Regular expression: how to match "[somestuff]"?

Question

I have a problem with the following code.
I meant to catch "[fm1,-]". But I got "[fm1,-] funder [fm2,-] of our country. [sn8,s-]" instead.
import java.util.*;
import java.util.regex.*;
public class regPractice {
public static void main(String[] args) {
String s="<TITLE Getting to Know> I hope suitabe [fm1,-] funder [fm2,-] of our country. [sn8,s-]";
Pattern p=Pattern.compile("\\[(.*)\\]");
Matcher m=p.matcher(s);
if (m.find() ){
System.out.println(m.group(0) ) ;
}else{
System.out.println("Nothing");
}

Answer 1

Regular expressions are greedy - that is (.*) will grab as much as it
possibly can before a ]. Hence you see what you see.
What you want is a reluctant quantifier, in this case (.*?)
These grab as little as they possibly can. The parentheses are also
not needed in your example, but you may want group(1) for some
other reason.
So we end up with:import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class regPractice {
    public static void main(String[] args) {
        String s = "<TITLE Getting to Know> I hope suitabe [fm1,-] funder [fm2,-] of our country. [sn8,s-]";
        Pattern p = Pattern.compile("\\[(.*?)\\]");
        Matcher m = p.matcher(s);
        if (m.find()) {
            System.out.println(m.group(0));
        } else {
            System.out.println("Nothing");
}which gives the desired output.
The different types of quantifier are described here:
http://java.sun.com/docs/books/tutorial/extra/regex/quant.html