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