Someone

#!/usr/bin/perl -w -s

open FILE, "file.txt" or die $!;
my $line_num = 0;
my $FLAG = 0;
my $compile = 0;
my $error = 0;

while (my $line = <FILE>)
{
    $line_num++;
    chomp($line);

    my $index = substr($line, 0, 5);

    if ($FLAG == 1) {
        $line=~/CUST#:.+?(\w.+)PMT\$:\s+(.+)\s/;
         
        if (!defined $1 || $1 eq "000000") {
            $error = 1;
            next; #didn't provide cust #
        }

        if (!defined $2) {
            $error = 1;
            next; #no payment?
        }
        
        $custnum = $1;
        $payment = $2;
        
        $FLAG = 0;
        $compile = 1;
    }

    if ($index eq "REMIT") {
        $line=~/TTER:\s(.+?)\s+CK#:.+?([1-9].+)\sCK/;
        
        if (!defined $1) {
            $error = 1;
            next; #jump to next record. Can't compare to cust #
        }

        if (!defined $2) {
            $2 = "1234"; #check # not found. Give one instead
        }

        $name = $1;
        $cknum = $2;

        $FLAG = 1;
    }

    if ($compile == 1) {
        push(@names, $name);
        push(@cknums, $cknum);   
        push(@custnums, $custnum);
        push(@payments, $payment);

        $compile = 0;
    }
}

continue {
    if ($error == 1) {
        $line=~s/^\s+|\s+$//g; #Sanatize line
        push(@errors, "Error: at line ".$line_num.": ".$line."\n");
        $error = 0;
    }
}

open RESULT, ">output.txt";

my $total = 0;
for ($i=0;$i<scalar(@payments);$i++) {
    $total = $payments[$i] + $total;
}
print RESULT $total."\n";

for ($i=0;$i<scalar(@names);$i++) {
    print RESULT "$names[$i],$cknums[$i],$custnums[$i],$payments[$i]\n";
}

for ($i=0;$i<scalar(@errors);$i++) {
    print "$errors[$i]\n";
}
       
close FILE;
close RESULT;