That will break on files with spaces, newlines or other funny characters in their name. Try
perl -e 'for(@ARGV) { my $o = $_; s/DOTX/DOT_TEST/ && warn "*** $o, $_" }' *
It also saves a process.
Makeshifts last the longest.
Comment on Re: [perlrun; perlre] $_ seems aliased instead of copied in assignment... why?