1 /*
2 * Copyright (c) 1987, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #include "config.h"
35
36 #if defined(LIBC_SCCS) && !defined(lint)
37 static const char sccsid[] = "@(#)getenv.c 8.1 (Berkeley) 6/4/93";
38 static const char sccsid[] = "@(#)setenv.c 8.1 (Berkeley) 6/4/93";
39 #endif /* LIBC_SCCS and not lint */
40 #else
41 __RCSID("$NetBSD: env.c,v 1.2 2014/01/26 21:43:45 christos Exp $");
42 #endif
43
44 #include <stdlib.h>
45 #include <string.h>
46
47 /*
48 * __findenv --
49 * Returns pointer to value associated with name, if any, else NULL.
50 * Sets offset to be the offset of the name/value combination in the
51 * environmental array, for use by setenv(3) and unsetenv(3).
52 * Explicitly removes '=' in argument name.
53 *
54 * This routine *should* be a static; don't use it.
55 */
56 static char *
__findenv(register char * name,int * offset)57 __findenv(register char *name, int *offset)
58 {
59 extern char **environ;
60 register int len;
61 register char *np;
62 register char **p, *c;
63
64 if (name == NULL || environ == NULL)
65 return (NULL);
66 for (np = name; *np && *np != '='; ++np)
67 continue;
68 len = np - name;
69 for (p = environ; (c = *p) != NULL; ++p)
70 if (strncmp(c, name, len) == 0 && c[len] == '=') {
71 *offset = p - environ;
72 return (c + len + 1);
73 }
74 return (NULL);
75 }
76
77 #ifndef HAVE_SETENV
78 /*
79 * setenv --
80 * Set the value of the environmental variable "name" to be
81 * "value". If rewrite is set, replace any current value.
82 *
83 * PUBLIC: #ifndef HAVE_SETENV
84 * PUBLIC: int setenv __P((const char *, const char *, int));
85 * PUBLIC: #endif
86 */
setenv(name,value,rewrite)87 setenv(name, value, rewrite)
88 register char *name;
89 register char *value;
90 int rewrite;
91 {
92 extern char **environ;
93 static int alloced; /* if allocated space before */
94 register char *c;
95 int l_value, offset;
96
97 if (*value == '=') /* no `=' in value */
98 ++value;
99 l_value = strlen(value);
100 if ((c = __findenv(name, &offset))) { /* find if already exists */
101 if (!rewrite)
102 return (0);
103 if (strlen(c) >= l_value) { /* old larger; copy over */
104 while (*c++ = *value++);
105 return (0);
106 }
107 } else { /* create new slot */
108 register int cnt;
109 register char **p;
110
111 for (p = environ, cnt = 0; *p; ++p, ++cnt);
112 if (alloced) { /* just increase size */
113 environ = (char **)realloc((char *)environ,
114 (size_t)(sizeof(char *) * (cnt + 2)));
115 if (!environ)
116 return (-1);
117 }
118 else { /* get new space */
119 alloced = 1; /* copy old entries into it */
120 p = malloc((size_t)(sizeof(char *) * (cnt + 2)));
121 if (!p)
122 return (-1);
123 memmove(p, environ, cnt * sizeof(char *));
124 environ = p;
125 }
126 environ[cnt + 1] = NULL;
127 offset = cnt;
128 }
129 for (c = (char *)name; *c && *c != '='; ++c); /* no `=' in name */
130 if (!(environ[offset] = /* name + `=' + value */
131 malloc((size_t)((int)(c - name) + l_value + 2))))
132 return (-1);
133 for (c = environ[offset]; (*c = *name++) && *c != '='; ++c);
134 for (*c++ = '='; *c++ = *value++;);
135 return (0);
136 }
137 #endif
138
139 #ifndef HAVE_UNSETENV
140 /*
141 * unsetenv(name) --
142 * Delete environmental variable "name".
143 *
144 * PUBLIC: #ifndef HAVE_UNSETENV
145 * PUBLIC: void unsetenv __P((const char *));
146 * PUBLIC: #endif
147 */
148 void
unsetenv(name)149 unsetenv(name)
150 char *name;
151 {
152 extern char **environ;
153 register char **p;
154 int offset;
155
156 while (__findenv(name, &offset)) /* if set multiple times */
157 for (p = &environ[offset];; ++p)
158 if (!(*p = *(p + 1)))
159 break;
160 }
161 #endif
162