pan
Cares about PANs (Primary Account Number).
Examples
require 'pan'
pan = '1234567890123456'
Pan.mask(pan)
#=> '123456******3456'
pan
#=> '1234567890123456'
Pan.truncate(pan)
#=> '123456******3456'
pan
#=> '123456******3456'(Yes, that's the difference between masking and truncating a PAN in PCI DSS terminology.)
You may decide how much to mask (or truncate) and the character(s) that the digits are replaced with:
Pan.template = [0, 'x', 4]
Pan.mask('1234567890123456')
#=> 'xxxxxxxxxxxx3456'pan = '1234567890123456'
Pan.mask(pan, template: [4, 'X', 4])
#=> '1234XXXXXXXX3456'
Pan.truncate(pan, template: [6, '*', 4]); pan
#=> '123456******3456'