Check which ports are open to the outside world. Helps make sure that your firewall rules are working as intended.
One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.
I would probably look in a slightly different way....
Searh for the ( and ) first (least likely to occur), then the block of 4 numerics, then walk backwards to check the area code and exchange prefix digits
Of course you also should consider the fact that some people don't put the punctuation where it should be (capitalisation, hyphens and spaces etc) so perhaps it is worth pre-processing and index that file against the source file to remove all ambiguities, only then scan for the formatted number strings, and only then refer back to the original file to extract the entry as actually keyed in... (if that's really necessary)