1 #include "stdio_impl.h"
2 #include <sys/uio.h>
3
__stdio_write(FILE *f, const unsigned char *buf, size_t len)4 size_t __stdio_write(FILE *f, const unsigned char *buf, size_t len)
5 {
6 struct iovec iovs[2] = {
7 { .iov_base = f->wbase, .iov_len = f->wpos-f->wbase },
8 { .iov_base = (void *)buf, .iov_len = len }
9 };
10 struct iovec *iov = iovs;
11 size_t rem = iov[0].iov_len + iov[1].iov_len;
12 int iovcnt = 2;
13 ssize_t cnt;
14 for (;;) {
15 cnt = write(f->fd, iov[0].iov_base, iov[0].iov_len);
16 if (0 != iov[1].iov_len) cnt += write(f->fd, iov[1].iov_base, iov[1].iov_len);
17 if (cnt == rem) {
18 f->wend = f->buf + f->buf_size;
19 f->wpos = f->wbase = f->buf;
20 return len;
21 }
22 if (cnt < 0) {
23 f->wpos = f->wbase = f->wend = 0;
24 f->flags |= F_ERR;
25 return iovcnt == 2 ? 0 : len-iov[0].iov_len;
26 }
27 rem -= cnt;
28 if (cnt > iov[0].iov_len) {
29 cnt -= iov[0].iov_len;
30 iov++; iovcnt--;
31 }
32 iov[0].iov_base = (char *)iov[0].iov_base + cnt;
33 iov[0].iov_len -= cnt;
34 }
35 }