1#include "stdio_impl.h"
2#include <sys/uio.h>
3
4size_t __stdio_read(FILE *f, unsigned char *buf, size_t len)
5{
6	struct iovec iov[2] = {
7		{ .iov_base = buf, .iov_len = len - !!f->buf_size },
8		{ .iov_base = f->buf, .iov_len = f->buf_size }
9	};
10	ssize_t cnt;
11
12	cnt = syscall(SYS_readv, f->fd, iov, 2);
13	if (cnt <= 0) {
14		f->flags |= F_EOF ^ ((F_ERR^F_EOF) & cnt);
15		return cnt;
16	}
17	if (cnt <= iov[0].iov_len) return cnt;
18	cnt -= iov[0].iov_len;
19	f->rpos = f->buf;
20	f->rend = f->buf + cnt;
21	if (f->buf_size) buf[len-1] = *f->rpos++;
22	return len;
23}
24