$ perl -e 'print "broken\n" if "foo"  =~ /[.]/'
   $ perl -e 'print "ok\n"     if "foo." =~ /[.]/'
   ok
[download]

The period is not magical inside a character class.

-sam

Removed: I learn something new every day on this site!

Unfortunately, nobody else gets to, because you removed the node instead of updating it. Please consider that next time, so others can get the full context of the thread and benefit in the mutual learning opportunity.