package file.extendsion;

import java.io.ByteArrayOutputStream;

import java.io.File;

import java.io.FileInputStream;

public class LnkParser {

    // http://www.oschina.net/code/snippet_12_274

    public static void main(String[] args) throws Exception {

        new LnkParser(new File("e:/eclipse.lnk"));

    }

    public LnkParser(File f) throws Exception {

        parse(f);

    }

    private boolean is_dir;

    public boolean isDirectory() {

        return is_dir;

    }

    private String real_file;

    public String getRealFilename() {

        return real_file;

    }

    public void parse(File f) throws Exception {

        // read the entire file into a byte buffer

        FileInputStream fin = new FileInputStream(f);

        ByteArrayOutputStream bout = new ByteArrayOutputStream();

        byte[] buff = new byte[256];

        while (true) {

            int n = fin.read(buff);

            if (n == -1) {

                break;

            }

            bout.write(buff, 0, n);

        }

        fin.close();

        byte[] link = bout.toByteArray();

        // get the flags byte

        byte flags = link[0x14];

        // get the file attributes byte

        final int file_atts_offset = 0x18;

        byte fileatts = link[file_atts_offset];

        byte is_dir_mask = (byte) 0x10;

        if ((fileatts & is_dir_mask) > 0) {

            is_dir = true;

        } else {

            is_dir = false;

        }

        // if the shell settings are present, skip them

        final int shell_offset = 0x4c;

        int shell_len = 0;

        if ((flags & 0x1) > 0) {

            // the plus 2 accounts for the length marker itself

            shell_len = bytes2short(link, shell_offset) + 2;

        }

        // get to the file settings

        int file_start = 0x4c + shell_len;

        // get the local volume and local system values

        int local_sys_off = link[file_start + 0x10] + file_start;

        real_file = getNullDelimitedString(link, local_sys_off);

        p("real filename = " + real_file);

    }

    static String getNullDelimitedString(byte[] bytes, int off) {

        int len = 0;

        // count bytes until the null character (0)

        while (true) {

            if (bytes[off + len] == 0) {

                break;

            }

            len++;

        }

        return new String(bytes, off, len);

    }

    // convert two bytes into a short // note, this is little endian because

    // it's for an // Intel only OS.

    static int bytes2short(byte[] bytes, int off) {

        return bytes[off] | (bytes[off + 1] << 8);

    }

    /*

     * static int norm(byte b) { if(b < 0) { b+=128; } return b; } static int

     * bytes2int(byte[] arr, int off) { int b1 = norm(arr[off]); int b2 =

     * norm(arr[off+1]); int b3 = norm(arr[off+2]); int b4 = norm(arr[off+3]);

     * int val = ( (b1 << 0) | (b2 << 8) | (b3 << 16) | (b4 << 24) );

     * //p("bytes2int: " + b1 + " " + b2 + " " + b3 + " " + b4); return val; }

     *

     *

     * static NumberFormat num_format = new DecimalFormat(" 000;-000");

     *

     * public static String padd(String str, int len) { while(str.length() <

     * len) { str = " " + str; } return str; }

     *

     * public static void pw(byte[] arr, int off) { StringBuffer top = new

     * StringBuffer(); StringBuffer mid = new StringBuffer(); StringBuffer bot =

     * new StringBuffer(); top.append("--"); mid.append("  "); bot.append("  ");

     *

     * for(int i=0; i<16; i++) { int val = arr[off+i]; String str =

     * Integer.toHexString(off+i); top.append(padd(str,5));

     * mid.append(padd(""+val,5)); if(val < 0) { val += 128; } if(val >= ' ' &&

     * val <= '~') { str = "" + (char)val; } else { str =

     * Integer.toHexString(val); } str = padd(str,5); bot.append(str);

     * if(i%4==3) { top.append("    "); mid.append("    "); bot.append("    ");

     * } } p(top.toString()); p(mid.toString()); p(bot.toString()); } public

     * static void pbits(byte bt) { p("byte = " + bt + " " +

     * Integer.toHexString(bt) + " " + Integer.toBinaryString(bt)); }

     */

    public static void p(String str) {

        System.out.println(str);

    }

}