This is as more about the learning process than the actual task... but I can't see what's wrong with my regex, and I'd appreciate any pointers. I want to find cases where a header is not followed by a line break, e.g. "== External links ==;http://www.americanbamboo.org/GeneralInfo.html I tried various regex strings, including "([\r\n]==[^\n=]*==)([^=\r ])" (allowing for the fact that excess spaces on the end aren't important) to be replaced by "\\1\n\\2" But I get many false matches. See http://www.pastie.org/913753 for details of the good and the false matches. In #regex on freenode I was told to try: "s/((={2,}).*?\2)(?!\n)([^=]?)/\1\n\2/g" but it gives the error: "bash: !\n: event not found". I'm told that it works - http://pastie.org/913765 - but in my terminal I can't get past the bash error. Thanks! -- Chris Watkins Appropedia.org - Sharing knowledge to build rich, sustainable lives. blogs.appropedia.org community.livejournal.com/appropedia identi.ca/appropedia twitter.com/appropedia