// $Header: /cvsroot/esrg/sfesrg/esrgpcpj/crc32/c_main.c,v 1.5 2002/05/23 01:32:22 dtashley Exp $

//--------------------------------------------------------------------------------
//Copyright 2001 David T. Ashley
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//IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
//ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
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//  16. Limitation of Liability.
//
//  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
//WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
//THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
//GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
//USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
//DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
//PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
//EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
//SUCH DAMAGES.
//
//  17. Interpretation of Sections 15 and 16.
//
//  If the disclaimer of warranty and limitation of liability provided
//above cannot be given local legal effect according to their terms,
//reviewing courts shall apply local law that most closely approximates
//an absolute waiver of all civil liability in connection with the
//Program, unless a warranty or assumption of liability accompanies a
//copy of the Program in return for a fee.
//
//                     END OF TERMS AND CONDITIONS
//
//            How to Apply These Terms to Your New Programs
//
//  If you develop a new program, and you want it to be of the greatest
//possible use to the public, the best way to achieve this is to make it
//free software which everyone can redistribute and change under these terms.
//
//  To do so, attach the following notices to the program.  It is safest
//to attach them to the start of each source file to most effectively
//state the exclusion of warranty; and each file should have at least
//the "copyright" line and a pointer to where the full notice is found.
//
//    <one line to give the program's name and a brief idea of what it does.>
//    Copyright (C) <year>  <name of author>
//
//    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 3 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, see <http://www.gnu.org/licenses/>.
//
//Also add information on how to contact you by electronic and paper mail.
//
//  If the program does terminal interaction, make it output a short
//notice like this when it starts in an interactive mode:
//
//    <program>  Copyright (C) <year>  <name of author>
//    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
//    This is free software, and you are welcome to redistribute it
//    under certain conditions; type `show c' for details.
//
//The hypothetical commands `show w' and `show c' should show the appropriate
//parts of the General Public License.  Of course, your program's commands
//might be different; for a GUI interface, you would use an "about box".
//
//  You should also get your employer (if you work as a programmer) or school,
//if any, to sign a "copyright disclaimer" for the program, if necessary.
//For more information on this, and how to apply and follow the GNU GPL, see
//<http://www.gnu.org/licenses/>.
//
//  The GNU General Public License does not permit incorporating your program
//into proprietary programs.  If your program is a subroutine library, you
//may consider it more useful to permit linking proprietary applications with
//the library.  If this is what you want to do, use the GNU Lesser General
//Public License instead of this License.  But first, please read
//<http://www.gnu.org/philosophy/why-not-lgpl.html>.
//-------------------------------------------------------------------------------------------------
//--------------------------------------------------------------------------------
#include <assert.h>
#include <process.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>


#include "ccmalloc.h"
#include "crchashfuncs.h"
#include "cu_msgs.h"
#include "fcmiof.h"


#define PNAME "crc32"
#define PNAMEUC "CRC32"


const char *C_MAIN_cvcinfo(void)
   {
   return("$Header: /cvsroot/esrg/sfesrg/esrgpcpj/crc32/c_main.c,v 1.5 2002/05/23 01:32:22 dtashley Exp $");
   }


//This is a NULL-terminated table of pointers to functions
//which return version control strings for all of the files
//which make up the INTFAC program.  This information would
//be helpful for debugging.
static const char *(*C_MAIN_vcinfoptrs[])(void) =
   {
   //This is the main module, should come first.
   C_MAIN_cvcinfo,

   //And now the others, in alphabetical order.
   CRCHASHFUNCS_hvcinfo,
   CRCHASHFUNCS_cvcinfo,
   CU_MSGS_hvcinfo,
   CU_MSGS_cvcinfo,
   FCMIOF_hvcinfo,
   FCMIOF_cvcinfo,
   NULL
   };



#define CRC32CMAIN_BUFSIZE  (131072)
   //This value is the size of the buffer that is used when
   //reading from a file and computing CRC.  At the time of
   //this writing (2001) a typical cluster size is 32K (not
   //that I know what a cluster is).  I suspect that this
   //is a fairly efficient value.  In any case, I believe the
   //value should be a power of two, because any lower power
   //of two will fill it evenly with no leftover.

static unsigned char CRC32MAIN_buf[CRC32CMAIN_BUFSIZE];
   //I suspect that allocating the buffer so it is ready at
   //load time is quicker than doing a dynamic allocation.
   //This is the buffer used for reading file blocks.


//Dumps the filesize to stdout.  This has a small amount of
//complexity.
void CRC32MAIN_dump_filesize(unsigned _int64 filesize, int commas)
   {
   char buf[100];
   int len, i;

   _ui64toa(filesize, buf, 10);
   len = strlen(buf);

   for (i=0; i<len; i++)
      {
      printf("%c", buf[i]);
      if (commas && (i!=len-1) && ((len-i) % 3 == 1))
         printf(",");
      }
   }


int c_main(int argc, char* argv[])
   {
   int rv=0;
      //Function return value.
   int i;
      //Iteration variable.
   FILE *fptr = NULL;
      //Pointer to open stream.
   size_t bytes_read;
      //Bytes read from fread() call.
   struct CRCHASHFUNCS_Crc32StateStruct crcgen;
      //State vector for CRC generation.
   unsigned crc;
      //The actual CRC.
   unsigned _int64 filesize = 0;
      //The file size, calculated by adding up the numbers of characters read.
   CU_MSGS_std_cmd_line_par_results_struct argblock;
      //Used to hold results of what is found on command-line.

   if (argc < 2)
      {
      CU_MSGS_too_few_args_msg(stdout, PNAME);
      rv = 4;
      goto ret_pt;
      }
   else if (argc==2 && !strcmp(argv[1], "-help"))
      {
      FCMIOF_hline();
      printf("DESCRIPTION\n");
      printf("   This program calculates the CRC-32 and file size (in bytes) of a file.\n");
      printf("   The CRC-32 is calculated using code obtained from a website maintained by\n");
      printf("   Richard A. Ellingson.  The file size is calculated using the sum of the\n");
      printf("   sizes of file reads used to obtain data in order to calculate the CRC-32.\n");
      printf("   In all cases this file size should be the same as the size maintained by\n");
      printf("   the operating system.  The CRC-32 is provided in hexadecimal, and the\n");
      printf("   file size is provided in base-10.\n");
      printf("\n");
      printf("   The CRC-32 is especially useful for digitally \"signaturing\" files.  If the\n");
      printf("   CRC-32 and file size of two files are the same, the probability is probably\n");
      printf("   greater than 1-pow(2,-32) (>0.9999999997) that the two files have the same\n");
      printf("   contents.\n");
      printf("\n");
      printf("USAGE\n");
      printf("   crc32 fname [options]\n");
      printf("   crc32 -help\n");
      printf("\n");
      printf("OPTIONS\n");
      CU_MSGS_std_options(stdout, PNAME);
      FCMIOF_hline();
      CU_MSGS_toolset_info_msg(stdout, PNAME);
      FCMIOF_hline();
      }
   else
      {
      //Analyze the remainder of the parameters on the command line.  These must be
      //"standard" parameters.
      //We have a valid integer.  
      //Take a peek at the command-line arguments.
      CU_MSGS_cmd_line_par_results_struct_create(&argblock);

      for (i=2; i<argc; i++)
         {
         int recognized;

         CU_MSGS_cmd_line_par_results_struct_process_arg(&argblock,
                                                         argv[i],
                                                         &recognized);
         if (!recognized)
            {
            printf("\"%s\" is not a recognized command-line parameter.\n", argv[i]);
            rv = 4;
            goto ret_pt;
            }
         else if (argblock.help)
            {
            printf("\"-help\" cannot appear in this position.\n");
            rv = 4;
            goto ret_pt;
            }
         }

      //Clean up the interpretation of the command-line arguments.
      CU_MSGS_cmd_line_par_results_struct_finalize(&argblock);

      //If we are in debug mode, we want to output the version 
      //of all of the software components making up this program,
      //except the calling .CPP file, which is trivial and 
      //could not cause a bug.  The called function will not
      //output any horizontal lines, so must handle those
      //manually.
      if (argblock.debug)
         {
         FCMIOF_hline();
         CU_MSGS_emit_vcinfo_from_ptr_table(stdout,C_MAIN_vcinfoptrs,PNAMEUC);
         FCMIOF_hline();
         }

      //Look at the CRC32 generation table.  In debug mode, fail if it is not right.
      i=CRCHASHFUNCS_Crc32TableCheck();
      assert(i);
      if (!i && argblock.debug)
         {
         printf("WARNING:  CRC32 table corrupted.\n");
         FCMIOF_hline();
         }

      //Initialize the CRC32 structure.
      CRCHASHFUNCS_Crc32StateStructOpen(&crcgen);

      //Try to open the file for reading in binary mode.
      //Failure is, of course, fatal.
      fptr = fopen(argv[1], "rb");
      if (!fptr)
         {
         printf("fopen() failure.  Most likely cause is file does not exist.\n");
         rv = 4;
         goto ret_pt;
         }

      //Loop through, filling the buffer, doing the CRC calculations,
      //until end of file or error.
      while(!feof(fptr))
         {
         bytes_read = fread(CRC32MAIN_buf, 1, CRC32CMAIN_BUFSIZE, fptr);

         filesize += (unsigned _int64) bytes_read;

         if (ferror(fptr))
            {
            printf("fread() error.\n");
            rv = 4;
            goto ret_pt;
            }

         CRCHASHFUNCS_Crc32StateStructAddData(&crcgen, CRC32MAIN_buf, bytes_read);
         }

      crc = CRCHASHFUNCS_Crc32Extract(&crcgen);
       
      CRCHASHFUNCS_Crc32StateStructClose(&crcgen);

      if (!argblock.noformat)
         printf("0x");
      printf("%08X", crc);
      if (argblock.noformat)
         printf("\n");
      else
         printf(" (");

      CRC32MAIN_dump_filesize(filesize, !argblock.noformat);

      if (!argblock.noformat)
         printf(")");
      printf("\n");
      }

   ret_pt:
   if (fptr)
      fclose(fptr);
   return(rv);
   }


//**************************************************************************
// $Log: c_main.c,v $
// Revision 1.5  2002/05/23 01:32:22  dtashley
// Missing fclose() corrected.
//
// Revision 1.4  2002/01/27 17:58:15  dtashley
// CRC32, other programs modified to work under new directory structure.
//
// Revision 1.3  2001/07/26 23:42:15  dtashley
// Minor documentation touchups.
//
// Revision 1.2  2001/07/26 21:41:20  dtashley
// Completion of CRC32 utility, and the CRCHASHFUNCS module.
//
// Revision 1.1  2001/07/26 04:55:48  dtashley
// Addition of CRC32 and MD5 command-line utilities.  Addition of
// software module to support CRC and HASH functions.
//**************************************************************************
// End of C_MAIN.C.