BinaryDump.java


Below is the syntax highlighted version of BinaryDump.java from §5.5 Data Compression.


/******************************************************************************
 *  Compilation:  javac BinaryDump.java
 *  Execution:    java BinaryDump N < file
 *  Dependencies: BinaryStdIn.java
 *  Data file:    http://introcs.cs.princeton.edu/stdlib/abra.txt
 *  
 *  Reads in a binary file and writes out the bits, N per line.
 *
 *  % more abra.txt 
 *  ABRACADABRA!
 *
 *  % java BinaryDump 16 < abra.txt
 *  0100000101000010
 *  0101001001000001
 *  0100001101000001
 *  0100010001000001
 *  0100001001010010
 *  0100000100100001
 *  96 bits
 *
 ******************************************************************************/

/**
 *  The {@code BinaryDump} class provides a client for displaying the contents
 *  of a binary file in binary.
 *  <p>
 *  For more full-featured versions, see the Unix utilities
 *  {@code od} (octal dump) and {@code hexdump} (hexadecimal dump).
 *  <p>
 *  For additional documentation,
 *  see <a href="https://algs4.cs.princeton.edu/55compress">Section 5.5</a> of
 *  <i>Algorithms, 4th Edition</i> by Robert Sedgewick and Kevin Wayne.
 *  <p>
 *  See also {@link HexDump} and {@link PictureDump}.
 *
 *  @author Robert Sedgewick
 *  @author Kevin Wayne
 */
public class BinaryDump {

    // Do not instantiate.
    private BinaryDump() { }

    /**
     * Reads in a sequence of bytes from standard input and writes
     * them to standard output in binary, k bits per line,
     * where k is given as a command-line integer (defaults
     * to 16 if no integer is specified); also writes the number
     * of bits.
     *
     * @param args the command-line arguments
     */
    public static void main(String[] args) {
        int bitsPerLine = 16;
        if (args.length == 1) {
            bitsPerLine = Integer.parseInt(args[0]);
        }

        int count;
        for (count = 0; !BinaryStdIn.isEmpty(); count++) {
            if (bitsPerLine == 0) {
                BinaryStdIn.readBoolean();
                continue;
            }
            else if (count != 0 && count % bitsPerLine == 0) StdOut.println();
            if (BinaryStdIn.readBoolean()) StdOut.print(1);
            else                           StdOut.print(0);
        }
        if (bitsPerLine != 0) StdOut.println();
        StdOut.println(count + " bits");
    }
}


Copyright © 2000–2017, Robert Sedgewick and Kevin Wayne.
Last updated: Fri Oct 20 12:50:46 EDT 2017.