printf

/*
 *  call-seq:
 *     ios.printf(format_string [, obj, ...] )   => nil
 *  
 *  Formats and writes to <em>ios</em>, converting parameters under
 *  control of the format string. See <code>Kernel#sprintf</code>
 *  for details.
 */

VALUE
rb_io_printf(argc, argv, out)
    int argc;
    VALUE argv[];
    VALUE out;
{
    rb_io_write(out, rb_f_sprintf(argc, argv));
    return Qnil;
}