# Create a string from a pattern?

**URL:** <https://www.ruby-forum.com/t/create-a-string-from-a-pattern/109102>\
**Category:** Ruby\
**Created:** [July 11, 2007, 3:29pm UTC](https://www.ruby-forum.com/t/create-a-string-from-a-pattern/109102 "2007-07-11T15:29:48Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![prichard](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/90db22/32.png) [@prichard](https://www.ruby-forum.com/u/prichard)\
**Post date:** [July 11, 2007, 3:29pm UTC](https://www.ruby-forum.com/t/create-a-string-from-a-pattern/109102/1 "2007-07-11T15:29:48Z")

</div>

Im trying to come up with an easy way to generate a random string,  
based on a supplied pattern, maybe something like:

String.from\_pattern("\d\d\d@\w{3,5}.com") =\> “removed\_email\_address@domain.invalid”

Ive used a standard reg exp format here, but it doesnt matter if it  
uses something else.  
Any simple way to do this?

Thanks  
Paul

---

<div class="post-metadata">

**Author:** ![prichard](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/90db22/32.png) [@prichard](https://www.ruby-forum.com/u/prichard)\
**Post date:** [July 11, 2007, 3:33pm UTC](https://www.ruby-forum.com/t/create-a-string-from-a-pattern/109102/2 "2007-07-11T15:33:49Z")

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On 09.07.2007 17:41, Paul R. wrote:

> Im trying to come up with an easy way to generate a random string,  
> based on a supplied pattern, maybe something like:
> 
> String.from\_pattern("\d\d\d@\w{3,5}.com") =\> “removed\_email\_address@domain.invalid”
> 
> Ive used a standard reg exp format here, but it doesnt matter if it  
> uses something else.  
> Any simple way to do this?

Dunno whether you’d count this as simple:

“%d-%d{3}-%w{3,5}”.gsub /%(.)(?:{(\d+)(?:,(\d+))?})?/ do |m|  
t, mi, ma = $1, $2, $3

rep = case  
when mi.nil?  
1  
when ma.nil?  
mi.to\_i  
else  
mi.to\_i + rand(1 + ma.to\_i - mi.to\_i)  
end

case t  
when “d”  
rep.to\_enum(:times).inject("") {|s,| s \<\< (?0 + rand(10)).chr}  
when “w”  
rep.to\_enum(:times).inject("") {|s,| s \<\< (?a + rand(1 + ?z -  
?a)).chr}  
else  
# ignore  
m  
end  
end

Kind regards

robert

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<div class="post-metadata">

**Author:** ![prichard](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/90db22/32.png) [@prichard](https://www.ruby-forum.com/u/prichard)\
**Post date:** [September 25, 2007, 11:04pm UTC](https://www.ruby-forum.com/t/create-a-string-from-a-pattern/109102/3 "2007-09-25T23:04:27Z")

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On Jul 9, 10:25 am, Robert K. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> ```
> else
> # ignore
> m
> 
> ```
> 
> end  
> end
> 
> Kind regards
> 
> ```
> robert
> 
> ```

its more elegant than I had, not sure about simpler 😉  
I had to do this ( just in case any one else tries it )  
require ‘enumerator’

Thanks!  
Paul

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<div class="post-metadata">

**Author:** ![prichard](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/90db22/32.png) [@prichard](https://www.ruby-forum.com/u/prichard)\
**Post date:** [July 11, 2007, 4:19pm UTC](https://www.ruby-forum.com/t/create-a-string-from-a-pattern/109102/4 "2007-07-11T16:19:59Z")

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am fairly new to ruby so please help me. I am getting the  
“gem\_orginal\_require” error.  
Here is what I have.  
The following gems installed:

\*\*\* LOCAL GEMS \*\*\*  
activerecord (1.15.3)  
Implements the ActiveRecord pattern for ORM.  
activesupport (1.4.2)  
Support and utility classes used by the Rails framework.  
fastthread (1.0)  
Optimized replacement for thread.rb primitives  
hoe (1.2.1)  
Hoe is a way to write Rakefiles much easier and cleaner.  
hpricot (0.6)  
a swift, liberal HTML parser with a fantastic library  
mechanize (0.6.9)  
Mechanize provides automated web-browsing  
rake (0.7.3)  
Ruby based make-like utility.  
rubyforge (0.4.2)  
A simplistic script which automates a limited set of rubyforge  
operations  
scrubyt (0.3.0)  
A powerful Web-scraping framework  
sources (0.0.1)  
This package provides download sources for remote gem installatio

The version of ruby installed: ruby 1.8.6 (2007-03-13 patchlevel 0)  
[i686-linux]

And here is the script I am trying to run

#!/usr/bin/ruby

require ‘rubygems’  
require ‘scrubyt’

google\_data = Scrubyt::Extractor.define do  
fetch ‘[Google](http://www.google.com/ncr)’  
fill\_textfield ‘q’, ‘ruby’  
submit

result ‘Ruby P.ming Language’  
end

google\_data.to\_xml.write($stdout, 1)  
Scrubyt::ResultDumper.print\_statistics(google\_data)

And finally the errors I get:  
/usr/lib/ruby/site\_ruby/1.8/rubygems/custom\_require.rb:27:in  
`gem_original_require': no such file to load -- parse_tree_reloaded (LoadError) from /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `require’  
from /usr/lib/ruby/gems/1.8/gems/scrubyt-0.3.0/lib/scrubyt.rb:9  
from  
/usr/lib/ruby/site\_ruby/1.8/rubygems/custom\_require.rb:32:in  
`gem_original_require' from /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:32:in `require’  
from ./test.rb:4

Any help would be appreciated.