/* environ.c -- library for manipulating environments for GNU.   Copyright (C) 1986, 1989 Free Software Foundation, Inc.This program is free software; you can redistribute it and/or modifyit under the terms of the GNU General Public License as published bythe Free Software Foundation; either version 2 of the License, or(at your option) any later version.This program is distributed in the hope that it will be useful,but WITHOUT ANY WARRANTY; without even the implied warranty ofMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See theGNU General Public License for more details.You should have received a copy of the GNU General Public Licensealong with this program; if not, write to the Free SoftwareFoundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */#define min(a, b) ((a) < (b) ? (a) : (b))#define max(a, b) ((a) > (b) ? (a) : (b))#include "defs.h"#include "environ.h"#include <string.h>#include "defs.h" /* For strsave().  *//* Return a new environment object.  */struct environ *make_environ (){  register struct environ *e;  e = (struct environ *) xmalloc (sizeof (struct environ));  e->allocated = 10;  e->vector = (char **) xmalloc ((e->allocated + 1) * sizeof (char *));  e->vector[0] = 0;  return e;}/* Free an environment and all the strings in it.  */voidfree_environ (e)     register struct environ *e;{  register char **vector = e->vector;  while (*vector)    free (*vector++);  free (e);}/* Copy the environment given to this process into E.   Also copies all the strings in it, so we can be sure   that all strings in these environments are safe to free.  */voidinit_environ (e)     register struct environ *e;{  extern char **environ;  register int i;  for (i = 0; environ[i]; i++) /*EMPTY*/;  if (e->allocated < i)    {      e->allocated = max (i, e->allocated + 10);      e->vector = (char **) xrealloc ((char *)e->vector,				      (e->allocated + 1) * sizeof (char *));    }  memcpy (e->vector, environ, (i + 1) * sizeof (char *));  while (--i >= 0)    {      register int len = strlen (e->vector[i]);      register char *new = (char *) xmalloc (len + 1);      memcpy (new, e->vector[i], len + 1);      e->vector[i] = new;    }}/* Return the vector of environment E.   This is used to get something to pass to execve.  */char **environ_vector (e)     struct environ *e;{  return e->vector;}/* Return the value in environment E of variable VAR.  */char *get_in_environ (e, var)     const struct environ *e;     const char *var;{  register int len = strlen (var);  register char **vector = e->vector;  register char *s;  for (; (s = *vector) != NULL; vector++)    if (!strncmp (s, var, len)	&& s[len] == '=')      return &s[len + 1];  return 0;}/* Store the value in E of VAR as VALUE.  */voidset_in_environ (e, var, value)     struct environ *e;     const char *var;     const char *value;{  register int i;  register int len = strlen (var);  register char **vector = e->vector;  register char *s;  for (i = 0; (s = vector[i]) != NULL; i++)    if (!strncmp (s, var, len)	&& s[len] == '=')      break;  if (s == 0)    {      if (i == e->allocated)	{	  e->allocated += 10;	  vector = (char **) xrealloc ((char *)vector,				       (e->allocated + 1) * sizeof (char *));	  e->vector = vector;	}      vector[i + 1] = 0;    }  else    free (s);  s = (char *) xmalloc (len + strlen (value) + 2);  strcpy (s, var);  strcat (s, "=");  strcat (s, value);  vector[i] = s;  /* Certain variables get exported back to the parent (e.g. our)      environment, too.  */  if (!strcmp(var, "PATH")			/* Object file location */   || !strcmp (var, "G960BASE") 		/* Intel 960 downloads */   || !strcmp (var, "G960BIN") 			/* Intel 960 downloads */   || !strcmp (var, "GNUTARGET")		/* BFD object file type */				) {    putenv (strsave (s));  }  return;}/* Remove the setting for variable VAR from environment E.  */voidunset_in_environ (e, var)     struct environ *e;     char *var;{  register int len = strlen (var);  register char **vector = e->vector;  register char *s;  for (; (s = *vector) != NULL; vector++)    if (!strncmp (s, var, len)	&& s[len] == '=')      {	free (s);	memcpy (vector, vector + 1,		(e->allocated - (vector - e->vector)) * sizeof (char *));	e->vector[e->allocated - 1] = 0;	return;      }}