Assuming that you have a legitimate need to capture social security numbers (human resources app?), you may want to validate and format them consistently. The actual code for both languages combined is a little bit too long to post, so I'll just talk about the algorithm.
A social security number is a nine-digit number and can be matched with the following regular expression: ^\d{3}\-?\d{2}\-?\d{4}$
. If it can't pass this test, it's not a valid social security number. However, passing this simple test doesn't guarantee validity, so we need to keep checking.
- No digit group can consist of only zeros, and the first group cannot be 666. We check for these errors with the following regular expression:
((000|666)\-?\d{2}\-?\d{4}|\d{3}\-?00\-?\d{4}|\d{3}\-?\d{2}\-?0000
. - Numbers from 987-65-4320 to 987-65-4329 are reserved for use in advertisements, and other previously legitimate numbers have been invalidated because of use in advertisments. We check for these errors with the following regular expression:
987\-?65\-?432\d{1}|042\-?10\-?3580|062\-?36\-?0749|078\-?05\-?1120|095\-?07\-?3645|128\-?03\-?6045|135\-?01\-?6629|141\-?18\-?6941|165\-?(16|18|20|22|24)\-?7999|189\-?09\-?2294|212\-?09\-?(7694|9999|219\-?09\-?9999|306\-?30\-?2348|308\-?12\-?5070|468\-?28\-?8779|549\-?24\-?1889)
- Last but not least, the first three numbers are never higher than 772 (well, not yet; this could change in the future). For this I used a simple string conversion and numeric comparison.
The complete, commented source code is available on Snipplr:
Next week we'll head north of the border to my country and see what the Canadian equivalent of the Social Security Number is, and how we can validate them.
3 comments:
It seems the Drupal policy on outside code restricts to GPL only. Would you be willing to change the license over to GPL?
That's the biggest reason why I didn't license my code under GPL in the first place: I didn't want to restrict people from using it in non-GPL works.
I know that's not the answer you want to hear, but I do have a solution for you. The code is not very complicated, so you could probably write your own equivalent using my code only as reference.
What I recommend for attribution is just a link back to this blog post. I personally find it helpful when going through someone's code (or even my own several months later) to see where the heck something came from.
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