Somthing like this is a bit more robust and writes a backup just in case it destroys stuff ;-) The [^<] class works well for REs in HTML where you want to match potential multilines. There are of course edge cases where < could be valid content between tags. You deal with them with a forward lookahead ([^<]+|<(?!\s*/))* and alternation.

This sort of thing is a quick and dirty solution, the parsing modules or templating are better.

perl -pi.bak -e 's#<\s*title\s*>([^<]+|<(?!\s*/))*<\s*/\s*title\s*>#<t
+itile>New Title</title>#i' <files>

# this will correctly parse horrid stuff like
<TiTle >
One is < two
more
stuff
</ title>
<foo>bar</foo>
[download]

cheers

tachyon

s&&rsenoyhcatreve&&&s&n.+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print