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 }
30