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