edu.princeton.cs.algs4.HexDump Maven / Gradle / Ivy
/******************************************************************************
* 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
*
******************************************************************************/
package edu.princeton.cs.algs4;
/**
* 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 hexademical 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");
}
}
/******************************************************************************
* Copyright 2002-2018, Robert Sedgewick and Kevin Wayne.
*
* This file is part of algs4.jar, which accompanies the textbook
*
* Algorithms, 4th edition by Robert Sedgewick and Kevin Wayne,
* Addison-Wesley Professional, 2011, ISBN 0-321-57351-X.
* http://algs4.cs.princeton.edu
*
*
* algs4.jar is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* algs4.jar is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with algs4.jar. If not, see http://www.gnu.org/licenses.
******************************************************************************/