#include "shgetc.h"
+/* The shcnt field stores the number of bytes read so far, offset by
+ * the value of buf-rpos at the last function call (__shlim or __shgetc),
+ * so that between calls the inline shcnt macro can add rpos-buf to get
+ * the actual count. */
+
void __shlim(FILE *f, off_t lim)
{
f->shlim = lim;
- f->shcnt = f->rend - f->rpos;
- if (lim && f->shcnt > lim)
+ f->shcnt = f->buf - f->rpos;
+ /* If lim is nonzero, rend must be a valid pointer. */
+ if (lim && f->rend - f->rpos > lim)
f->shend = f->rpos + lim;
else
f->shend = f->rend;
int __shgetc(FILE *f)
{
int c;
- if (f->shlim && f->shcnt >= f->shlim || (c=__uflow(f)) < 0) {
- f->shend = 0;
+ off_t cnt = shcnt(f);
+ if (f->shlim && cnt >= f->shlim || (c=__uflow(f)) < 0) {
+ f->shcnt = f->buf - f->rpos + cnt;
+ f->shend = f->rpos;
+ f->shlim = -1;
return EOF;
}
- if (f->shlim && f->rend - f->rpos > f->shlim - f->shcnt - 1)
- f->shend = f->rpos + (f->shlim - f->shcnt - 1);
+ cnt++;
+ if (f->shlim && f->rend - f->rpos > f->shlim - cnt)
+ f->shend = f->rpos + (f->shlim - cnt);
else
f->shend = f->rend;
- if (f->rend) f->shcnt += f->rend - f->rpos + 1;
- if (f->rpos[-1] != c) f->rpos[-1] = c;
+ f->shcnt = f->buf - f->rpos + cnt;
+ if (f->rpos <= f->buf) f->rpos[-1] = c;
return c;
}