#include <stdio.h>
FILE *in;
void readn11_(op,opt,nsize,ibuf,  rtcode)
int *op, *opt, *nsize, ibuf[], *rtcode;
{
  char infile[44];
  if (*op==0)
   {printf("input  file ---->\n");
    scanf("%s",&infile);
    printf("%s\n",infile);
    in = fopen (infile,"r");
    if(in==NULL)
      {printf("file not found\n");      
        *rtcode=999;
       }
      else *rtcode = 0;
   }
   else
   {*rtcode = fread (ibuf,4,*nsize,in);
    if (*rtcode==0) fclose (in);
   }
}