1  /* Copyright (C) 1991-2023 Free Software Foundation, Inc.
       2     This file is part of the GNU C Library.
       3  
       4     The GNU C Library is free software; you can redistribute it and/or
       5     modify it under the terms of the GNU Lesser General Public
       6     License as published by the Free Software Foundation; either
       7     version 2.1 of the License, or (at your option) any later version.
       8  
       9     The GNU C Library is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      12     Lesser General Public License for more details.
      13  
      14     You should have received a copy of the GNU Lesser General Public
      15     License along with the GNU C Library; if not, see
      16     <https://www.gnu.org/licenses/>.  */
      17  
      18  #include <stdlib.h>
      19  #include <string.h>
      20  #include <unistd.h>
      21  
      22  char *
      23  getenv (const char *name)
      24  {
      25    if (__environ == NULL || name[0] == '\0')
      26      return NULL;
      27  
      28    size_t len = strlen (name);
      29    for (char **ep = __environ; *ep != NULL; ++ep)
      30      {
      31        if (name[0] == (*ep)[0]
      32  	  && strncmp (name, *ep, len) == 0 && (*ep)[len] == '=')
      33  	return *ep + len + 1;
      34      }
      35  
      36    return NULL;
      37  }
      38  libc_hidden_def (getenv)