/* Environment handling for dynamic loader.

   Copyright (C) 1995-2018 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

   <http://www.gnu.org/licenses/>.  */

#include <string.h>

#include <stdlib.h>

#include <unistd.h>

#include <ldsodefs.h>

/* Walk through the environment of the process and return all entries

   starting with `LD_'.  */

char *

_dl_next_ld_env_entry (char ***position)

{

  char **current = *position;

  char *result = NULL;

  while (*current != NULL)

    {

      if (__builtin_expect ((*current)[0] == 'L', 0)

	  && (*current)[1] == 'D' && (*current)[2] == '_')

	{

	  result = &(*current)[3];

	  /* Save current position for next visit.  */

	  *position = ++current;

	  break;

	}

      ++current;

    }

  return result;

}

/* In ld.so __environ is not exported.  */

extern char **__environ attribute_hidden;

int

unsetenv (const char *name)

{

  char **ep;

  ep = __environ;

  while (*ep != NULL)

    {

      size_t cnt = 0;

      while ((*ep)[cnt] == name[cnt] && name[cnt] != '\0')

	++cnt;

      if (name[cnt] == '\0' && (*ep)[cnt] == '=')

	{

	  /* Found it.  Remove this pointer by moving later ones to

	     the front.  */

	  char **dp = ep;

	  do

	    dp[0] = dp[1];

	  while (*dp++);

	  /* Continue the loop in case NAME appears again.  */

	}

      else

	++ep;

    }

  return 0;

}