Question

I can’t seem to get the proper RegEx for validating an IP address, including support for a wildcard char (*), which can occur only at the end. For example:

Valid

1.2.*
1.2.3.*
1.2.3.4

Not Valid

1
1.2
1.2*
1.2.3
1.2.3*
1.*.3.4

I’ve come close (and found a few similar questions/answers here), but can’t get all of the scenarios to pass/fail. Can anyone help me out? BTW – validating octets are 0-255 isn’t necessary, but would be cool.

Answer 1

something like this:

^((((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))|(((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}\*)|(((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){2}\*)|(((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){1}\*))$

second edition:

^((((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))|(((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){1,3}\*))$