1 /* Routines for dealing with '\0' separated environment vectors
2    Copyright (C) 1995-2022 Free Software Foundation, Inc.
3    This file is part of the GNU C Library.
4 
5    The GNU C Library is free software; you can redistribute it and/or
6    modify it under the terms of the GNU Lesser General Public
7    License as published by the Free Software Foundation; either
8    version 2.1 of the License, or (at your option) any later version.
9 
10    The GNU C Library is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13    Lesser General Public License for more details.
14 
15    You should have received a copy of the GNU Lesser General Public
16    License along with the GNU C Library; if not, see
17    <https://www.gnu.org/licenses/>.  */
18 
19 #ifndef _ENVZ_H
20 #define _ENVZ_H	1
21 
22 #include <features.h>
23 
24 #include <errno.h>
25 
26 /* Envz's are argz's too, and should be created etc., using the same
27    routines.  */
28 #include <argz.h>
29 
30 __BEGIN_DECLS
31 
32 /* Returns a pointer to the entry in ENVZ for NAME, or 0 if there is none.  */
33 extern char *envz_entry (const char *__restrict __envz, size_t __envz_len,
34 			 const char *__restrict __name)
35      __THROW __attribute_pure__;
36 
37 /* Returns a pointer to the value portion of the entry in ENVZ for NAME, or 0
38    if there is none.  */
39 extern char *envz_get (const char *__restrict __envz, size_t __envz_len,
40 		       const char *__restrict __name)
41      __THROW __attribute_pure__;
42 
43 /* Adds an entry for NAME with value VALUE to ENVZ & ENVZ_LEN.  If an entry
44    with the same name already exists in ENVZ, it is removed.  If VALUE is
45    NULL, then the new entry will a special null one, for which envz_get will
46    return NULL, although envz_entry will still return an entry; this is handy
47    because when merging with another envz, the null entry can override an
48    entry in the other one.  Null entries can be removed with envz_strip ().  */
49 extern error_t envz_add (char **__restrict __envz,
50 			 size_t *__restrict __envz_len,
51 			 const char *__restrict __name,
52 			 const char *__restrict __value) __THROW;
53 
54 /* Adds each entry in ENVZ2 to ENVZ & ENVZ_LEN, as if with envz_add().  If
55    OVERRIDE is true, then values in ENVZ2 will supersede those with the same
56    name in ENV, otherwise not.  */
57 extern error_t envz_merge (char **__restrict __envz,
58 			   size_t *__restrict __envz_len,
59 			   const char *__restrict __envz2,
60 			   size_t __envz2_len, int __override) __THROW;
61 
62 /* Remove the entry for NAME from ENVZ & ENVZ_LEN, if any.  */
63 extern void envz_remove (char **__restrict __envz,
64 			 size_t *__restrict __envz_len,
65 			 const char *__restrict __name) __THROW;
66 
67 /* Remove null entries.  */
68 extern void envz_strip (char **__restrict __envz,
69 			size_t *__restrict __envz_len) __THROW;
70 
71 __END_DECLS
72 
73 #endif /* envz.h */
74