#include "stdio.h"
#include "stdlib.h"

int main (void)
{
  FILE* pInFile;
  char szFilename [80];
  int i;
  
  /* open the file for output.  */
  printf ("filename? ");
  scanf ("%s", szFilename);

  /* "w" in the next line means "open for writing" */
  pInFile = fopen (szFilename, "w");
  if (!pInFile)
    {
      fprintf (stderr,"Can't open %s\n",szFilename);
      exit (-1);
    }

  /* print 1 to 10, two-to-a-line to pInFile. */
  for (i = 1; i < 10; i +=2)
    fprintf (pInFile, "%d %d\n", i, i+1);
  
  /* fclose closes a file */
  fclose (pInFile);
  return 0;
}