Reg Exp

[Dipesh Batheja]

Can somebody hep me with a very simple regular expression. I want to
write an regex which if matches a specific string should return false.
for example:
if i have string "Hello world", and i want to say, if you find "hello"
in this string then return false. Can someone explain how to write this?

 

[Jesús Gabriel y Galán]

Can somebody hep me with a very simple regular expression. I want to
write an regex which if matches a specific string should return false.
for example:
if i have string "Hello world", and i want to say, if you find "hello"
in this string then return false. Can someone explain how to write this?

Simple approach:

irb(main):007:0> a = "hello world"
=> "hello world"
irb(main):008:0> !(a =~ /hello/)
=> false
irb(main):009:0> !(a =~ /asdfsdf/)
=> true

Jesus.

 

[Dipesh Batheja]

Problem is i have function, which takes a regex as the parameter. I want
to pass this regex in such a way that the function returns false if the
string is matched and true if it isn't. I want the regex itself specify
that if it matches the given string then it is false otherwise true.

 

[Jeff Schoolcraft]

[Note: parts of this message were removed to make it a legal post.]

I'm not sure what you're going to gain from a regex if it's a specific
string and not a pattern.

irb(main):001:0> a = "Hello World"
=> "Hello World"
irb(main):002:0> !(a.include? 'Hello')
=> false
irb(main):003:0>

It seems you'd want to wrap that into a method to make the intent a little
more obvious

irb(main):011:0> def should_filter?(source, word)
irb(main):012:1> source.include? word
irb(main):013:1> end
=> nil
irb(main):014:0> should_filter?(a, 'Hello')

Just a thought.

to make the regex work as in your example though, you'd do this:
irb(main):021:0> !(a =~ /hello/i)
=> false

(case insensitive matching)

 

[Dipesh Batheja]

Ok let me try explain my situation a little bit.
I have default route in ROR environment.rb:
map.connect ':lang/:canonic/:controller/:action/:id

it matches paths like:
http://www.abc.com/en/acme/products/show/1

where :canonic is "acme" in this example

I have a specific case where :canonic cannot be "admin"

map.connect method take a key :requirements where I can specify a regex:
map.connect ':lang/:canonic/:controller/:action/:id, :requirement =>
{:canonic => /regex/ }

I need to write in the reg ex, in such a way, so that when something
like:

http://www.abc.com/en/admin/products/show/1

comes, it doesn't match the path.


I hope this helps in explaining my situation.

 

[Jeff Schoolcraft]

I don't think you'll be able to do what you want with just a regex pattern.
The closest you could get is negative lookahead. You'd have to pull out th=
e
first character and use negative lookahead for the rest, it will probably
only work for simple strings.

irb(main):029:0> a =3D "Hello World"
=3D> "Hello World"
irb(main):030:0> a =3D~ /h(?!ello)/i
=3D> nil
irb(main):031:0> b =3D "Hel l o world"
=3D> "Hel l o world"
irb(main):032:0> b =3D~ /h(?!ello)/i
=3D> 0

 

[Kyle]

Match the route with /admin/ in the path first.

map.connect ':lang/admin/:controller/:action/:id

If it's matched, it won't go on and try to match the route that you
showed us.

This is really a RoR question.

-Kyle

 

[fedzor]

Can somebody hep me with a very simple regular expression. I want to
write an regex which if matches a specific string should return false.
for example:
if i have string "Hello world", and i want to say, if you find "hello"
in this string then return false. Can someone explain how to write
this?

use the TextualRegexp gem

-------------------------------------------------------|
~ Ari
Careful - I'm like Stallman with katanas!

 

[David A. Black]

Hi --

Match the route with /admin/ in the path first.

map.connect ':lang/admin/:controller/:action/:id

If it's matched, it won't go on and try to match the route that you
showed us.

This is really a RoR question.

No, just an RoR answer


David

--
Rails training from David A. Black and Ruby Power and Light:
INTRO TO RAILS June 9-12 Berlin
ADVANCING WITH RAILS June 16-19 Berlin
INTRO TO RAILS June 24-27 London (Skills Matter)
See http://www.rubypal.com for details and updates!