/* VERIFY.C - Verify encoded or decoded blocks. *//* Copyright (c) 2000, 2001 by Radford M. Neal  * * Permission is granted for anyone to copy, use, or modify this program  * for purposes of research or education, provided this copyright notice  * is retained, and note is made of any changes that have been made.  * * This program is distributed without any warranty, express or implied. * As this program was written for research purposes only, it has not been * tested to the degree that would be advisable in any important application. * All use of this program is entirely at the user's own risk. */#include <stdio.h>#include <stdlib.h>#include <string.h>#include <math.h>#include "alloc.h"#include "blockio.h"#include "open.h"#include "mod2sparse.h"#include "mod2dense.h"#include "mod2convert.h"#include "rcode.h"#include "check.h"void usage(void);/* MAIN PROGRAM. */int main( int argc,  char **argv){  char *coded_file, *source_file;  char *pchk_file, *gen_file;  int table;  char *sblk, *cblk, *chks;  int seof, ceof;  int srcerr, chkerr, bit_errs;  int i, n;  FILE *srcf, *codef;  int tot_srcerrs, tot_chkerrs, tot_botherrs;  /* Look at arguments. */  table = 0;  if (argc>1 && strcmp(argv[1],"-t")==0)  { table = 1;    argc -= 1;    argv += 1;  }  if (argc<3 || argc>5) usage();  if (!(pchk_file = argv[1])   || !(coded_file = argv[2]))  { usage();  }   gen_file = 0;  source_file = 0;  if (argv[3])  { gen_file = argv[3];    if (argv[4])    { source_file = argv[4];      if (argv[5])      { usage();      }    }  }  if ((strcmp(pchk_file,"-")==0)     + (strcmp(coded_file,"-")==0)     + (source_file!=0 && strcmp(source_file,"-")==0)    + (gen_file!=0 && strcmp(gen_file,"-")==0) > 1)  { fprintf(stderr,"Can't read more than one stream from standard input\n");    exit(1);  }  /* Read parity check file. */  read_pchk(pchk_file);  if (N<=M)  { fprintf(stderr,     "Number of bits (%d) should be greater than number of checks (%d)\n",N,M);    exit(1);  }  /* Read generator matrix file, if given, up to the point of finding     out which are the message bits. */  if (gen_file!=0)  { read_gen(gen_file,1,0);  }  /* Open coded file to check. */  codef = open_file_std(coded_file,"r");  if (codef==NULL)  { fprintf(stderr,"Can't open coded file: %s\n",coded_file);    exit(1);  }  /* Open source file to verify against, if given. */  if (source_file!=0)  {     srcf = open_file_std(source_file,"r");    if (srcf==NULL)    { fprintf(stderr,"Can't open source file: %s\n",source_file);      exit(1);    }  }  sblk = chk_alloc (N-M, sizeof *sblk);  cblk = chk_alloc (N, sizeof *cblk);  chks = chk_alloc (M, sizeof *chks);  /* Print header for table. */  if (table)  { if (gen_file!=0)    { printf("  block chkerrs srcerrs\n");    }    else    { printf("  block chkerrs\n");    }  }  /* Verify successive blocks. */  tot_srcerrs = 0;  tot_chkerrs = 0;  tot_botherrs = 0;  bit_errs = 0;  seof = 0;   ceof = 0;  for (n = 0; ; n++)  {     /* Read block from coded file. */        if (blockio_read(codef,cblk,N)==EOF)     { ceof = 1;    }    /* Read block from source file, if given. */    if (source_file!=0 && !ceof && !seof)    { if (blockio_read(srcf,sblk,N-M)==EOF)       { fprintf(stderr,"Warning: Not enough source blocks (only %d)\n",n);        seof = 1;      }    }    /* Stop if end of received file. */    if (ceof) break;    /* Check that received block is a code word, and if not find the number of       parity check errors. */    chkerr = check(H,cblk,chks);    /* Check against source block, if provided, or against zeros, if       the generator matrix was provided but no source file. */    if (gen_file!=0)    { srcerr = 0;      if (source_file!=0 && !seof)      { for (i = M; i<N; i++)        { if (cblk[cols[i]]!=sblk[i-M])          { srcerr += 1;          }        }      }      if (source_file==0)      { for (i = M; i<N; i++)        { if (cblk[cols[i]]!=0)          { srcerr += 1;          }        }      }      bit_errs += srcerr;    }    /* Print table entry. */    if (table)    { if (gen_file!=0)      { printf("%6d %7d %7d\n",n,chkerr,srcerr);      }      else      { printf("%6d %7d\n",n,chkerr);      }    }    /* Increment totals. */    if (chkerr) tot_chkerrs += 1;    if (gen_file!=0 && (source_file==0 || !seof))    { if (srcerr) tot_srcerrs += 1;      if (srcerr && chkerr) tot_botherrs += 1;    }  }  /* Write final statistics to standard error.  Flush standard output      first to avoid mixing of output. */  fflush(stdout);  if (gen_file!=0)  { fprintf(stderr,     "Block counts: tot %d, with chk errs %d, with src errs %d, both %d\n",      n, tot_chkerrs, tot_srcerrs, tot_botherrs);    fprintf(stderr,     "Bit error rate (on message bits only): %.3e\n",       (double)bit_errs/(n*(N-M)));  }  else  { fprintf (stderr,      "Block counts: tot %d, with chk errs %d\n", n, tot_chkerrs);  }  return 0;}/* PRINT USAGE MESSAGE AND EXIT. */void usage(void){ fprintf(stderr, "Usage: verify [ -t ] pchk-file decoded-file [ gen-file [ source-file ] ]\n");  exit(1);}