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

int main(int argc, char *argv[])
{
  // can handle up to a 8 column, 100000 line array 
  int iter=0, nfound=0, s=0, Nc=8, len=100000, buflen=100, end, i, j ;
  // for the read file section 
         char buffer[buflen], tempbuf[buflen], *junk;       // a variable for the strings we read in
         int counter = 1, reclength, start,recordnum, totalrecs, counter2, working; 
	 double temper, x[Nc][len] ;
	 FILE *inputfile;        // a pointer to the input file
/* set up the initial array , here reading from the file your pointing to in invocation */ 
	 FILE *outputfile;       // a pointer to the output file
         inputfile = fopen(argv[1], "r");        // open input file
         // Before going on, make sure the input file opened properly
         if(inputfile != NULL)
         {
	 outputfile = fopen(argv[3], "w");       // open output file
	   // INPUT SECTION read the header; Nc (number of columns) 
	   //       first, then totalrecs
		 fgets(buffer, buflen, inputfile);      		 
		 Nc=atoi(buffer);
		 fgets(buffer, buflen, inputfile);
		 totalrecs=(int)strtod(buffer, &junk);
		 //printf("number of columns of data is %5i and number of recs in this file is %5i\n", Nc, totalrecs);
		 recordnum=atoi(argv[2]); /*here second argument is where to start reading input file */
		 if(recordnum<0){
		   printf("negative record request");
		   exit(1);
		 };
		 if(recordnum>totalrecs){
		   printf("request is beyond EOF!");
		   exit(1);
		 };
		 //PREPROCESSOR
		 //start=(2*Nv+2)*recordnum; // starting line to read
		 start=recordnum;
		 end=totalrecs-start; 
		 //END OF PREPROCESSOR
		 counter=0;
		 // travel to start
		 while(counter < start) {
		   fgets(buffer, buflen, inputfile);
		   counter++;
		 }
		 printf(" Initial record requested %5i\n",recordnum);
		 // READ FROM START
		 counter=0; //reset counter
		 i=0;
		 while (counter < end){
		   fgets(buffer, buflen, inputfile);
		   counter2=0;
		   j=0;
		   i=0;
		   while (buffer[i] != '\0') 
		     {
		     if (buffer[i]==' ') 
		       { 
			 tempbuf[j]='\0';
			    if (j != 0)
			      { 
		       x[counter2][counter]=strtod(tempbuf, &junk);
		       //printf("%.18e\n", x[counter2][counter]);
		       counter2++;
		       j=0;
			      }
		       }
			 else
			   { tempbuf[j]=buffer[i];
			   j++;
			   }
		     i++;
		     }
		   if (j !=0)
			      {
				tempbuf[j]='\0';
		       x[counter2][counter]=strtod(tempbuf, &junk);
		       //printf("%.18e\n", x[counter2][counter]);
		       counter2++;
		       j=0;
			      } else {}
		   counter++;
		 // THESE NEXT LINES ARE FOR TESTING THE READIN..POSTPROCESSING
		   /* if (x[counter]*x[counter]+y[counter]*y[counter]+lambda*lambda > rtf0*rtf0) 
		     {
		       mask[counter]=0.;
		       }else(mask[counter]=1.0); */
		 // END OF POST PROCESSING THE READ. 
		 }
		 // close the file
                 fclose(inputfile);
	 }
         else (printf("Error opening input file.\n"));
	 // MAIN PROCESSING PROGRAM GOES HERE! 


	 // END OF MAIN PROCESSING PROGRAM
        
  //Write out to the data file section 
	 counter=0;
	 while (counter< end)
	   { 
	     //working=sprintf(buffer, 100,  "%d", x[1][counter]);
	     fprintf(outputfile, "%8.3f\n", x[1][counter]);
	     counter++;
	   }
  fclose(outputfile); 
  //end of writeout section 
  return 0;
}