1 #include "stdio_impl.h"
3 int __underflow(FILE *f)
7 /* Read from buffer (Do we ever get called when this is true??) */
8 if (f->rpos < f->rstop) return *f->rpos;
10 /* Initialize if we're not already reading */
12 /* Fail immediately if unreadable, eof, or error state. */
13 if (f->flags & (F_EOF|F_ERR|F_NORD)) return EOF;
15 /* Set byte orientation -1,0=>-1; 1=>1 */
18 /* Flush any unwritten output; fail on error. */
19 if (f->wpos > f->buf && __oflow(f)) return EOF;
21 /* Disallow writes to buffer. */
25 /* Perform the underlying read operation */
26 if ((cnt=f->read(f, f->buf, f->buf_size)) + 1 <= 1) {
27 /* Set flags and leave read mode */
28 f->flags |= F_EOF | (cnt & F_ERR);
29 f->rpos = f->rend = f->rstop = 0;
33 /* Setup buffer pointers for reading from buffer */
35 f->rend = f->rstop = f->buf + cnt;