seekdir.c

来自「glibc 库, 不仅可以学习使用库函数,还可以学习函数的具体实现,是提高功力的」· C语言 代码 · 共 41 行

/* Copyright (C) 1993, 94, 95, 96, 97, 99 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <errno.h>
#include <stddef.h>
#include <dirent.h>
#include <unistd.h>
#include "dirstream.h"

/* Seek to position POS in DIRP.  */
/* XXX should be __seekdir ? */
void
seekdir (dirp, pos)
     DIR *dirp;
     long int pos;
{
  __libc_lock_lock (dirp->__lock);
  /* Change our entry index pointer to POS and discard any data already
     read.  The next `readdir' call will notice the empty block and read
     anew from the location in DIRP->__entry_ptr and reset the other state
     variables.  */
  dirp->__entry_ptr = pos;
  dirp->__size = 0;
  __libc_lock_unlock (dirp->__lock);
}