I'll second Joost's approach, but make a few suggestions for readability / maintainability.

• Use qw so to de-clutter the list of strings.
• Use an explicit variable in the for; they are cheap and they make your intention clear.
• Use [ ] braces for the the regex separator so you won't have to backslash the slash. This de-emphasizes some of the executable line noise effect
• Use the regex x modifier to put some whitespace and comments in here.

foreach my field (qw(postby title teaser content)){
  $in{$field} =~ s[ (\r? \n){2,} ]          # two or more CR
                  [ \n </p> \n <p> \n]gx;   # Close one para, open ano
+ther
}
[download]

throop

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.