open DR, ">ddailyreport.prn" or die "Can't open file";

# Naming a format the same as a file handle automatically associates the format
# to the data handle.
format DR =
  @<<<<<<<<<<<<<<<<<<<<<<<  @<<<<<<<<<<<<<<<  @#####  @###############  Rs@#####.##  ~
  $consname, $subdvn, $chequeno, $receiptno, $amount
.

# Similarly, adding _TOP to the format name gives you automatic top-of-form
# handling.
format DR_TOP =
  @||||||||||||||||||||||||||||||||||||  Pg @<
  "Daily Deposit Works Report",        $%

  Consumer name         Subdivision      Cheque no.      Receipt no.       Amount
  --------------        --------------   -------------   --------------    -------
.

format TOTAL =
  -------------------------------------------------------------------------------------------
                                                                        Rs@#####.##
                                                                        $total
.

sub dotize {
    my($width, $string) = @_;

    if (length($string) > $width) {
        return(substr($string, 0, $width - 3) . "...");
    }
    else {
        return($string);
    }
}

# Two things:
# (1) This is not needed, per notes above...
# (2) The $~ variable associates a format FOR THE DEFAULT OUTPUT
#     STREAM, so you just changed it for stdout.  You would really
#     use:
#          my $ofh = select(DR); # make DR the default output
#          $~ = "DR";            # set format for detail lines
#          $^ = "DR_TOP";        # set format for top-of-page
#          select($ofh);         # Restore default output stream
#     
#$~ = "TOP";
#write(DR);


open(FILE, "<ddailyreport.txt");
@lines = <FILE>;
close(FILE);

$total = 0;
foreach (@lines) {
    chop();
    ($consname, $subdvn, $chequeno, $receiptno, $amount) = (split(/!/));
    $consname  = "" if !defined($consname);
    $subdvn = "" if !defined($subdvn);
    $chequeno  = 0 if !defined($chequeno);
    $receiptno  = 0 if !defined($receiptno);
    $amount= 0 if !defined($amount);
    # You need only do the association of the format once.  You only need
    # to do it again if you're going to change it...
    #$~ = "DATA";
    write(DR);
    $total += $amount;
}

# Now we change the output format for your summary
my $ofh = select(DR);
$~ = "TOTAL";
select($ofh);

write(DR);

close(DR);