is this possible with regular expressions?
> 
> Thanks!  
> Jeff

stupid - but works

```
 harp:~ > cat a.rb
 strings = <<-txt
   two one three
   one three
   one foo two bar three
   foo two bar one three
   two
 txt

 atoms = '\b(?:one|two|three)\b'
 re = %r/(?:#{ atoms }).*(?:#{ atoms }).*(?:#{ atoms })/

 require "yaml" and strings.each{|string| y string => (string =~ re 

```

? true : false)}

```
 harp:~ > ruby a.rb
 ---
 " two one three\n": true
 ---
 " one three\n": false
 ---
 " one foo two bar three\n": true
 ---
 " foo two bar one three\n": true
 ---
 " two\n": false

```

hth.

-a