Searching Stings with Arrays?

basic · December 20, 2006, 11:06pm

Hi, I’ve been having a little problem with this. most of my ruby is from
rails and both are shaky.

okay what I’ve got is a string (which is a browser user agent) and I
would like to search that string with a predefined array of browsers.
I’ve done this in php so I’m positve an easy solution exists in Ruby

this is what I got
@string = “mozilla/5.0 (macintosh; u; ppc mac os x; en)
applewebkit/418.9.1 (khtml, like gecko) safari/419.3”

array = [“shiira”, “msie”, “safari”, “firefox”, “netscape”]

so I’d like to search the string for any matches, it should stop at
safari and bob’s sombodys uncle.

this is what I’ve been trying to do.
array.find {|b| b == @string}.to_s

this does’t work I know, but I’m I in the right direction?

basic · December 20, 2006, 11:16pm

Hi –

On Thu, 21 Dec 2006, Phil C. wrote:

array = [“shiira”, “msie”, “safari”, “firefox”, “netscape”]

so I’d like to search the string for any matches, it should stop at
safari and bob’s sombodys uncle.

this is what I’ve been trying to do.
array.find {|b| b == @string}.to_s

this does’t work I know, but I’m I in the right direction?

You could use:

@string.include?(b)

or, if you want to be more careful about false positives (like, if
“msie” was a substring in some other browser’s string), you could do:

array.find {|b| @string[/#{b}/] }

which anchors to word boundaries. (All untested, so check for typos
and/or logic errors

David

basic · December 20, 2006, 11:20pm

On 12/21/06, Phil C. [email protected] wrote:

this is what I got
@string = “mozilla/5.0 (macintosh; u; ppc mac os x; en)
applewebkit/418.9.1 (khtml, like gecko) safari/419.3”

array = [“shiira”, “msie”, “safari”, “firefox”, “netscape”]

so I’d like to search the string for any matches, it should stop at
safari and bob’s sombodys uncle.

array.find {|b| @string =~ /#{b}/}

Iterates over each entry of the array, makes a regexp of it (the
/#{b}/ bit) and matches that against the string. (Ideally, you want
@string =~ Regexp.escape(b), but with the strings you have it comes to
the same thing.)

martin

basic · December 20, 2006, 11:20pm

On 12/20/06, [email protected] [email protected] wrote:

I’ve done this in php so I’m positve an easy solution exists in Ruby
this is what I’ve been trying to do.

array.find {|b| @string[/#{b}/] }

which anchors to word boundaries. (All untested, so check for typos
and/or logic errors

Reminds me of Knuth’s great saying
Beware of this code, I have only proved it correct, I have never tried
it!
You’ll be allright

David

–
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A. RUBY FOR RAILS by David A. Black (Ruby for Rails)
aka The Ruby book for Rails developers!
Q. Where can I get Ruby/Rails on-site training, consulting, coaching?
A. Ruby Power and Light, LLC (http://www.rubypal.com)

R

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hasn’t started yet. Don’t be misled by the enormous flow of money into
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defacto standards for unsophisticated buyers using poor adaptations of
incomplete ideas.”

Alan Kay

basic · December 20, 2006, 11:28pm

You’ll probably have 10 (better) answers for this by the time I’ve
posted, but here’s mine:

a = “something is here”
b = [ ‘x’, ‘y’, ‘g’, ‘q’, ‘z’ ]
b.find { |c| Regexp.new( c ).match( a ) } => “g”

The regexp.new creates a new regex (surprise) like /c/, and then
searches for it in the string a. If it’s not found, match returns nil,
which is false, so find continues. If it’s found, match is an object,
which is true, so find exits with that item from the array.

this is what I’ve been trying to do.
array.find {|b| b == @string}.to_s
this does’t work I know, but I’m I in the right direction?

The find is on the right track, but what you’re saying is that the
array item must match the full string … which, based on your problem
description, is incorrect.

jz

basic · December 20, 2006, 11:32pm

Phil C. wrote:

This might get you started off on the right path:

m, agent = *@string.match(/(shiira|msie|safari|firefox|netscape)/)
p agent

outputs

safari

If you need further clarification of this code, just let me know.

Tom W.

basic · December 20, 2006, 11:40pm

William J. wrote:

I’ve done this in php so I’m positve an easy solution exists in Ruby
this is what I’ve been trying to do.

array.find {|b| @string[/#{b}/] }

which anchors to word boundaries.

Are you sure?

array.find{|s| @string[/\b#{s}\b/] }

We don’t need no stinkin’ loops:

p @string.split(/\W/) & array

basic · December 20, 2006, 11:34pm

[email protected] wrote:

array.find {|b| b == @string}.to_s
array.find {|b| @string[/#{b}/] }

which anchors to word boundaries.

Are you sure?

array.find{|s| @string[/\b#{s}\b/] }

basic · December 20, 2006, 11:50pm

[email protected] wrote:

rails and both are shaky.

@string.include?(b)
array.find{|s| @string[/\b#{s}\b/] }

Thanks. I had this weird feeling something was wrong when I sent that
message… I think the ‘b’ variable name fooled me

Yeah, that’s why I changed it to “s”.

basic · December 21, 2006, 2:35am

Hi –

On Thu, 21 Dec 2006, William J. wrote:

array.find{|s| @string[/\b#{s}\b/] }

We don’t need no stinkin’ loops:

p @string.split(/\W/) & array

To each his own I like the loop – though I’m not sure why I used
[] instead of just matching. I think I somehow had map on the brain.

David

basic · December 20, 2006, 11:44pm

Hi –

On Thu, 21 Dec 2006, William J. wrote:

I’ve done this in php so I’m positve an easy solution exists in Ruby
this is what I’ve been trying to do.

array.find {|b| @string[/#{b}/] }

which anchors to word boundaries.

Are you sure?

array.find{|s| @string[/\b#{s}\b/] }

Thanks. I had this weird feeling something was wrong when I sent that
message… I think the ‘b’ variable name fooled me

David

basic · December 25, 2006, 8:03pm

Tom W. wrote:

Phil C. wrote:

This might get you started off on the right path:
m, agent = *@string.match(/(shiira|msie|safari|firefox|netscape)/)
p agent
outputs
safari
If you need further clarification of this code, just let me know.

Tom W.

can I tag a regex on to this to pull the version of the browser? I
understand I might have to to break this down as some useragents are
differently setup.

basic · December 21, 2006, 10:05am

On Wed, 20 Dec 2006 22:06:49 -0000, Phil C.
[email protected]
wrote:

array = [“shiira”, “msie”, “safari”, “firefox”, “netscape”]

so I’d like to search the string for any matches, it should stop at
safari and bob’s sombodys uncle.

this is what I’ve been trying to do.
array.find {|b| b == @string}.to_s

this does’t work I know, but I’m I in the right direction?

You already have your answers it seems, so for completeness I’ll just
mention a recent ruby quiz:

http://rubyquiz.com/quiz103.html

It focused on larger word sets that you’re looking at, but it might give
you a different perspective on the problem.

basic · December 25, 2006, 11:10pm

Phil C. wrote:

safari
If you need further clarification of this code, just let me know.

Tom W.
can I tag a regex on to this to pull the version of the browser? I
understand I might have to to break this down as some useragents are
differently setup.

@string = “mozilla/5.0 (macintosh; u; ppc mac os x; en)
applewebkit/418.9.1 (khtml, like gecko) safari/419.3”

array = [“shiira”, “msie”, “safari”, “firefox”, “netscape”]

@string =~ %r{(#{ array.map{|s| Regexp.escape(s)}.join(’|’)})/(\S+)}
p $1,$2

browser,version = @string.match(
%r{(#{ array.map{|s| Regexp.escape(s)}.join(’|’)})/(\S+)}).
captures
p browser,version