validdate.cpp

这是一个MIS中使用过正则式

//
// ValidDate.cpp
//
// Input date, use regular expression to test the date is valid or invalid
//
// L.F.
// 2006-04.03
//

#include <string>
#include <iostream>
#include <boost/regex.hpp>

#if defined(BOOST_MSVC) || (defined(__BORLANDC__) && (__BORLANDC__ == 0x550))
// problem with std::getline under MSVC6sp3
std::istream& getline( std::istream& is, std::string& s )
{
	s.erase();
	char c = is.get();
	while ( c != '\n' )
	{
		s.append( 1, c );
		c = is.get();
	}
	return is;
}
#endif

std::string validDate = std::string(
				"^(?:"
				"([0-9]{4}-(?:(?:0?[1,3-9]|1[0-2])-(?:29|30)|((?:0?[13578]|1[02])-31)))"
				"|"
				"([0-9]{4}-(?:0?[1-9]|1[0-2])-(?:0?[1-9]|1\\d|2[0-8]))"
				"|"
				"((?:(\\d\\d(?:0[48]|[2468][048]|[13579][26]))|(?:0[48]00|[2468][048]00|[13579][26]00))-0?2-29)"
				")$"
);
boost::regex e( validDate, boost::regbase::normal );


int main( int argc )
{
	std::string lineText;

	do {
		if ( argc == 1 )
		{
			std::cout << "PLEASE INPUT THE DATE <\"QUIT\" EXIT THE PROGRAM>" << std::endl;

			getline( std::cin, lineText );

			if ( lineText == "QUIT" )
				break;
		}

		std::cout << "\t=========================================================" << std::endl;
		std::cout << std::endl;	
		if ( boost::regex_match( lineText, e ) )
				std::cout << "\tVALID DATE" << std::endl;
		else
				std::cout << "\tINVALID DATE" << std::endl;

		std::cout << "\tTHE DATE YOU INPUT IS : " << lineText << std::endl;
		std::cout << "\tExpression is :" << validDate << std::endl;
		std::cout << std::endl;
		std::cout << "\t=========================================================" << std::endl;
	} while ( argc == 1 );
	
	return 0;
}