/*  crc_prb.c */

#include <stdlib.h>
#include <stdio.h>

#include "crc.h"

void main ( void );

void test01 ( void );
void test02 ( void );
void test03 ( void );

/******************************************************************************/

void main ( void )

/******************************************************************************/
{
  printf ( "\n" );
  printf ( "CRC_PRB\n");
  printf ( "  Test CRC routines.\n");

  test01 ( );
  test02 ( );
  test03 ( );

  printf ( "\n" );
  printf ( "CRC_PRB\n");
  printf ( "  Normal end of CRC tests.\n");

  exit;
}
/**********************************************************************/

void test01 ( void )

/**********************************************************************/

/*
  TEST01 tests MAKE_CRC_TABLE.
*/
{
  int i;

  printf ( "\n" );
  printf ( "TEST01\n" );
  printf ( "  MAKE_CRC_TABLE sets up the 256 entry CRC table.\n" );
  printf ( "\n" );
  printf ( "  Each entry is an unsigned long integer.  We'll print\n" );
  printf ( "  signed versions of the entries.\n" );

  make_crc_table();

  print_crc_table();

  return;
}
/**********************************************************************/

void test02 ( void )

/**********************************************************************/

/*
  TEST02 tests CRC.
*/
{
  unsigned char buf[10];
  unsigned char c;
  int len = 10;
  unsigned long my_crc;
/*
  How do I assign these more simply?
  How do I print a string of 10 characters?
  How do I do the CRC for, say, an integer vector?
*/
  buf[0] = 'D';
  buf[1] = 'r';
  buf[2] = '.';
  buf[3] = ' ';
  buf[4] = 'C';
  buf[5] = 'r';
  buf[6] = 'y';
  buf[7] = 'p';
  buf[8] = 't';
  buf[9] = 'o';

  printf ( "\n" );
  printf ( "TEST02\n" );
  printf ( "  CRC computes the CRC of a string of bytes.\n" );
  printf ( "\n" );

  my_crc = crc ( buf, len );
  printf ( "\n" );
  printf ( "  Original CRC                     = %x (hex).\n", my_crc );
  printf ( "                                   = %d (dec).\n", my_crc );

  c = buf[3];
  buf[3] = buf[4];
  buf[4] = c;

  my_crc = crc ( buf, len );
  printf ( "\n" );
  printf ( "  CRC after swapping C[3] and C[4] = %x (hex).\n", my_crc );
  printf ( "                                   = %d (dec).\n", my_crc );

  c = buf[3];
  buf[3] = buf[4];
  buf[4] = c;

  buf[5] = buf[5] + 1;

  my_crc = crc ( buf, len );
  printf ( "\n" );
  printf ( "  CRC after incrementing C[5] by 1 = %x (hex).\n", my_crc );
  printf ( "                                   = %d (dec).\n", my_crc );

  my_crc = crc ( buf, len-1 );
  printf ( "\n" );
  printf ( "  CRC of first LEN-1 values        = %x (hex).\n", my_crc );
  printf ( "                                   = %d (dec).\n", my_crc );

  return;
}
void test03 ( void )

/**********************************************************************/

/*
  TEST03 tests UPDATE_CRC.
*/
{
  unsigned char buf[10];
  int i;
  int len = 10;
  unsigned long my_crc;
/*
  How do I assign these more simply?
  How do I print a string of 10 characters?
  How do I do the CRC for, say, an integer vector?
*/
  buf[0] = 'D';
  buf[1] = 'r';
  buf[2] = '.';
  buf[3] = ' ';
  buf[4] = 'C';
  buf[5] = 'r';
  buf[6] = 'y';
  buf[7] = 'p';
  buf[8] = 't';
  buf[9] = 'o';

  printf ( "\n" );
  printf ( "TEST03\n" );
  printf ( "  UPDATE_CRC computes the running CRC of a string of bytes.\n" );
  printf ( "  This should be the same as computing the full CRC.\n" );
  printf ( "\n" );

  my_crc = crc ( buf, len );
  printf ( "\n" );
  printf ( "  Full CRC                     = %x (hex).\n", my_crc );
  printf ( "                               = %d (decimal).\n", my_crc );

  my_crc = 0xffffffffL;
  for ( i = 0; i < len; i++ ) {
    my_crc = update_crc ( my_crc, &buf[i], 1 );
  }
  my_crc = my_crc ^ 0xffffffffL;

  printf ( "\n" );
  printf ( "  Incremental CRC              = %x (hex).\n", my_crc );
  printf ( "                               = %d (decimal).\n", my_crc );

  return;
}