// exc7.c   example file  write a file and read a file

#include <stdio.h>  // needed to do input and output

int main(int argc, char *argv[]) // argc is count of command line arguments
                                 // argv is list of command line arguments
{
  char filename[] = "myfile.txt";
  FILE * outp;                   // file handle pointer  
  FILE * inp;
  char line[80];
  
  outp = fopen(filename,"w");
  if(outp == NULL){              // standard test when opening a file
    printf("file %s could not be opened for writing\n",filename);
    return 1;                    // tell user there is a problem
  }
  fprintf(outp, "line 1 \n");
  fprintf(outp, "x=%f, y=%f \n", 1.2, 3.5);
  fprintf(outp, "last line \n");
  fclose(outp);
  printf("exc7.c wrote %s, now read that file \n", filename);

  inp = fopen(filename,"r");
  if(inp == NULL){              // standard test when opening a file
    printf("file %s could not be opened for reading\n",filename);
    return 1;                    // tell user there is a problem
  }
  while(!feof(inp))
  {
    fgets(line, 80, inp);
    printf("%s",line);  // no newline in format, came in from file
    // could use fscanf(inp, "%d", &i); or other format  needs &
  }  
  fclose(inp);
  return 0;
} // end exc7.c   optional comment