sysdeps/generic/getenv.c

   1 /* Copyright (C) 1991, 1992, 1994, 1996 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 Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    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    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 #include <errno.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <unistd.h>
  23
  24 #ifndef HAVE_GNU_LD
  25 #define __environ       environ
  26 #endif
  27
  28 /* Return the value of the environment variable NAME.  */
  29 char *
  30 getenv (name)
  31      const char *name;
  32 {
  33   const size_t len = strlen (name);
  34   char **ep;
  35
  36   if (__environ == NULL)
  37     return NULL;
  38
  39   for (ep = __environ; *ep != NULL; ++ep)
  40     if (!strncmp (*ep, name, len) && (*ep)[len] == '=')
  41       return &(*ep)[len + 1];
  42
  43   return NULL;
  44 }