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 #if defined(LIBC_SCCS) && !defined(lint)
35 static const char sccsid[] = "@(#)getenv.c 8.1 (Berkeley) 6/4/93";
36 static const char sccsid[] = "@(#)setenv.c 8.1 (Berkeley) 6/4/93";
37 #endif /* LIBC_SCCS and not lint */
38
39 #include <stdlib.h>
40 #include <string.h>
41
42 /*
43 * __findenv --
44 * Returns pointer to value associated with name, if any, else NULL.
45 * Sets offset to be the offset of the name/value combination in the
46 * environmental array, for use by setenv(3) and unsetenv(3).
47 * Explicitly removes '=' in argument name.
48 *
49 * This routine *should* be a static; don't use it.
50 */
51 static char *
__findenv(name,offset)52 __findenv(name, offset)
53 register const char *name;
54 int *offset;
55 {
56 extern char **environ;
57 register int len;
58 register const char *np;
59 register char **p, *c;
60
61 if (name == NULL || environ == NULL)
62 return (NULL);
63 for (np = name; *np && *np != '='; ++np)
64 continue;
65 len = np - name;
66 for (p = environ; (c = *p) != NULL; ++p)
67 #ifdef WIN32
68 if (strnicmp(c, name, len) == 0 && c[len] == '=') {
69 #else
70 if (strncmp(c, name, len) == 0 && c[len] == '=') {
71 #endif
72 *offset = p - environ;
73 return (c + len + 1);
74 }
75 return (NULL);
76 }
77
78 static char *
par_getenv(name)79 par_getenv(name)
80 const char *name;
81 {
82 int i;
83
84 return __findenv(name, &i);
85 }
86
87 /*
88 * setenv --
89 * Set the value of the environmental variable "name" to be
90 * "value". If rewrite is set, replace any current value.
91 */
92 static int
par_setenv(name,value)93 par_setenv(name, value)
94 const char *name;
95 register const char *value;
96 {
97 #ifdef WIN32
98 char* p = (char*)malloc((size_t)(strlen(name) + strlen(value) + 2));
99 if (!p)
100 return (-1);
101 sprintf(p, "%s=%s", name, value);
102 _putenv(p);
103 return (0);
104 #else
105 extern char **environ;
106 static int alloced = 0; /* if allocated space before */
107 register char *c;
108 size_t l_value;
109 int offset;
110
111 if (*value == '=') /* no `=' in value */
112 ++value;
113 l_value = strlen(value);
114 if ((c = __findenv(name, &offset))) { /* find if already exists */
115 if (strlen(c) >= l_value) { /* old larger; copy over */
116 while ((*c++ = *value++));
117 return (0);
118 }
119 } else { /* create new slot */
120 register int cnt;
121 register char **p;
122
123 for (p = environ, cnt = 0; *p; ++p, ++cnt);
124 if (alloced) { /* just increase size */
125 environ = (char **)realloc((char *)environ,
126 (size_t)(sizeof(char *) * (cnt + 2)));
127 if (!environ)
128 return (-1);
129 }
130 else { /* get new space */
131 alloced = 1; /* copy old entries into it */
132 p = malloc((size_t)(sizeof(char *) * (cnt + 2)));
133 if (!p)
134 return (-1);
135 memmove(p, environ, cnt * sizeof(char *));
136 environ = p;
137 }
138 environ[cnt + 1] = NULL;
139 offset = cnt;
140 }
141 for (c = (char *)name; *c && *c != '='; ++c); /* no `=' in name */
142 if (!(environ[offset] = /* name + `=' + value */
143 malloc((size_t)((int)(c - name) + l_value + 2))))
144 return (-1);
145 for (c = environ[offset]; (*c = *name++) && *c != '='; ++c);
146 for (*c++ = '='; (*c++ = *value++););
147 return (0);
148 #endif
149 }
150
151 /*
152 * unsetenv(name) --
153 * Delete environmental variable "name".
154 */
155 static void
par_unsetenv(name)156 par_unsetenv(name)
157 const char *name;
158 {
159 #ifdef WIN32
160 par_setenv(name, "");
161 #else
162 extern char **environ;
163 register char **p;
164 int offset;
165
166 while (__findenv(name, &offset)) /* if set multiple times */
167 for (p = &environ[offset];; ++p)
168 if (!(*p = *(p + 1)))
169 break;
170 #endif
171 }
172