glibc/io/getwd.c

/* Obsolete function to get current working directory.
   Copyright (C) 1991-2019 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, see
   <https://www.gnu.org/licenses/>.  */

#include <errno.h>
#include <limits.h>
#include <string.h>
#include <unistd.h>


char *
getwd (char *buf)
{
#ifndef PATH_MAX
#define PATH_MAX 1024
#endif
  char tmpbuf[PATH_MAX];

  if (buf == NULL)
    {
      __set_errno (EINVAL);
      return NULL;
    }

  if (__getcwd (tmpbuf, PATH_MAX) == NULL)
    {
      /* We use 1024 here since it should really be enough and because
	 this is a safe value.  */
      __strerror_r (errno, buf, 1024);
      return NULL;
    }

  /* This is completely unsafe.  Nobody can say how big the user
     provided buffer is.  Perhaps the application and the libc
     disagree about the value of PATH_MAX.  */
  return strcpy (buf, tmpbuf);
}

link_warning (getwd,
	      "the `getwd' function is dangerous and should not be used.")