/* getenv.c - get environment variable value from the shell's variable	      list. *//* Copyright (C) 1997 Free Software Foundation, Inc.   This file is part of GNU Bash, the Bourne Again SHell.   Bash is free software; you can redistribute it and/or modify it under   the terms of the GNU General Public License as published by the Free   Software Foundation; either version 2, or (at your option) any later   version.   Bash 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 General Public License   for more details.   You should have received a copy of the GNU General Public License along   with Bash; see the file COPYING.  If not, write to the Free Software   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA */#include <config.h>#if defined (CAN_REDEFINE_GETENV)#if defined (HAVE_UNISTD_H)#  include <unistd.h>#endif#include <bashansi.h>#include <shell.h>extern char **environ;/* We supply our own version of getenv () because we want library   routines to get the changed values of exported variables. *//* The NeXT C library has getenv () defined and used in the same file.   This screws our scheme.  However, Bash will run on the NeXT using   the C library getenv (), since right now the only environment variable   that we care about is HOME, and that is already defined.  */static char *last_tempenv_value = (char *)NULL;char *getenv (name)#if defined (__linux__) || defined (__bsdi__) || defined (convex)     const char *name;#else     char const *name;#endif /* !__linux__ && !__bsdi__ && !convex */{  SHELL_VAR *var;  var = find_tempenv_variable ((char *)name);  if (var)    {      FREE (last_tempenv_value);      last_tempenv_value = value_cell (var) ? savestring (value_cell (var)) : (char *)NULL;      dispose_variable (var);      return (last_tempenv_value);    }  else if (shell_variables)    {      var = find_variable ((char *)name);      if (var && exported_p (var))	return (value_cell (var));    }  else    {      register int i, len;      /* In some cases, s5r3 invokes getenv() before main(); BSD systems	 using gprof also exhibit this behavior.  This means that	 shell_variables will be 0 when this is invoked.  We look up the	 variable in the real environment in that case. */      for (i = 0, len = strlen (name); environ[i]; i++)	{	  if ((STREQN (environ[i], name, len)) && (environ[i][len] == '='))	    return (environ[i] + len + 1);	}    }  return ((char *)NULL);}/* Some versions of Unix use _getenv instead. */char *_getenv (name)#if defined (__linux__) || defined (__bsdi__) || defined (convex)     const char *name;#else     char const *name;#endif /* !__linux__ && !__bsdi__ && !convex */{  return (getenv (name));}#endif /* CAN_REDEFINE_GETENV */