| 1 | #include "stdio_impl.h" |
| 2 | |
| 3 | int ungetc(int c, FILE *f) |
| 4 | { |
| 5 | if (c == EOF) return c; |
| 6 | |
| 7 | FLOCK(f); |
| 8 | |
| 9 | if (!f->rpos) __toread(f); |
| 10 | if (!f->rpos || f->rpos <= f->buf - UNGET) { |
| 11 | FUNLOCK(f); |
| 12 | return EOF; |
| 13 | } |
| 14 | |
| 15 | *--f->rpos = c; |
| 16 | f->flags &= ~F_EOF; |
| 17 | |
| 18 | FUNLOCK(f); |
| 19 | return (unsigned char)c; |
| 20 | } |