my $display_id = $q->param('display_id') // my_fatal_error_handler();
# Error if $display_id is undef
open my $fh, '<', $display_id or my_fatal_error_handler();
print $q->header;
print '';
# Page output here
# Do not include the tag once you
# have detected the command is finished, or redirect
# to another page/script
close $fh;
unlink $display_id;