1 /* $NetBSD: putenv.c,v 1.1.1.1 2016/01/13 18:41:48 christos Exp $ */
2
3 /* Copyright (C) 1991, 2001 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Library General Public License as
8 published by the Free Software Foundation; either version 2 of the
9 License, or (at your option) any later version.
10
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Library General Public License for more details.
15
16 You should have received a copy of the GNU Library General Public
17 License along with the GNU C Library; see the file COPYING.LIB. If
18 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
19 Cambridge, MA 02139, USA. */
20
21 /* Hacked slightly by jjc@jclark.com for groff. */
22
23 #ifdef HAVE_CONFIG_H
24 #include <config.h>
25 #endif
26
27 #include <string.h>
28
29 #ifdef __STDC__
30 #include <stddef.h>
31 typedef void *PTR;
32 typedef size_t SIZE_T;
33 #else /* not __STDC__ */
34 typedef char *PTR;
35 typedef int SIZE_T;
36 #endif /* not __STDC__ */
37
38 #ifdef HAVE_STDLIB_H
39 #include <stdlib.h>
40 #else /* not HAVE_STDLIB_H */
41 PTR malloc();
42 #endif /* not HAVE_STDLIB_H */
43
44 #ifndef NULL
45 #define NULL 0
46 #endif
47
48 extern char **environ;
49
50 /* Put STRING, which is of the form "NAME=VALUE", in the environment. */
51
putenv(const char * string)52 int putenv(const char *string)
53 {
54 char *name_end = strchr(string, '=');
55 SIZE_T size;
56 char **ep;
57
58 if (name_end == NULL)
59 {
60 /* Remove the variable from the environment. */
61 size = strlen(string);
62 for (ep = environ; *ep != NULL; ++ep)
63 if (!strncmp(*ep, string, size) && (*ep)[size] == '=')
64 {
65 while (ep[1] != NULL)
66 {
67 ep[0] = ep[1];
68 ++ep;
69 }
70 *ep = NULL;
71 return 0;
72 }
73 }
74
75 size = 0;
76 for (ep = environ; *ep != NULL; ++ep)
77 if (!strncmp(*ep, string, name_end - string)
78 && (*ep)[name_end - string] == '=')
79 break;
80 else
81 ++size;
82
83 if (*ep == NULL)
84 {
85 static char **last_environ = NULL;
86 char **new_environ = (char **) malloc((size + 2) * sizeof(char *));
87 if (new_environ == NULL)
88 return -1;
89 (void) memcpy((PTR) new_environ, (PTR) environ, size * sizeof(char *));
90 new_environ[size] = (char *) string;
91 new_environ[size + 1] = NULL;
92 if (last_environ != NULL)
93 free((PTR) last_environ);
94 last_environ = new_environ;
95 environ = new_environ;
96 }
97 else
98 *ep = (char *) string;
99
100 return 0;
101 }
102