#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid
[] = "@(#)ungetc.c 5.3 (Berkeley) %G%";
#endif LIBC_SCCS and not lint
if (c
== EOF
|| (iop
->_flag
& (_IOREAD
|_IORW
)) == 0 ||
iop
->_ptr
== NULL
|| iop
->_base
== NULL
)
if (iop
->_ptr
== iop
->_base
)