/*
** hexdump.c - Program to dump the contents of a file to hexadecimal
**
** File created:  8/8/2000
** Last revision: 8/10/2000
**
** Copyright (C) 2000	Sean R. Wells <swells@gmu.edu>
**
** This program 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 2 of the License, or
** (at your option any later version.
**
** This program 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 this program; if not, write to the Free Software
** Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
**
*/
#include <stdio.h>

typedef struct arg_info {
  FILE *infile;
  int width;
  int suppress_offset;
  int suppress_text;
} arg_info;

int InitializeArgs ( arg_info *arguments )
{
  ( *arguments ).width = 16;
  ( *arguments ).suppress_offset = 0;
  ( *arguments ).suppress_text = 0;

  return ( 0 );
}

int ProcessArgs ( int argc, char **argv, arg_info *arguments )
{
  register FILE *input_file;
  int i;

  if ( argc < 2 ) {
    fprintf ( stderr, "hexdump version 1.0b Copyright (C) 2000 Sean R. Wells\n");
    fprintf ( stderr, "Usage: hexdump <filename> [-w #columns] [-st] [so]\n" );
    fprintf ( stderr, "	-w #columns	sets the width of the output\n" );
    fprintf ( stderr, "	-st		suppresses the text interpretation\n" );
    fprintf ( stderr, "	-so		suppresses printing of offset\n" );
    return ( -1 );
  }

  input_file = fopen ( argv[1], "rb" );

  if ( !input_file ) {
    fprintf ( stderr, "ERROR - could not open input file\n" );
    return ( -1 );
  }

  ( *arguments ).infile = input_file;

  for ( i = 2; i < argc; i++ ) {
    if ( ( strcmp ( argv[i], "-w" ) == 0 ) && ( argc > i ) ) {
      ( *arguments ).width = atoi ( argv[i+1] );
    }
    if ( strcmp ( argv[i], "-so" ) == 0 ) {
      ( *arguments ).suppress_offset = 1;
    }
    if ( strcmp ( argv[i], "-st" ) == 0 ) {
      ( *arguments ).suppress_text = 1;
    }
  }

  return ( 0 );

}


int DumpFile ( arg_info arguments )
{
  int i, i2;
  int ch;
  unsigned char text_conv[128];
  long int file_size = 0;

  ch = getc ( arguments.infile );
  while ( ch != EOF ) {
    if ( arguments.suppress_offset == 0 ) printf ( "0x%3x   ", file_size );
    for ( i = 0; ( i < arguments.width ) && ( ch != EOF ); i++ ) {
      if ( ( unsigned char ) ch < 16 ) printf ( "0" );
      printf ( "%x ", ( unsigned char ) ch );
      if ( ch > 31 ) text_conv[i] = ( unsigned char ) ch;
      else text_conv[i] = '.';
      text_conv[i+1] = '\0';
      ch = getc ( arguments.infile );
      file_size++;
    }
    for ( i2 = i; i2 < arguments.width; printf ( "   " ), i2++ ); 

    if ( arguments.suppress_text == 0 ) printf ( "%s", text_conv );
    printf ( "\n" );
  }

  fclose ( arguments.infile );

  return ( 0 );
}

int main ( argc, argv )
           int argc;
           char **argv;
{
  long int file_size = 0;
  arg_info arguments;

  InitializeArgs ( &arguments );
  if ( ProcessArgs ( argc, argv, &arguments ) == -1 ) return ( 0 );
  file_size = DumpFile ( arguments );

  return ( 0 );
}