C++11 Standard STL Regular expression verification e-mail address

Transferred from: http://www.cnblogs.com/yejianfei/archive/2012/10/07/2713715.html

The most common verification we encounter is email address verification. Common on the site. Various Web page scripts are also commonly used "regular Expressions" (Regular expression) to verify the e-mail address we enter and determine whether it is legal. Some can also break down the user name and domain name. Now implementation of the e-mail address validator in the C + + language, with the new C + + 11 standard added STL regular expression.

The source code is as follows, and the code has been validated on Visual Studio 2010. g++ 4.6 does not support C + + 11 STL Regular Expressions,g++ 4.6 can be compiled through, but run-time errors, throw regex_error exceptions. Therefore, if you want to use regular expressions on g++ 4.6, use the GNU Regular Expression library or the boost regular expression library.

1 /*2 * Regex.cpp-Verify e-mail address with regular expression3  *4 * C++11 Standard STL Regular Expression5  *6  *7 * Copyright Ye Jianfei8  *9 * Compile command:Ten * CL Regex.cpp/ehsc/link/out:regex.exe One  * A  */ -  -#include <iostream> the#include <cstdlib> -#include <string> -#include <regex>//Regular expression Regular Expressions -  + using namespacestd; -  + intMain () A { at     stringemail_address; -     stringuser_name, domain_name; -  -Regex pattern ("([0-9a-za-z\\-_\\.] +) @ ([0-9a-z]+\\. [A-z] {2,3} (\\. [A-z] {2})?)"); -     //regular expressions, matching rules: -     //group 1th (i.e. user name), matching rules: 0 to 9, A to Z, A to Z, underscore, dot, hyphen in     //any character, repeat over or above -     //Middle, an "@" symbol to     //The second group (that is, the domain name), matching rules: 0 to 9 or a to Z of any character repeats or more, +     //then a point, and then any character in A to Z repeats 2 to 3 times (such as COM or CN, etc.), -     //a group within the second group, a point, followed by any character in A to Z 2 times (e.g. CN or FR, etc.) the     //a whole group of internal repeats 0 or one time *  $ Panax Notoginseng     //Enter end of file (Windows uses Ctrl+z,unix with Ctrl+d) to close the loop -      while(Cin >>email_address) the     { +         if(Regex_match (email_address, pattern)) A         { thecout <<"The email address you entered is legal"<<Endl; +  -             //intercept the first group $user_name = Regex_replace (email_address, pattern,string(" $") ); $  -             //Intercept the second group -domain_name = Regex_replace (email_address, pattern,string(" $") ); the  -cout <<"User name:"<< user_name <<Endl;Wuyicout <<"Domain Name:"<< domain_name <<Endl; thecout <<Endl; -         } Wu         Else -         { Aboutcout <<"The email address you entered is not valid"<< Endl <<Endl; $         } -     } -     returnexit_success; -}