If $LANG contains "utf8", then [^\w] doesn't work right:

      setenv LANG en_US
      echo -n "foo.bar" | \
      perl -e '$_ = <>; print join (" | ", split (/([^\w]+)/)) . "\n";'

            ===> "foo | . | bar" (right)


      setenv LANG en_US.utf8
      echo -n "foo.bar" | \
      perl -e '$_ = <>; print join (" | ", split (/([^\w]+)/)) . "\n";'

            ===> "foo.bar" (wrong!)


It works fine in both cases if you do $_ = "foo.bar" instead of reading
the text from stdin.

    This is perl, v5.8.0 built for i386-linux-thread-multi
    (with 1 registered patch, see perl -V for more detail)

    perl-5.8.0-88
    Red Hat Linux release 9 (Shrike)
    Linux 2.4.20-8smp #1 SMP Thu Mar 13 16:43:01 EST 2003 i686 athlon i386

Maybe this is a dup of 102106, I can't tell.