/* Routines for dealing with '\0' separated environment vectors
Copyright (C) 1995, 96, 98, 99, 2000 Free Software Foundation, Inc.
This file is part of the GNU C Library.

The GNU C Library 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.

The GNU C Library 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 the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */

#ifndef _ENVZ_H
#define _ENVZ_H 1

#include <features.h>

#include <errno.h>

/* Envz's are argz's too, and should be created etc., using the same
routines. */
#include <argz.h>

__BEGIN_DECLS

/* Returns a pointer to the entry in ENVZ for NAME, or 0 if there is none. */
extern char *envz_entry (__const char *__restrict __envz, size_t __envz_len,
__const char *__restrict __name)
__THROW __attribute_pure__;

/* Returns a pointer to the value portion of the entry in ENVZ for NAME, or 0
if there is none. */
extern char *envz_get (__const char *__restrict __envz, size_t __envz_len,
__const char *__restrict __name)
__THROW __attribute_pure__;

/* Adds an entry for NAME with value VALUE to ENVZ & ENVZ_LEN. If an entry
with the same name already exists in ENVZ, it is removed. If VALUE is
NULL, then the new entry will a special null one, for which envz_get will
return NULL, although envz_entry will still return an entry; this is handy
because when merging with another envz, the null entry can override an
entry in the other one. Null entries can be removed with envz_strip (). */
extern error_t envz_add (char **__restrict __envz,
size_t *__restrict __envz_len,
__const char *__restrict __name,
__const char *__restrict __value) __THROW;

/* Adds each entry in ENVZ2 to ENVZ & ENVZ_LEN, as if with envz_add(). If
OVERRIDE is true, then values in ENVZ2 will supersede those with the same
name in ENV, otherwise not. */
extern error_t envz_merge (char **__restrict __envz,
size_t *__restrict __envz_len,
__const char *__restrict __envz2,
size_t __envz2_len, int __override) __THROW;

/* Remove the entry for NAME from ENVZ & ENVZ_LEN, if any. */
extern void envz_remove (char **__restrict __envz,
size_t *__restrict __envz_len,
__const char *__restrict __name) __THROW;

/* Remove null entries. */
extern void envz_strip (char **__restrict __envz,
size_t *__restrict __envz_len) __THROW;

__END_DECLS

#endif /* envz.h */