Module Version: 0.01   Source   Latest Release: Business-PT-BI-0.02

Version 0.01

# SYNOPSIS

```    use Business::PT::BI;

if ( valid_bi(\$bi, \$control_number) ) {
# ...
}```

# FUNCTIONS

## valid_bi

Validates Portuguese BI's.

A Portuguese BI number is comprised by eight digits. Between that number and the "issue" box, the card also has a small box with a single digit. That's the control digit. In order to validate a Portuguese BI, you have to provide `valid_bi` with the BI number and the control digit.

`  valid_bi( \$bi, \$control_number );`

Validation is done as follows:

``` 1) BI is matched with /^\d{8}\$/ (eigth consecutive digits with
nothing more)
2) First digit is multiplied by 9, second by 8, third by 7, fourth by
6, fifth by 5, sixth by 4, seventh by 3, eighth by 2
3) All the results of the multiplication are summed
4) Modulo of the sum by 11 is found
5) Complement of the sum by 11 is found
6) Control digit is compared to said complement```

Example for BI 12345678, with control digit 9:

``` 1) BI is matched with /^\d{8}/, test passes
2) Multiplication: 1*9, 2*8, 3*7, 4*6, 5*5, 6*4, 7*3, 8*2
3) Sum: 156
4) 156 % 11 = 2
5) 11 - 2 = 9
6) 9 == 9, test passes```

When the complement (the result of step 5) is greater than 9, the number is assumed to be 0.

# AUTHOR

Jose Castro, `<cog at cpan.org>`

# BUGS

Please report any bugs or feature requests to `bug-business-pt-bi at rt.cpan.org`, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Business-PT-BI. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

# SUPPORT

You can find documentation for this module with the perldoc command.

`    perldoc Business::PT::BI`

You can also look for information at: