variable $LAST_PAREN_MATCH

$+ の別名

require "English"

r1 = Regexp.compile("<img src=(http:.+?)>")
r2 = Regexp.compile("<a href=(http|ftp).+?>(.+?)</a>")

while line = DATA.gets
  [ r1, r2 ].each {|rep|
    rep =~ line
    p $+
  }
end
__END__
<tr> <td><img src=http://localhost/a.jpg></td> <td>ikkou</td> <td><a href=http://localhost/link.html>link</a></td> </tr>
#enf of sample.rb

$ ruby sample.rb
"http://localhost/a.jpg"
"link"