#include"stdio_impl.h"staticoff_tretneg1(FILE*f,off_toff,intwhence){return-1;}off_t__stdio_seek(FILE*f,off_toff,intwhence){off_tret=__syscall_lseek(f->fd,off,whence);/* Detect unseekable files and optimize future failures out */if(ret<0&&off==0&&whence==SEEK_CUR)f->seek=retneg1;returnret;}