__sseek
fp->_seek = __sseek;
._seek = __sseek, \
fp->_seek = __sseek;
(void) __sseek((void *)fp, (off_t)0, SEEK_END);
fp->_seek = __sseek;
(void) __sseek((void *)fp, (off_t)0, SEEK_END);
if (seekfn != __sseek ||
extern off_t __sseek(void *, off_t, int);
return (st.st_mode & S_IFMT) == S_IFREG && fp->_seek == __sseek ?