re = /<([^>]*)>[^><]*<\/\s*\1\s*>|<(\w+)\s+[^>]*>[^><]*<\/\s*\2\s*>/m
str = '<div id="MyDiv">div,
<strong>
<span>span2, </span> <-- This is to delete
<em> Some text for em
<div> Some text for div </div> <-- This is to delete
<p><b>b, <span id="MySpan"> Some text for span ...
<b style="z-index:1;"> text ... </ b >'
subst = ''
result = str.gsub(re, subst)
# Print the result of the substitution
puts result
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html