foreach my $file (@entries) {
        next if ($file =~ /^\.+$/);
        if ( -d $dir . '/' . $file) {
            runDir($prefix . $file . '_', $dir . '/' . $file);
             print "***up   runDir($prefix . $file . '_', $dir . '/' . $file)\n"; 

        } elsif ( ( -f $dir . '/' . $file ) && ( $file =~ /\.config$/ ) && ($file !~ /^$prefix/)) {
            my $suffix = $file;
            $suffix =~ s/^(\S+)-.+\.config$/$1.config/;
     
      print "****rename $dir . '/' . $file, $dir . '/' . $prefix . $suffix"."\n"; 
            rename $dir . '/' . $file, $dir . '/' . $prefix . $suffix ;
        }
    }

##</code><code>##

DCMS_DEMO_new_block2_checklist_tmp_rev2.html

##</code><code>##


prefix output:

***up   runDir(DCMS_DEMO_de_top_Block_DV_ . rev2 . '_', /home/sa/dcms_html_output/DCMS_DEMO/de_top/Block_DV . '/' . rev2)

suffix output:

Block_DV.config

rename output:

****rename 

/home/sa/dcms_html_output/DCMS_DEMO/de_top/Block_DV . '/' . Block_DV.config, /home/sa/dcms_html_output/DCMS_DEMO/de_top/Block_DV . '/' . DCMS_DEMO_de_top_Block_DV_ . Block_DV.config