#include "substdio.h"#include "byte.h"#include "error.h"static int oneread(op,fd,buf,len)register int (*op)();register int fd;register char *buf;register int len;{  register int r;  for (;;) {    r = op(fd,buf,len);    if (r == -1) if (errno == error_intr) continue;    return r;  }}static int getthis(s,buf,len)register substdio *s;register char *buf;register int len;{  register int r;  register int q;   r = s->p;  q = r - len;  if (q > 0) { r = len; s->p = q; } else s->p = 0;  byte_copy(buf,r,s->x + s->n);  s->n += r;  return r;}int substdio_feed(s)register substdio *s;{  register int r;  register int q;  if (s->p) return s->p;  q = s->n;  r = oneread(s->op,s->fd,s->x,q);  if (r <= 0) return r;  s->p = r;  q -= r;  s->n = q;  if (q > 0) /* damn, gotta shift */ byte_copyr(s->x + q,r,s->x);  return r;}int substdio_bget(s,buf,len)register substdio *s;register char *buf;register int len;{  register int r;   if (s->p > 0) return getthis(s,buf,len);  r = s->n; if (r <= len) return oneread(s->op,s->fd,buf,r);  r = substdio_feed(s); if (r <= 0) return r;  return getthis(s,buf,len);}int substdio_get(s,buf,len)register substdio *s;register char *buf;register int len;{  register int r;   if (s->p > 0) return getthis(s,buf,len);  if (s->n <= len) return oneread(s->op,s->fd,buf,len);  r = substdio_feed(s); if (r <= 0) return r;  return getthis(s,buf,len);}char *substdio_peek(s)register substdio *s;{  return s->x + s->n;}void substdio_seek(s,len)register substdio *s;register int len;{  s->n += len;  s->p -= len;}