+
+extern int _doprnt();
+
+/*VARARGS2*/
+int
+vfprintf(iop, format, ap)
+FILE *iop;
+char *format;
+va_list ap;
+{
+ register int count;
+
+ if (!(iop->_flag | _IOWRT)) {
+ /* if no write flag */
+ if (iop->_flag | _IORW) {
+ /* if ok, cause read-write */
+ iop->_flag |= _IOWRT;
+ } else {
+ /* else error */
+ return EOF;
+ }
+ }
+ count = _doprnt(format, ap, iop);
+ return(ferror(iop)? EOF: count);
+}