# Reg Ex **URL:** \ **Category:** Ruby\ **Created:** [September 7, 2007, 12:58am UTC](https://www.ruby-forum.com/t/reg-ex/114003 "2007-09-07T00:58:28Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![animate123](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/e19b73/32.png) [@animate123](https://www.ruby-forum.com/u/animate123)\ **Post date:** [September 7, 2007, 12:58am UTC](https://www.ruby-forum.com/t/reg-ex/114003/1 "2007-09-07T00:58:28Z")
I’m querying through the .com’s looking for any www name with Cisco in it. I’m using a reg exp that is reading a file line by line obtained by Verisign that has all the domain names with a .com extension. Here is my reg exp: file.each { |line| print line if line =~ /(C|c)isco|CISCO/ } but I’m getting results like SanFrancisco and Francisco. Does anyone know how I can modify my reg exp to not include certain keywords like SanFrancisco and Francisco? -Chuck ---
**Author:** ![animate123](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/e19b73/32.png) [@animate123](https://www.ruby-forum.com/u/animate123)\ **Post date:** [September 7, 2007, 1:14am UTC](https://www.ruby-forum.com/t/reg-ex/114003/2 "2007-09-07T01:14:34Z")
On Sep 7, 2007, at 12:58 AM, Charles P. wrote: > Does anyone know how I can modify my reg exp to not include certain > keywords like SanFrancisco and Francisco? You need to assert word boundaries: /\b((C|c)isco|CISCO)\b/ – fxn ---
**Author:** ![animate123](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/e19b73/32.png) [@animate123](https://www.ruby-forum.com/u/animate123)\ **Post date:** [September 7, 2007, 1:11am UTC](https://www.ruby-forum.com/t/reg-ex/114003/3 "2007-09-07T01:11:33Z")
Hi I don’t know if you need to check the caps, but your regex could be /cisco/i (the i is for case insensitive) To “ban” certain words, you’ could use lookaround expression -and I don’t know if Ruby supports it-, but I personally find cleaner check programatically against a list, and add the “exceptions” to that list. Hope it helps 🙂 Diego. ---
**Author:** ![animate123](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/e19b73/32.png) [@animate123](https://www.ruby-forum.com/u/animate123)\ **Post date:** [September 7, 2007, 10:42am UTC](https://www.ruby-forum.com/t/reg-ex/114003/4 "2007-09-07T10:42:15Z")
The boundaries could be a good idea, but if he needs urls like [ciscosystems.com](http://ciscosystems.com), with the final \b won’t match. Keep that in sight 🙂 ---
**Author:** ![animate123](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/e19b73/32.png) [@animate123](https://www.ruby-forum.com/u/animate123)\ **Post date:** [September 7, 2007, 11:54am UTC](https://www.ruby-forum.com/t/reg-ex/114003/5 "2007-09-07T11:54:29Z")
2007/9/7, Diego S. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid): > > How about: > > /\b([Cc]isco|CISCO)\b/ > > > > or even > > > > /\bcisco\b/i I’d probably use a second rx like file.each { |line| print line if line =~ /\bcisco/i && line !~ /sanfrancisco/i} Kind regards robert ---
**Author:** ![animate123](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/e19b73/32.png) [@animate123](https://www.ruby-forum.com/u/animate123)\ **Post date:** [September 7, 2007, 2:06am UTC](https://www.ruby-forum.com/t/reg-ex/114003/6 "2007-09-07T02:06:36Z")
On Fri, 7 Sep 2007, Charles P. wrote: > file.each { |line| print line if line =~ /(C|c)isco|CISCO/ } > … > Does anyone know how I can modify my reg exp to not include > certain keywords like SanFrancisco and Francisco? How about: /\b([Cc]isco|CISCO)\b/ or even /\bcisco\b/i ? ---
**Author:** ![animate123](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/e19b73/32.png) [@animate123](https://www.ruby-forum.com/u/animate123)\ **Post date:** [September 7, 2007, 6:26pm UTC](https://www.ruby-forum.com/t/reg-ex/114003/7 "2007-09-07T18:26:47Z")
> Posted by Charles P. (chuckdawit) on 07.09.2007 00:58 > I’m querying through the .com’s looking for any www name with Cisco in it. > I’m using a reg exp that is reading a file line by line obtained by > Verisign that has all the domain names with a .com extension. > Here is my reg exp: > > file.each { |line| print line if line =~ /(C|c)isco|CISCO/ } > > but I’m getting results like SanFrancisco and Francisco. > > Does anyone know how I can modify my reg exp to not include certain > keywords like SanFrancisco and Francisco? > > -Chuck > Reply with quote Maybe also try something like: print line if line =~ /^(?!._(?:SanFrancisco|Francisco))._\Bcisco/i Cheers j.k. ---
**Author:** ![animate123](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/e19b73/32.png) [@animate123](https://www.ruby-forum.com/u/animate123)\ **Post date:** [September 7, 2007, 8:27pm UTC](https://www.ruby-forum.com/t/reg-ex/114003/8 "2007-09-07T20:27:32Z")
On Sep 6, 4:58 pm, Charles P. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Does anyone know how I can modify my reg exp to not include certain > keywords like SanFrancisco and Francisco? Instead of modifying the regex, how about simply working on the data until it’s right? ACCEPTABLE = [/francisco/i, /scisco/i] matches = file.readlines.select{ |line| line =~ /[Cc]isco|CISCO/ } ACCEPTABLE.each{ |re| matches.delete\_if{ |line| line =~ re } } puts matches ---
**Author:** ![animate123](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/e19b73/32.png) [@animate123](https://www.ruby-forum.com/u/animate123)\ **Post date:** [September 11, 2007, 11:42pm UTC](https://www.ruby-forum.com/t/reg-ex/114003/9 "2007-09-11T23:42:27Z")
Gavin K. wrote: > On Sep 6, 4:58 pm, Charles P. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > > Does anyone know how I can modify my reg exp to not include certain > > keywords like SanFrancisco and Francisco? > > Instead of modifying the regex, how about simply working on the data > until it’s right? > > ACCEPTABLE = [/francisco/i, /scisco/i] > matches = file.readlines.select{ |line| line =~ /[Cc]isco|CISCO/ } > ACCEPTABLE.each{ |re| matches.delete\_if{ |line| line =~ re } } > puts matches If I want to print the line to a new file I use this: dnsfile.each { |line| newfile.puts line if line =~ /(\b((C|c)isco|CISCO)\b) / what can I do if I want to print it to a newfile and print it to the screen at the same time?