Google's libphonenumber is a universal library for parsing, validating, identifying and formatting phone numbers. It works quite well for numbers from just about anywhere. Here is a Java code sample (C++ and JavaScript also supported) from their web site:
String swissNumberStr = "044 668 18 00";
PhoneNumberUtil phoneUtil = PhoneNumberUtil.getInstance();
try {
PhoneNumber swissNumberProto = phoneUtil.parse(swissNumberStr, "CH");
} catch (NumberParseException e) {
System.err.println("NumberParseException was thrown: " + e.toString());
}
boolean isValid = phoneUtil.isValidNumber(swissNumberProto); // returns true
// Produces "+41 44 668 18 00"
System.out.println(phoneUtil.format(swissNumberProto, PhoneNumberFormat.INTERNATIONAL));
// Produces "044 668 18 00"
System.out.println(phoneUtil.format(swissNumberProto, PhoneNumberFormat.NATIONAL));
// Produces "+41446681800"
System.out.println(phoneUtil.format(swissNumberProto, PhoneNumberFormat.E164));
This is particularly useful for anybody working with international phone numbers. This is a common requirement in the world of VoIP where people mix-and-match phones and hosted PBXes in different countries and all their numbers have to be normalized.
The new libphonenumber package provides support for C++ and Java users. Upstream also supports JavaScript but that hasn't been packaged yet.
Lumicall, the secure SIP/ZRTP client for Android, has had libphonenumber from the beginning. It is essential when converting dialed numbers into E.164 format to make ENUM queries and it is also helpful to normalize all the numbers before passing them to VoIP gateways.
Debian includes the GNOME Evolution suite and it will use libphonenumber to improve handling of phone numbers in contact records if enabled at compile time. Fredrik has submitted a patch for that in Debian.
Many more applications can potentially benefit from this too. libphonenumber is released under an Apache license so it is compatible with the Mozilla license and suitable for use in Thunderbird plugins.
It is hard to keep up with the changes in dialing codes around the world. Phone companies and sometimes even whole countries come and go from time to time. Numbering plans change to add extra digits. New prefixes are created for new mobile networks. libphonenumber contains metadata for all the countries and telephone numbers that the authors are aware of but they also welcome feedback through their mailing list for anything that is not quite right.
Now that libphonenumber is available as a package, it may be helpful for somebody to try and find a way to split the metadata from the code so that metadata changes could be distributed through the stable updates catalog along with other volatile packages such as anti-virus patterns.