| 1 | #include "stdio_impl.h" |
| 2 | |
| 3 | /* The behavior of this function is undefined except when it is the first |
| 4 | * operation on the stream, so the presence or absence of locking is not |
| 5 | * observable in a program whose behavior is defined. Thus no locking is |
| 6 | * performed here. No allocation of buffers is performed, but a buffer |
| 7 | * provided by the caller is used as long as it is suitably sized. */ |
| 8 | |
| 9 | int setvbuf(FILE *restrict f, char *restrict buf, int type, size_t size) |
| 10 | { |
| 11 | f->lbf = EOF; |
| 12 | |
| 13 | if (type == _IONBF) { |
| 14 | f->buf_size = 0; |
| 15 | } else if (type == _IOLBF || type == _IOFBF) { |
| 16 | if (buf && size >= UNGET) { |
| 17 | f->buf = (void *)(buf + UNGET); |
| 18 | f->buf_size = size - UNGET; |
| 19 | } |
| 20 | if (type == _IOLBF && f->buf_size) |
| 21 | f->lbf = '\n'; |
| 22 | } else { |
| 23 | return -1; |
| 24 | } |
| 25 | |
| 26 | f->flags |= F_SVB; |
| 27 | |
| 28 | return 0; |
| 29 | } |