J2U

In order to use J2U, you will have to cut'n'paste the source code below into a file called "j2u.java" and compile it with a Java compiler like javac. An applet version is in the works.

J2U's default encoding is EUC-JP, the Unix standard for Japanese. Note that J2U handles almost any 8-bit encoding (like EUC and Shift-JIS), but cannot deal with purely 7-bit encodings like JIS since it can't tell where the "special" characters start.

/*
 * j2u.java by gn0sis
 * syntax: java j2u [input-encoding] <input >output
 * converts random local encoding (default EUC-JP) to
 * HTML Unicode character entities
 */
import java.io.*;

public class j2u {
  public static void main(String args[]) {    
    try {
      String encoding = "EUC-JP";
      if(args.length > 1) encoding = args[1];
      BufferedReader in = new BufferedReader
        (new InputStreamReader(System.in, encoding));
      String buf;
      while((buf = in.readLine()) != null) {
        for(int i = 0; i < buf.length(); i++) {
          char c = buf.charAt(i);
          if(Character.UnicodeBlock.of(c) !=
             Character.UnicodeBlock.BASIC_LATIN) {
            byte hi = (byte) (c >>> 8);
            byte lo = (byte) (c & 0xff);
            System.out.print("&#x" +
                     byteToHex(hi) + byteToHex(lo) +
                     ";");
          } else {
            System.out.print(c);
          }
        }
        System.out.println("");
      }
    } catch(IOException ioe) {
      ioe.printStackTrace();
    }
  }

  static public String byteToHex(byte b) {
    // Returns hex String representation of byte b
    char hexDigit[] = {
     '0', '1', '2', '3', '4', '5', '6', '7',
     '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'
    };
    char[] array = { hexDigit[(b >> 4) & 0x0f], hexDigit[b & 0x0f] };
    return new String(array);
   }
}