import java.io.*;
import java.util.*;
import java.util.regex.*;

public class RegEx1 {
    public static void main(String[] args) throws Exception {
        // We have 3 possible values for our pattern.
        // This one matches a sequence of the characters 's', 't', 'e', or 'm'.
        String pat = "([stem]+)";

        // The carat at the front of the square brackets negates the group.
        // Thus, this pattern matches any sequence of characters that is not 's', 't', 'e', or 'm'.
        //String pat = "([^stem]+)";

        // The use of pipe symbols "|" provides a choice. The regular expression
        // can match "pat" or "match" or "File".
        //String pat = "(pat|match|File)";
        Scanner s = new Scanner(new File(args[0]));
        while(s.hasNextLine()) {
            if(s.findInLine(pat) != null) {
                MatchResult m = s.match();
                System.out.println("Match: "+m.group(1));
            }
            s.nextLine();
        }
    }
}