/* get_env.c - A getenv() replacement.

 * Copyright (C) 2003, 2004 g10 Code GmbH

 *

 * This file is part of GPGME.

 *

 * GPGME 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.

 *

 * GPGME 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 this program; if not, see <https://gnu.org/licenses/>.

 * SPDX-License-Identifier: LGPL-2.1-or-later

 */

#if HAVE_CONFIG_H

#include <config.h>

#endif

#include <stdlib.h>

#include <errno.h>

#include <string.h>

#include "util.h"

/* Retrieve the environment variable NAME and return a copy of it in a

   malloc()'ed buffer in *VALUE.  If the environment variable is not

   set, return NULL in *VALUE.  */

#ifdef HAVE_GETENV_R

#define INITIAL_GETENV_SIZE 32

gpgme_error_t

_gpgme_getenv (const char *name, char **value)

{

  size_t len = INITIAL_GETENV_SIZE;

  char *env_value;

  env_value = malloc (len);

  while (1)

    {

      *value = env_value;

      if (!env_value)

        return gpg_error_from_syserror ();

      if (getenv_r (name, env_value, len) == 0)

        break;

      if (errno == ERANGE)

        {

          len *= 2;

          env_value = realloc (env_value, len);

        }

      else

        {

          int saved = errno;

          free (env_value);

          *value = NULL;

          if (errno == ENOENT)

            return 0;

          else

          return gpg_error_from_errno (saved);

        }

    }

  return 0;

}

#else

#ifndef HAVE_THREAD_SAFE_GETENV

GPGRT_LOCK_DEFINE (environ_lock);

#endif

gpgme_error_t

_gpgme_getenv (const char *name, char **value)

{

  char *env_value;

  gpgme_error_t err = 0;

#ifndef HAVE_THREAD_SAFE_GETENV

  gpg_err_code_t rc;

  rc= gpgrt_lock_lock (&environ_lock);

  if (rc)

    {

      err = gpg_error (rc);

      goto leave;

    }

#endif

  env_value = getenv (name);

  if (!env_value)

    *value = NULL;

  else

    {

      *value = strdup (env_value);

      if (!*value)

	err = gpg_error_from_syserror ();

    }

#ifndef HAVE_THREAD_SAFE_GETENV

  rc = gpgrt_lock_unlock (&environ_lock);

  if (rc)

    err = gpg_error (rc);

 leave:

#endif

  return err;

}

#endif