content: /*************************************************************************
   *  Compilation:  javac HexDump.java
   *  Execution:    java HexDump < file
   *  Dependencies: BinaryStdIn.java
   *  Data file:    http://introcs.cs.princeton.edu/stdlib/abra.txt
   *  
   *  Reads in a binary file and writes out the bytes in hex, 16 per line.
   *
   *  % more abra.txt
   *  ABRACADABRA!
   *
   *  % java HexDump 16 < abra.txt
   *  41 42 52 41 43 41 44 41 42 52 41 21
   *  96 bits
   *
   *  % hexdump < abra.txt
   *
   *  % od -t x1 < abra.txt 
   *  0000000 41 42 52 41 43 41 44 41 42 52 41 21
   *  0000014
   *
   *************************************************************************/
  
  public class HexDump {
  
      public static void main(String[] args) {
          int BYTES_PER_LINE = 16;
          if (args.length == 1) {
              BYTES_PER_LINE = Integer.parseInt(args[0]);
          }
  
          int i;
          for (i = 0; !BinaryStdIn.isEmpty(); i++) {
              if (BYTES_PER_LINE == 0) { BinaryStdIn.readChar(); continue; }
              if (i == 0) StdOut.printf("");
              else if (i % BYTES_PER_LINE == 0) StdOut.printf("\n", i);
              else StdOut.print(" ");
              char c = BinaryStdIn.readChar();
              StdOut.printf("%02x", c & 0xff);
          }
          if (BYTES_PER_LINE != 0) StdOut.println();
          StdOut.println((i*8) + " bits");
      }
  }
  