Hexdump.cs

/* Hexdump.cs
 * A simple command-line Hex dumper
 *
 * Copyright (c) 2016 Rubyist
 * This work is free. You can redistribute it and/or modify it under the
 * terms of the Do What The Fuck You Want To Public License, Version 2,
 * as published by Sam Hocevar. See http://www.wtfpl.net/ for more details.
 */

using System;
using System.IO;

public class Hexdump
{
    public static void Main(String[] args)
    {
        /* Print usage information */
        if (args.Length != 1)
        {
            Usage();
        }

        if (args[0] == "--help" || args[0] == "-h")
        {
            Usage();
        }

        /* Open and dump file */
        try
        {
            FileStream file = File.Open(args[0], FileMode.Open);
            DumpFile(file);
            file.Close();
        }
        catch (Exception)
        {
            Console.WriteLine("Could not open file");
            Environment.Exit(-1);
        }


    }

    static void PrintAscii(byte[] buffer, int len)
    {
        /* Print excess spaces for last line of a hex dump */
        if (len < 16)
        {
            int spaces = (((16 - len) * 5) / 2) + (len % 2);
            for (int i = 0; i < spaces; i++)
            {
                Console.Write(' ');
            }
        }

        /* Print ascii values of all non-whitespace 7-bit ascii chars */
        for (int i = 0; i < len; i++)
        {
            if (buffer[i] < 32 || buffer[i] > 126)
            {
                Console.Write('.');
            }
            else
            {
                Console.Write(Convert.ToChar(buffer[i]));
            }
        }
    }

    static void Usage()
    {
        Console.WriteLine("usage: Hexdump binfile");
        Environment.Exit(0);
    }

    static void DumpFile(FileStream file)
    {
        /* Write header */
        Console.WriteLine(
            "Offset:             " +
            "Bytes:                                  " +
            "ASCII:"
        );

        /* Write the following information:
         * Offset: 64 bit value represented in hex.
         * Bytes: 8 groups of 2 bytes each, represented as 4 hex digits.
         * ASCII: 7-bit ascii interpretation of data. Whitespace are '.'
         */
        byte[] buffer = new byte[16];
        while (file.Position != file.Length)
        {
            Console.Write("0x{0}: ", file.Position.ToString("X16"));
            int written = file.Read(buffer, 0, 16);
            for (int i = 0; i < written; i++)
            {
                Console.Write(buffer[i].ToString("X2"));
                if (i%2 == 1)
                {
                    Console.Write(' ');
                }
            }
            PrintAscii(buffer, written);
            Console.WriteLine("");
        }
    }
}