lxstat.c

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,是提高功力的好资料

/* lxstat using old-style Unix lstat system call.
   Copyright (C) 1991, 1995, 1996, 1997, 1998, 2000, 2002, 2003, 2004
   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.  */

/* Ho hum, since xstat == xstat64 we must get rid of the prototype or gcc
   will complain since they don't strictly match.  */
#define __lxstat64 __lxstat64_disable

#include <errno.h>
#include <stddef.h>
#include <sys/stat.h>

#include <sysdep.h>
#include <sys/syscall.h>
#include <bp-checks.h>

/* Get information about the file FD in BUF.  */
int
__lxstat (int vers, const char *name, struct stat *buf)
{
  if (vers == _STAT_VER_KERNEL || vers == _STAT_VER_LINUX)
    return INLINE_SYSCALL (lstat, 2, CHECK_STRING (name), CHECK_1 (buf));

  __set_errno (EINVAL);
  return -1;
}

hidden_def (__lxstat)
weak_alias (__lxstat, _lxstat);
#undef __lxstat64
strong_alias (__lxstat, __lxstat64);
hidden_ver (__lxstat, __lxstat64)