/****************************************************************************** * Compilation: javac HexDump.java * Execution: java HexDump < file * Dependencies: BinaryStdIn.java StdOut.java * Data file: https://algs4.cs.princeton.edu/55compression/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 * * * Remark * -------------------------- * - Similar to the Unix utilities od (octal dump) or hexdump (hexadecimal dump). * * % od -t x1 < abra.txt * 0000000 41 42 52 41 43 41 44 41 42 52 41 21 * 0000014 * ******************************************************************************/ /** * The {@code HexDump} class provides a client for displaying the contents * of a binary file in hexadecimal. *
* For additional documentation, * see Section 5.5 of * Algorithms, 4th Edition by Robert Sedgewick and Kevin Wayne. *
* See also {@link BinaryDump} and {@link PictureDump}. * For more full-featured versions, see the Unix utilities * {@code od} (octal dump) and {@code hexdump} (hexadecimal dump). *
* * @author Robert Sedgewick * @author Kevin Wayne */ public class HexDump { // Do not instantiate. private HexDump() { } /** * Reads in a sequence of bytes from standard input and writes * them to standard output using hexadecimal notation, k hex digits * 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 bytesPerLine = 16; if (args.length == 1) { bytesPerLine = Integer.parseInt(args[0]); } int i; for (i = 0; !BinaryStdIn.isEmpty(); i++) { if (bytesPerLine == 0) { BinaryStdIn.readChar(); continue; } if (i == 0) StdOut.printf(""); else if (i % bytesPerLine == 0) StdOut.printf("\n", i); else StdOut.print(" "); char c = BinaryStdIn.readChar(); StdOut.printf("%02x", c & 0xff); } if (bytesPerLine != 0) StdOut.println(); StdOut.println((i*8) + " bits"); } }