1#include "shgetc.h"
2
3void __shlim(FILE* f, off_t lim) {
4    f->shlim = lim;
5    f->shcnt = f->rend - f->rpos;
6    if (lim && f->shcnt > lim)
7        f->shend = f->rpos + lim;
8    else
9        f->shend = f->rend;
10}
11
12int __shgetc(FILE* f) {
13    int c;
14    if ((f->shlim && f->shcnt >= f->shlim) || (c = __uflow(f)) < 0) {
15        f->shend = 0;
16        return EOF;
17    }
18    if (f->shlim && f->rend - f->rpos > f->shlim - f->shcnt - 1)
19        f->shend = f->rpos + (f->shlim - f->shcnt - 1);
20    else
21        f->shend = f->rend;
22    if (f->rend)
23        f->shcnt += f->rend - f->rpos + 1;
24    if (f->rpos[-1] != c)
25        f->rpos[-1] = c;
26    return c;
27}
28