/* RAND-SRC.C - Generate random message bits. *//* 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 <math.h>#include "open.h"#include "rand.h"void usage(void);/* MAIN PROGRAM. */int main( int argc,  char **argv){  int seed, bs, nb;  char *file, *n_bits;  char junk;  int i, j;  FILE *f;  if (!(file = argv[1])   || !argv[2] || sscanf(argv[2],"%d%c",&seed,&junk)!=1   || !(n_bits = argv[3])   || argv[4])  { usage();  }  if (sscanf(n_bits,"%d%c",&nb,&junk)==1)  { if (nb<=0) usage();    bs = 1;  }  else if (sscanf(n_bits,"%dx%d%c",&bs,&nb,&junk)==2)  { if (nb<=0 || bs<=0) usage();  }  else  { usage();  }  f = open_file_std(file,"w");  if (f==NULL)  { fprintf(stderr,"Can't create source file: %s\n",file);    exit(1);  }  rand_seed(10*seed+2);  for (i = 0; i<nb; i++)  { for (j = 0; j<bs; j++)    { fprintf(f,"%d",rand_int(2));    }    fprintf(f,"\n");  }  if (ferror(f) || fclose(f)!=0)   { fprintf(stderr,"Error writing random source blocks to %s\n",file);    exit(1);  }  return 0;}/* PRINT USAGE MESSAGE AND EXIT. */void usage(void){ fprintf(stderr,"Usage: rand-src source-file seed n-bits\n");  exit(1);}