[Boost-users] [Help on implementation of boost regex]

1 Aug 2004

      Hello,

I try to use boost regex . I don't have a lot of experience of using
boost regex . Boost regex examples aren't so explicit for me. So I need
some help to parse this example file.

Point(1) = {0,0,0,0.1};
Point(2) = {1,0,0,0.1};
Point(3) = {0,1,0,0.1};
Point(4) = {1,1,0,0.1};
Line(1) = {1,2};
Line(2) = {2,4};
Line(3) = {4,3};
Line(4) = {3,1};
Line Loop(5) = {2,3,4,1};
Plane Surface(6) = {5};

I can't read each informations to use it after.
I can't match for use IdentificationNumber of Point(IdentificationNumber).
Actually my code look so :

   /*
g++ -Wall -O2 -o ifstream ifstream.cc
*/

#include <iostream>
#include <fstream>
#include <string>

/* boost regex header */
#include <boost/regex.hpp>

using namespace std;
using namespace boost;

int
main (int argc, char argv[])
{
	char buffer[256];
	string filename;
	string inputstring;

	cout << "Input filename ";
	cin >> filename;
	ifstream readfile (filename.c_str (), ios::in);

	if (!readfile.is_open ())
	{
		cout << "Error opening file" << endl;
		return 0;
	}

	regex exPoint ("Point");
	regex exLine ("Line");
	regex IdentificationNumber ("[:digit:]");

	while (!readfile.eof ())
	{
		readfile.getline (buffer, 200);
		inputstring = buffer;

		if (regex_search (inputstring, exPoint))
		{
			cout << "Point" << endl;
			smatch result;
			if (regex_search
			    (inputstring, result, IdentificationNumber))
			{
				cout << "Identification Number " << result << endl;
				}
			else
				cout << "Error regex_match" << endl;
		}
		if (regex_search (inputstring, exLine))
		{
			cout << "Line" << endl;
		}
		cout << buffer << endl;
	}

	readfile.close ();

	return (0);
}

Thank you for help. Best regards

hackervalley
http://hackervalley.free.fr