CGI Script sub

citabriabob has asked for the wisdom of the Perl Monks concerning the following question:

Hello, newbie here: Trying to add CC validation to script, but getting 500-errors. Have already checked and syntax is OK. Help?

sub sanity_checks {
  local(%data) = @_;
  local($any);

  if  (!($data{'26Email'} =~ /.+@.+\..+/)) {
    &print_error("The email address entered does not appear to be a va
+lid address.  Please enter an address in the form \"who\@where.com\".
+");
    return 0;
  } elsif ((!($data{'01Member'} =~ /^[0-9]{1,4}$/)) && ($data{'01Membe
+r'})) {
    &print_error("The member ID number is entered incorrectly.");
    return 0;

# check CC
  } elsif (processCard($data{'51CardNum'}) = 2) {
       &print_error("Credit Card Number Invalid please try again.");
    return 0;
  } elsif ($data{$_}){
      ++$any;
   }
  return 1;
}

# test CC number 11/7/2015
sub processCard {
    my ($cardNum) = @_;
#       &print_error("Test should be cc no. @_");
    return 2 if $cardNum !~ /^[0-9]+$/;
#    return 2 if length $cardNum != 16;
    return 2 if !numberOK($cardNum);
}

sub numberOK {
    my @cardNum = split //, shift;

    for my $i (map {$_ * 2} 0 .. $#cardNum / 2) {
        $cardNum[$i] *= 2;
        $cardNum[$i] -= 9 if $cardNum[$i] >= 10;
    }

    my $total = 0;
    $total += $_ for (@cardNum);
    return $total % 10 == 0;
}
# end processCard sub
[download]

Comment on CGI Script sub Download Code

Replies are listed 'Best First'.
Re: CGI Script sub by davido (Cardinal) on Nov 08, 2015 at 22:41 UTC
One reason this code can't work is line 13: `} elsif (processCard($data{'51CardNum'}) = 2) {` [download] ...because that attempts to assign `2` to an lvalue sub named `processCard`, but that subroutine is not defined as an lvalue sub. I'm sure you intended to use the relational `==` operator: `} elsif (processCard($data{'51CardNum'}) == 2) {` [download] Also, on line 5: `if (!($data{'26Email'} =~ /.+@.+\..+/)) {` [download] It is by sheer luck that Perl is treating `@.` as the literal character `@`, and the metacharacter `.`. If what came after `@` were, instead, valid "identifier" characters, it would trigger variable interpolation. To be safe, precede the `@` inside of regular expressions (update: with a `\` escape) unless you intend for it to be treated as an array sigil. Dave	[reply] [d/l] [select]
Re^2: CGI Script sub by citabriabob (Novice) on Nov 08, 2015 at 22:52 UTC
Changing operator to == worked! Thank you all so much. Is there anyone out there that could review these scripts and offer suggestions? Paid, of course.	[reply]
Re^3: CGI Script sub by davido (Cardinal) on Nov 08, 2015 at 22:54 UTC
Check out http://jobs.perl.org, or one of the many freelance sites if you're looking to pay someone to do a code review. Here you get small amounts of professional quality help in return for asking interesting questions. ;) Dave	[reply]
Re^2: CGI Script sub by citabriabob (Novice) on Nov 08, 2015 at 23:16 UTC
Missed your note on line 5; do you mean a backslash before the @ character? Sorry to be so obtuse, but these string manipulations are difficult for me to see.	[reply]
Re^3: CGI Script sub by AnomalousMonk (Archbishop) on Nov 08, 2015 at 23:39 UTC
... a backslash before the [literal] @ character? Taking the liberty of replying for fellow monk davido: Yes. Give a man a fish: `<%-{-{-{-<`	[reply] [d/l]
Re: CGI Script sub by 1nickt (Canon) on Nov 08, 2015 at 22:40 UTC
Try putting `use CGI::Carp qw/ fatalsToBrowser /;` [download] at the top of your script. This will make the cause of the error appear in the browser. Right now it is in the web server error log. See CGI::Carp P.S. Also see Regexp::Common ... some of what you are doing has been done before ;-) The way forward always starts with a minimal test.	[reply] [d/l]