#include "stdio_impl.h"
+#include <wchar.h>
+#include <limits.h>
+#include <ctype.h>
+#include <string.h>
wint_t ungetwc(wint_t c, FILE *f)
{
f->mode |= f->mode+1;
- /* Fail if unreadable or writing and unable to flush */
- if ((f->flags & (F_ERR|F_NORD)) || (f->wpos && __oflow(f))) {
+ if ((!f->rend && __toread(f)) || f->rpos < f->buf - UNGET + l) {
FUNLOCK(f);
return EOF;
}
- /* Clear write mode */
- f->wpos = f->wstop = f->wend = 0;
-
- /* Put the file in read mode */
- if (!f->rpos) f->rpos = f->rend = f->buf;
-
- /* If unget buffer is nonempty, fail. */
- if (f->rpos < f->buf) {
- FUNLOCK(f);
- return WEOF;
- }
-
- /* Put character back into the buffer */
if (isascii(c)) *--f->rpos = c;
else memcpy(f->rpos -= l, mbc, l);
- /* Clear EOF */
f->flags &= ~F_EOF;
FUNLOCK(f);