Validating BlackBerry PIN codes in Perl

is_valid_bb_pin.pl

#
# Validating a BlackBerry PIN in Perl.
#
# Andrey Butov ( andreybutov.com )
#

my $pin = <get PIN from submitted web page data>
return “Error” if !defined($pin);
$pin = &trimAndUpper($pin);

# Test for length validity.
return “Error” unless length($pin) == 8;

# Test for hex validity.
return “Error” unless ($pin =~ /^[[:xdigit:]]+$/);

# Good PIN at this point.

sub trimAndUpper {
  my ($str) = @_;
  $str =~ s/^\s+//; # left trim
  $str =~ s/\s+$//; # right trim
  $str =~ tr/a-z/A-Z/; # to upper
  return $str;
}