c# - Parsing multiple groups -

i have html file(i can't use html agilitypack) want extract id of div(if has one)

<div id="div1">street ___________________ </div> <div id="div2">cap |__|__|__|__|__| number ______ </div> <div id="div3">city _____________________ state |__|__|</div> <div id="div4">city2 ____________________ state2 _____</div> 

i have pattern extracting underscores __ : [\ _]{3,}

now if have div in front of underscores want extract it, if not i'll underscores.

i have build far pattern (<div id(.+?)>(\w)([\ _]{3,}/*))([\ _]{3,})

the first part build out of 3 groups 1 - div tag, 2 - label, 3 - underscores

1 - <div id(.+?)>, 2 - (\w) , 3 - [\ _]{3,}/*

the div id div2 not take id because contains non-alfanumeric chars.

q: wrong pattern ?

desired matchs 4 divs:

<div id="div1">street ___________________ ______  <div id="div3">city _____________________ <div id="div4">city2 ____________________ _____ 

• \w single character, want 1 or more - \w+.

• /* - 0 or more /'s? don't see fits in.

• one or more not >'s (i.e. [^>]+) better idea .+?. .+? try stop @ first >, continue until finds string matches, i.e.:

  <div id=1>this not valid</div><div id=2>this valid___</div> 

  will match whole string, instead of <div id=2>.

• as far can tell question, before underscores should optional.

pattern:

(?:(<div id[^>]+>)(\w+))?([\ _]{3,}) 

c# test.