How to prevent users from entering contact information (emails/phone numbers) in text inputs?

Question

I am working on an app that will eventually allow users to connect with each other, but first a user will be able to post some public information and I want to block them from posting contact information (mainly email and phone numbers).

Is there an algorithm or approach for iOS or PHP that can detect such information? (Note - This is not a simple regular expression. I want to prevent common "tricky" ways of users displaying their contact info to the public).

Examples of what I want to block:

• Call me at 123-123-1234
• Call me at one-two-three onetwothree one two three four
• Email me [email protected]
• Message me john smith at g mail dot com

Obviously, there are unlimited derivations of the above examples and others, so I can't just create a "quick" expression matching algorithm for them all.

I know there probably isn't a 100% perfect approach for this, but was curious if there was something out there that would be better than making my own from scratch.

Answer 1

For email I always use this regex

 ("([a-zA-Z0-9._%+-]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)")

for other emails, instead of using regex use string searches

if line.tolower.contains("dot") and line.tolower.contains("com")
or if line.tolower.contains("@") and "com"
or if line.tolower.contains("@") and "net"
or if line.tolower.contains("mail") and "com"
or if line.tolower.contains("gmail") or "Yahoo" or "hotmail" or "bing"

As you can see, you are going to have to make quite a few rules

For Phone Numbers

("(?:\b\d{10,11}\b)")
("[0-9][0-9][0-9]-[0-9][0-9][0-9][0-9]")

Then like the emails, you will have to use .Contains

The only way to make sure you cover every number out there - you will need to add every area code in letter form in a series like:

"twosixfive"
"fourninesix"

as well as:

"two six five"
"four nine six"

as well as:

"two-six-five"
"four-nine-six"

here is a list of all the area codes: http://en.wikipedia.org/wiki/List_of_NANP_area_codes

There's not that many, you just have to be willing to take the time to do it.