Elog, Java interpreter

import java.io.FileReader;
import java.util.LinkedList;
import java.util.Scanner;

public class ElogPT {
    public static void main(String[] args) {
        if(args.length == 0) {
            Scanner sc = new Scanner(System.in);
            run(sc.next(), sc.next());
        } else if(args.length == 1) run(readFile(args[0]), "");
        else if(args.length > 1) {
            String f = readFile(args[0]);
            for(int i=1;i<args.length;run(f, args[i++]));
        }
    }

    public static void run(String s, String in) {
        int cur = 0, sts = 0;
        LinkedList<Boolean> st = new LinkedList<Boolean>();
        boolean[] ins = new boolean[in.length()];
        int[] vars = new int[256];
        for(int i=0;i<256;vars[i++] = -1);
        for(int i=0;i<in.length();ins[i] = (Character.getNumericValue(in.charAt(i++)))==0?false:true);
        for(char c: s.toCharArray()) {
            if(sts == 0) {
                if(c == ';') sts = 2;
                else if(c == ':') sts = 1;
                else if(c == '.') st.push(st.peek());

                else if(c == '\'') {
                    boolean b = st.pop();
                    st.push(b?false:true);
                } else if(c == '&') {
                    boolean b1 = st.pop(), b2 = st.pop();
                    st.push(b1 && b2);
                } else if(c == '|'){
                    boolean b1 = st.pop(), b2 = st.pop();
                    st.push(b1 || b2);
                } else if(c == '^') {
                    boolean b1 = st.pop(), b2 = st.pop();
                    st.push(b1 ^ b2);
                }

                else if(c == '0') st.push(false);
                else if(c == '1') st.push(true);
                else if(c > 20){
                    if(vars[c] == -1) vars[c] = (ins[cur++]?1:0);
                    if(vars[c] > -1) st.push(vars[c]==1);
                }
            } else if(sts == 1 && c > 20) {
                vars[c] = (st.pop()?1:0);
                sts = 0;
            } else if(c > 20) if(c == '0' || c == '1') System.out.print(c); else System.out.print(vars[c]);
        }
        System.out.println();
    }

    public static String readFile(String filename) {
        String result = "";
        try {
            FileReader r = new FileReader(filename);
            int c;
            while((c = r.read()) != -1)
                result += (char)c;
        } catch(Exception e) {
            System.out.println(e.getMessage());
        }
        return result;
    }
}