From: Gavin Kistner <gavin@...>
Date: 2005-09-05T09:26:48+09:00
Subject: Re: Making my Regex less greedy?

On Sep 4, 2005, at 5:51 PM, luke wrote:
> The logic I'd like the above regex to operate with is: "Starting 100
> characters into the message, chop the message at the next paragraph  
> break".

The question mark makes quantifiers non-greedy.
.+ versus .+?
.* versus .*?
.{a,b} versus .{a,b}?

For example:
txt = <<END
Twas brillig
and the slithy toves
did gyre and gimble
in the wabe
END

def truncate_after( str, length )
     str =~ /\A(.{#{length},}?)\n(.+)/m
     return [ $1, $2 ]
end

p truncate_after( txt, 0 )
#=>["Twas brillig", "and the slithy toves\ndid gyre and gimble\nin  
the wabe\n"]

p truncate_after( txt, 20 )
#=>["Twas brillig\nand the slithy toves", "did gyre and gimble\nin  
the wabe\n"]

p truncate_after( txt, 40 )
#=>["Twas brillig\nand the slithy toves\ndid gyre and gimble", "in  
the wabe\n"]