fprintf

#include <stdio.h>

int fprintf (
  FILE *stream,             /* file stream to write to */
  const char *fmtstr        /* format string */
  « , arguments ... »);     /* additional arguments */

The fprintf function formats a series of strings and numeric values and writes the resulting string to stream. The fmtstr argument is a pointer to a format string which has the same form and function as the printf function's format string. The list of arguments are converted and output according to the corresponding format specifications in fmtstr.

The fprintf function is in the RL-FlashFS library. The prototype is defined in stdio.h.

#include <rtl.h>
#include <stdio.h>

void tst_fprintf (void) {
   FILE *fout;
   int i = 56;

   fout = fopen ("Test.txt","w");
   if (fout == NULL) {
      printf ("File open error!\n");
   }
   else {
      fprintf (fout, "printf test: val = %i fval =%f\n", i, i * 3.45);
      fclose (fout);
   }
}