import java.io.*;
import java.util.*;
import java.net.*;

class HrefReader {
    public HrefReader(String url) throws IOException {
	tr = new TagReader(url);
    }
    
    // return index of HREF href HrEf and so on in s
	private int hrefIndex(String s) {
	    return s.toUpperCase().indexOf("HREF");
	}
    
    // return the largest prefix of s that does not contain x with spaces trimmed
	private String trimFrom(String s, String x) {
	    int k = s.indexOf(x);
	    if (k!=-1)
		return s.substring(0,k).trim();
	    else
		return s.trim();
	}
    
    // return the largest suffix of s that does not contain x with spaces trimmed
	private String trimUpThrough(String s, String x) {
	    int k = s.indexOf(x);
	    if (k!=-1)
		return s.substring(k+x.length()).trim();
	    else
		return s.trim();
	}
    
    public String readLine() throws IOException {
	String tag;
	tag = tr.readLine();
	while (tag!=null && hrefIndex(tag)==-1)
	    tag = tr.readLine();
	if (tag==null)
	    return null;
	int k = hrefIndex(tag);
	tag = tag.substring(k+1).trim();
	tag = trimUpThrough(tag,"=");
	tag = trimFrom(tag," ");
	if (tag.indexOf("\"")!=-1) {
	    tag = trimUpThrough(tag,"\"");
	    tag = trimFrom(tag,"\"");
	}
	if (tag.indexOf("'")!=-1) { 
	    tag = trimUpThrough(tag,"'");
	    tag = trimFrom(tag,"'");
	}
	tag = trimFrom(tag,"#");
	return trimFrom(tag,"?");
    }
    
    private TagReader tr; // The TagReader to read tags from
}